Skin Protocol

The Skin Protocol is True Health's nine-product systems-biology stack built around the four mechanisms behind visible skin aging: collagen-fiber loss (≈1%/year after age 20, accelerating to ≈30% in the first five post-menopausal years per Brincat 1987), UV/IR-A photoaging via the AP-1 / MMP-1-collagenase cascade (Fisher 1996/2002), AGE cross-linking on long-lived dermal collagen (Gkogkolou 2012), and stratum-corneum / dermal-HA decline that drives barrier dysfunction and TEWL (Kawada 2014, Choi 2007). Every SKU on this page maps onto a specific mechanism with a published-trial dose anchor — no proprietary blends, no underdosed actives, no "youth-restoring" claims the literature can't support. If you've tried single-ingredient collagen and felt nothing, are reading The Beauty of Dirty Skin (Bowe), The Skincare Bible (Mahto), or the photoaging chapter in Sinclair's Lifespan and want to assemble the actual SKUs the literature describes, or are prepping for a microneedling/laser/peel series, this is the page that pairs the right products in the right order.

The 9 SKUs: Marine Collagen Peptides 5 g (Type-I, 2-3 kDa hydrolyzed), Multi-Collagen Peptides Powder 1 lb + Multi-Collagen Capsules (Types I, II, III, V, X) for substrate; Hyaluronic Acid 200 mg + Vit-C for hydration plus prolyl/lysyl-hydroxylase cofactor; Liposomal Vitamin C 1000 mg for higher plasma ascorbate (collagen synthesis is fully ascorbate-dependent, Murad 1981); Biotin 10,000 mcg for keratinocyte/follicle B-7 sufficiency; Glutathione 500 mg enteric-coated reduced GSH for melanin/AGE control; Astaxanthin 12 mg natural Haematococcus pluvialis for membrane-spanning UV protection; and the bundled Beauty & Longevity Stack entry kit. Trial-anchored doses: 5 g/day collagen peptides per Proksch 2014 / Asserin 2015 / Bolke 2019 (8-12 weeks to first measurable elasticity/wrinkle change), 200 mg/day low-MW HA per Oe 2017 / Kawada 2014, 1000 mg/day vitamin C per Davis 2016 (liposomal AUC ≥1.7× plain), 250-500 mg/day reduced GSH per Handog 2016, 12 mg/day astaxanthin per Tominaga 2012 / Ito 2018. Every product is third-party tested to USP <2021> / <2022> microbial limits, ICP-MS heavy metals against California Prop 65 and FDA EAFUS, cGMP per 21 CFR Part 111.

The 60-second skin-protocol answer

• What this collection is. Nine SKUs across four mechanism layers: substrate (3 collagen products), cofactors (HA + Vit-C, Liposomal Vit-C, Biotin), antioxidants (Glutathione, Astaxanthin), plus the Beauty & Longevity Stack bundle.
• Why your single-ingredient collagen didn't work. Collagen synthesis requires four cofactors (Murad 1981, Pinnell 2003): ascorbate for prolyl/lysyl hydroxylase (no Vit-C, no triple-helix), copper for lysyl oxidase, zinc for procollagen N-protease, biotin for the keratinocyte handoff. Marine collagen alone supplies the di-/tripeptide signal (Pro-Hyp, Hyp-Gly per Shigemura 2009 / Iwai 2005); without saturating ascorbate, new collagen polymerizes poorly.
• Four mechanisms behind visible aging. Type-I collagen falls 1%/year after 20 (Shuster 1975); 30% in five years post-menopause (Brincat 1987). UV/IR-A induce MMP-1/-3 collagenase via AP-1 (Fisher 1996/2002). Reactive carbonyls form irreversible AGE cross-links on dermal collagen (Gkogkolou 2012, Verzijl 2000). Dermal HA pool drops sharply after 40 (Meyer 1994), raising TEWL.
• Trial-anchored doses. 5 g/day hydrolyzed collagen × 8-12 weeks (Proksch 2014 elasticity +18%, Bolke 2019 wrinkles −20%, Asserin 2015 dermal HA +14%); 200 mg/day low-MW HA × 6-12 weeks (Oe 2017 moisture +8.5%); 1000 mg/day liposomal Vit-C (Davis 2016 AUC ≥1.7×); 250-500 mg/day reduced GSH × 12 weeks (Handog 2016 melanin index reduction); 12 mg/day natural astaxanthin × 8-12 weeks (Tominaga 2012, Ito 2018).
• Time to first signal. Hydration week 1-2; wrinkle/elasticity week 8-12; melanin/UV-spot 12 weeks; follicle/hair 12-26 weeks; dermal HA density 12 weeks; full barrier restoration 12-16 weeks. Photographic documentation (consistent lighting, 4 weeks apart) is the most reliable subjective endpoint.
• Quality bar. Marine collagen 2-3 kDa MW, ≥97% protein-by-Kjeldahl. HA ≤50 kDa for oral absorption (Kawada 2014). Astaxanthin natural Haematococcus-derived (synthetic 95:5 trans:cis ratio doesn't match algae's 100:0). Glutathione is reduced GSH (not GSSG) and enteric-coated. Liposomal Vit-C is true sunflower-lecithin liposome (not micelle marketing).
• Who this is for. Adults 30-50 in early-photoaging window; post-menopausal women in the Brincat decline window; men 35+ with dermal thinning; high-UV-region residents; pre-procedure microneedling/laser/peel patients (Park 2015); melasma/PIH cohorts; biological-age-test clients (TruDiagnostic SkinAge, Elysium Index Skin); skin-care users layering systemic with topical retinoid/L-ascorbic-acid/sunscreen.
• Who this is NOT for. Under-18 (skin still developing); pregnancy/lactation (defer biotin/GSH/astaxanthin to OB-GYN); active dermatitis flare; fish allergy (use multi-collagen route); active warfarin without prescriber sign-off; suspicious lesion pending dermatology evaluation.

On this page

1. The 60-second answer
2. Why a skin protocol exists — qualification filter
3. Skin biology — the four-mechanism aging spine
4. The three layers of the skin stack
5. Per-product trial evidence
6. Three protocol tiers
7. Cofactor stack — what pairs with what
8. Week-by-week realistic timeline
9. Cross-stacking with other True Health collections
10. Drug interactions and precautions
11. Who this protocol is for
12. Quality, sourcing, and analytical standards
13. Topical vs oral — what each does
14. How to measure improvement
15. Common myths and corrections
16. Cost tiers and what each one buys
17. FAQ
18. Reading list and primary references

Why a skin protocol exists — the qualification filter

Most "skin supplements" fail one or more of five filters; every SKU on this page passes all five.

1. Trial-anchored dose. The dose has been shown in a randomized human trial to move a dermatology-accepted endpoint: cutometer elasticity (Proksch 2014), corneometer hydration (Kawada 2014, Oe 2017), wrinkle volume on PRIMOS (Bolke 2019, Ito 2018), dermal-density ultrasound (Asserin 2015), Mexameter melanin index (Handog 2016), TEWL (Draelos 2017). No published RCT at the proposed dose with a real skin endpoint = doesn't qualify.
2. Mechanism completeness when paired. Collagen substrate alone is incomplete — synthesis is enzymatically dependent on ascorbate (prolyl/lysyl hydroxylase), copper (lysyl oxidase), and zinc (procollagen N-protease). Stacking marine peptides without the cofactor layer is the single most common reason supplement users feel nothing.
3. Independent purity verification. ICP-MS heavy metals against California Prop 65 and FDA EAFUS (mercury, cadmium, lead, arsenic limits matter for marine collagen — bioaccumulation in fish skin is real). HPLC identity testing for actives. ≥97% protein-by-Kjeldahl on collagen CoAs. ≥98% trans-isomer for astaxanthin. Reduced-GSH form (not GSSG) confirmed.
4. Manufacturing quality. cGMP per 21 CFR Part 111, FDA-registered facility audit. No proprietary blends. No titanium dioxide (banned as food additive in EU per EFSA 2021). Vegetable HPMC capsules. Per-batch CoA via support@.
5. Risk asymmetry. Bounded downside (oral collagen, HA, ascorbate, GSH all have human safety data at multiples of label dose; biotin's only flag is the immunoassay interference). Durable upside — skin-matrix changes documented at 8-26 weeks persist if dose continues.

Skin biology — the four-mechanism aging spine

The dermatology literature converges on four mechanisms behind visible skin aging. The Skin Protocol stack maps every SKU onto one or more — understanding the framework tells you which products to add or skip.

Mechanism 1: Collagen substrate decline (intrinsic + extrinsic)

Type-I collagen, ~80-85% of dermal matrix protein, falls ~1%/year after age 20 (Shuster 1975 J Invest Dermatol; Castelo-Branco 1992). The post-menopausal estrogen drop accelerates this to ~30% in five years (Brincat 1987). Hydrolyzed marine collagen peptides supply the bioactive di-/tripeptide signal (Pro-Hyp, Hyp-Gly, Gly-Pro-Hyp) that survives gastric digestion (Iwai 2005, Shigemura 2009) and reaches systemic circulation, stimulating dermal-fibroblast collagen synthesis (Asserin 2015). Multi-collagen blends add Type-II (cartilage), Type-III (early granulation), Type-V (DEJ basement membrane), Type-X (calcified cartilage) — fuller envelope when goal extends beyond skin. Stack target: 5 g/day hydrolyzed collagen × ≥8 weeks. SKUs: Marine Collagen 5 g, Multi-Collagen Powder, Multi-Collagen Capsules.

Mechanism 2: UV/IR-A photoaging — the MMP-1/-3 cascade

UV-A and IR-A activate AP-1 in keratinocytes and dermal fibroblasts, upregulating MMP-1 (interstitial collagenase) and MMP-3 (stromelysin) (Fisher 1996/1997/2002). MMP-1 cleaves Type-I collagen into 3/4 and 1/4 fragments the dermis can't repair fast enough during chronic UV exposure. The fibroblast simultaneously downregulates new collagen-I synthesis under UV stress, so net dermal collagen content falls. Astaxanthin is one of few molecules with documented MMP-1 suppression at oral dose: Tominaga 2012 (12 mg × 8 weeks) showed cutometer elasticity gain and crow's-feet wrinkle reduction; Ito 2018 (4 mg × 9 weeks) replicated. Vitamin C inhibits AP-1-driven MMP expression in keratinocytes (Pasonen-Seppänen 2008). Stack target: 12 mg/day natural astaxanthin + 1000 mg liposomal Vit-C; topical SPF 30+ remains primary defense.

Mechanism 3: Glycation and AGE cross-linking

Reactive dicarbonyls (methylglyoxal, glyoxal) and reducing sugars react non-enzymatically with collagen lysine and arginine residues, forming irreversible AGE cross-links — pentosidine, glucosepane, CML — that stiffen the dermal matrix and reduce elasticity (Gkogkolou 2012; Verzijl 2000). Dermal collagen has a half-life of ~15 years, so AGE accumulation is high in older dermis. Glycation also modifies elastin (Sell 1996). Glutathione is the primary endogenous detoxifier of methylglyoxal via the glyoxalase system (GLO1/GLO2). Reduced-GSH supplementation (Handog 2016: 500 mg × 12 weeks) lowered melanin index and improved skin smoothness on Visia analysis. Vitamin C has anti-glycation activity in vitro. Stack target: 500 mg/day enteric-coated reduced GSH + 1000 mg/day liposomal Vit-C.

Mechanism 4: Hydration / stratum corneum / DEJ — barrier function

The dermal hyaluronic acid pool drops markedly after age 40 (Meyer 1994), reducing dermal water-binding capacity. Stratum-corneum lipids (ceramides, cholesterol, fatty acids) decline in parallel, raising TEWL (Choi 2007). The dermal-epidermal junction flattens with age (Lavker 1987), reducing nutrient and oxygen exchange. Oral low-MW HA (≤50 kDa, ideally ≤10 kDa) is absorbed into systemic circulation (Kawada 2014), redistributes to skin, and increases dermal HA content with corresponding moisture and elasticity gains (Oe 2017; Göllner 2017). Vitamin C is the obligate cofactor for prolyl/lysyl hydroxylase building DEJ Type-IV and Type-VII collagen; biotin supports keratinocyte differentiation and the keratin-10/-14 axis. Stack target: 200 mg/day low-MW HA + Vit-C cofactor + 10,000 mcg biotin.

The three layers of the skin stack

Group the nine SKUs by what role they play. Build any skin protocol from scratch in this order: substrate first, cofactors second, antioxidants third. Skipping the cofactor layer is what makes single-ingredient collagen feel like a placebo for most users.

Layer 1: Collagen substrate. Supply the di-/tripeptide signal to dermal fibroblasts and amino-acid building blocks. Marine Collagen 5 g (Type-I hydrolyzed 2-3 kDa, the highest-evidence skin SKU); Multi-Collagen Powder 1 lb (5 types, 5 g/scoop, unflavored, 90 servings); Multi-Collagen Capsules 240 ct (same blend, capsule format).

Layer 2: Cofactors. The obligate enzymatic cofactors that turn ingested peptides into actual collagen triple-helix. HA 200 mg + Vit-C (two mechanism layers in one capsule); Liposomal Vit-C 1000 mg (sunflower-lecithin liposome, AUC ≥1.7× plain); Biotin 10,000 mcg (keratinocyte axis).

Layer 3: Antioxidants. Quench the reactive species driving MMP-1, AGE formation, melanin dysregulation. Astaxanthin 12 mg (natural Haematococcus, the only oral xanthophyll with documented MMP-1 suppression and crow's-feet endpoint per Tominaga 2012, Ito 2018); Glutathione 500 mg enteric-coated (master antioxidant + AGE detox + melanin balance per Handog 2016); Beauty & Longevity Stack bundle (Marine Collagen + Biotin + HA + Vit-C at protocol dose, 25% off vs separate-SKU; the canonical entry kit).

Per-product trial evidence

Every SKU is anchored to one or more published clinical trials. Quoted endpoints are the primary or co-primary outcome of the cited paper at the dose this product delivers; PMIDs are provided for reference.

Marine Collagen Peptides 5 g — Type-I Hydrolyzed

Hydrolyzed marine collagen at 2-3 kDa MW delivers Pro-Hyp, Hyp-Gly, and Gly-Pro-Hyp dipeptides into systemic circulation within 1-2 h of ingestion (Iwai 2005 J Agric Food Chem 53:6531-6536; Shigemura 2009 J Agric Food Chem 57:444-449). These peptides survive gastric digestion intact and act as both signaling molecules to dermal fibroblasts (upregulating Type-I procollagen mRNA, hyaluronic acid synthase HAS2/3) and as substrate for new collagen polymerization. Marine source delivers the highest Type-I purity of any commercially available collagen. Trial dose: 5 g/day × 8-12 weeks. Proksch 2014 Skin Pharmacol Physiol 27:113-119 (114 women, 5 g/day × 8 wk → cutometer skin elasticity +18% vs placebo). Asserin 2015 J Cosmet Dermatol 14:291-301 (106 women, 10 g/day × 8 wk → dermal collagen density +14% on ultrasound, dermal HA fragmentation reduced). Bolke 2019 Nutrients 11:2494 (72 women, 2.5 g specific bioactive collagen peptide × 12 wk → eye-wrinkle volume −20%, elasticity +7%, hydration +28%). Quality: Wild-caught marine source, ≥97% protein-by-Kjeldahl, mercury < 0.1 ppm, cadmium < 0.1 ppm by ICP-MS.

Multi-Collagen Peptides Powder — 5 Types, 1 lb

Five collagen types in one scoop — Type I (skin, bone, tendon), Type II (cartilage), Type III (early granulation, blood vessel walls), Type V (DEJ basement membrane), Type X (calcified cartilage at bone interface). Sourced from grass-fed bovine hide (I + III), chicken sternal cartilage (II + X), and eggshell membrane (V). Hydrolyzed for absorption, unflavored to mix into coffee, smoothies, water without taste interference. Trial dose: 5 g/scoop × 90 servings (1 lb tub = 90-day supply). Type-I/III evidence: Proksch 2014, Asserin 2015, Bolke 2019. Type-II joint: Lugo 2016 Nutr J 15:14. Type-V eggshell membrane: Aguirre 2018 Clin Interv Aging 13:235-245. Why pick this over marine: Goal extends beyond skin (joints, ligaments, gut, bone interface), or you're allergic to fish/shellfish. Powder is more economical per gram than capsules.

Multi-Collagen Complex Capsules — 240 ct

Same five-type blend as the powder above, capsule format for travel and no-mixing convenience. 240 capsules deliver the trial-anchored 5 g/day dose at 6 capsules per serving, 40-day supply per bottle. Capsule shell is vegetable-cellulose HPMC. Trial dose: 6 capsules/day × ≥8 weeks. Same Proksch 2014 / Asserin 2015 / Bolke 2019 evidence base as marine and multi-powder. Best for: Frequent travelers, office cohort that doesn't want to bring a powder tub to work, gift-buyers.

Hyaluronic Acid 200 mg + Vitamin C — Hydration + Cofactor Combo

Two skin-mechanism layers in one capsule. The HA component is low-MW oral HA (≤50 kDa, fragments ≤10 kDa for transepithelial absorption per Kawada 2014 Nutr J 13:70). Once absorbed and redistributed to dermis, oral HA increases dermal HA content and binds intracellular water, raising skin moisture and reducing TEWL. The Vit-C component is the obligate cofactor for prolyl-4-hydroxylase and lysyl hydroxylase — the enzymes that hydroxylate proline and lysine residues on procollagen, allowing the triple-helix to fold (Murad 1981 PNAS 78:2879). Without ascorbate at saturating dose, ingested collagen peptides give the body building blocks but the construction crew can't assemble them. Trial dose: 200 mg HA + 60 mg Vit-C per serving. HA: Oe 2017 Clin Cosmet Investig Dermatol 10:267-273 (60 women, 120 mg/day × 12 wk → skin moisture +8.5% on corneometer, fine wrinkles improved); Göllner 2017. Vit-C: Murad 1981 (mechanism); Pasonen-Seppänen 2008 J Invest Dermatol 128:797 (UV-induced AP-1 / MMP suppression).

Liposomal Vitamin C 1000 mg — Phospholipid-Encapsulated

True sunflower-lecithin liposome encapsulation packages L-ascorbic acid inside a phosphatidylcholine bilayer that bypasses the saturable SVCT2 transporter in the gut and delivers vitamin C to systemic circulation via lymphatic and chylomicron routes. Davis 2016 Nutr Metab Insights 9:25-30 measured plasma AUC ≥1.7× plain ascorbic acid at the same oral dose. Higher and longer-sustained plasma vitamin C is the single most important variable for collagen-synthesis support, melanin-stress mitigation, and AP-1/MMP-1 suppression in keratinocytes and fibroblasts. Trial dose: 1000 mg/day. Davis 2016 (bioavailability), Padayatty 2004 Ann Intern Med 140:533-537 (oral absorption saturation). Why this matters in the skin protocol: Marine collagen + biotin + HA without saturating ascorbate is the most common reason a skin stack underperforms — plain ascorbic acid at 1000 mg saturates SVCT2 and most of the dose passes unabsorbed; the liposomal route bypasses this ceiling.

Biotin 10,000 mcg — D-Biotin Maximum Strength

Biotin (vitamin B7) is an obligate cofactor for four mammalian carboxylases involved in fatty-acid synthesis (critical for sebocyte and stratum-corneum lipid production), gluconeogenesis, and amino-acid metabolism. In dermal/epidermal context, biotin sufficiency supports keratinocyte differentiation and the keratin-10/-14 axis (which builds the cornified envelope of the skin barrier) and follicle-cycle integrity. Frank deficiency causes alopecia, dermatitis, brittle nails (Lipner 2018 Skin Appendage Disord 4:181-187). Trial dose: 10,000 mcg D-biotin per softgel. Hochman 1993 Cutis 51:303-305 (2.5 mg/day × 6 mo → nail-plate thickness +25%); Patel 2017 Skin Appendage Disord 3:166-169 (review). Important caveat: Biotin at 10 mg/day interferes with streptavidin-biotin immunoassays (TSH, troponin, hCG, hormone panels). Stop biotin 72 hours before any blood draw. FDA Safety Communication 2017.

Glutathione 500 mg — Reduced GSH Enteric-Coated

Glutathione (γ-glutamyl-cysteinyl-glycine) is the body's master endogenous antioxidant and the principal substrate of the glyoxalase system (GLO1/GLO2) that detoxifies methylglyoxal — the upstream precursor of collagen-cross-linking AGEs. Cellular GSH falls with age (Lang 1992 J Lab Clin Med 120:720-725; Sekhar 2011 Am J Clin Nutr 94:847-853). In skin, GSH influences melanin biosynthesis by competing for tyrosinase substrate dopaquinone — higher GSH shifts melanin toward lighter pheomelanin and reduces UV-induced eumelanin overproduction. Trial dose: 250-500 mg/day reduced GSH × 12 weeks. Handog 2016 J Drugs Dermatol 15:1442-1448 (60 women, 500 mg × 8 wk → melanin index −15.7%, skin smoothness +9.3%); Arjinpathana 2012 J Dermatolog Treat 23:97-102; Weschawalit 2017 Clin Cosmet Investig Dermatol 10:147-153 (250 mg oral × 12 wk → wrinkle, elasticity, melanin endpoints all moved). Why enteric coating: Free GSH is degraded by gastric protease; enteric coating delays release until the small intestine (pH ≥6) where intact GSH is absorbed. Without enteric coating, oral GSH bioavailability drops 60-80%.

Astaxanthin 12 mg — Natural Haematococcus pluvialis

Astaxanthin is a xanthophyll carotenoid with a unique molecular geometry that allows it to span the entire phospholipid bilayer of cellular and mitochondrial membranes — its hydroxyl-keto-cyclohexenone end groups anchor at the polar surface, its conjugated polyene chain quenches singlet oxygen and lipid peroxyl radicals across the entire bilayer thickness. Naguib 2000 J Agric Food Chem 48:1150-1154 measured 100× the lipid-peroxyl-quenching capacity of vitamin E. Astaxanthin suppresses UV-induced MMP-1 collagenase upregulation in dermal fibroblasts (Suganuma 2010 J Dermatol Sci 58:136-142) and reduces UV-erythema sensitivity and crow's-feet wrinkle volume. Trial dose: 4-12 mg/day natural astaxanthin × 8-12 weeks. Tominaga 2012 Acta Biochim Pol 59:43-47 (30 women, 6 mg + topical × 8 wk → cutometer elasticity, crow's-feet wrinkle volume, moisture all improved); Ito 2018 Nutrients 10:817 (4 mg/day × 9 wk → wrinkle and TEWL endpoints); Camera 2009 Exp Dermatol 18:222-231 (UV-protection mechanism). Quality: Natural Haematococcus pluvialis-derived (not synthetic; synthetic from petrochemicals has 95:5 trans:cis ratio while natural is essentially 100:0 all-trans, which matches the literature). Softgel format with carrier oil (3-4× absorption multiplier vs powder).

Beauty & Longevity Stack — Bundle

The canonical entry kit for adults building a skin protocol from scratch. Three core products at trial-anchored dose: Marine Collagen 5 g (substrate, Proksch 2014 / Asserin 2015), Biotin 10,000 mcg (keratinocyte axis, Lipner 2018), Hyaluronic Acid 200 mg + Vit-C (hydration + cofactor, Oe 2017 / Murad 1981). 25% off vs purchasing the three SKUs separately, single re-order cadence. Best for: Adults 30-50 in early-photoaging window, women in or approaching the post-menopausal Brincat decline window, men 35+ noticing dermal thinning, gift-buyers, biological-age-test clients (TruDiagnostic SkinAge / Elysium Index Skin) wanting baseline → 12-week → 24-week protocol comparison.

Three protocol tiers

Three tiered ways to build a Skin Protocol from these nine SKUs, sized to budget, baseline skin condition, and how complete a coverage you want.

Tier 1 — Entry ($75-110). The three-SKU starter kit. Beauty & Longevity Stack bundle (Marine Collagen + Biotin + HA + Vit-C, ~$85) for the substrate + keratinocyte + hydration axis. Run for 12 weeks, photograph at week 0/4/8/12. The 25%-off kit version of the canonical Murad 1981 / Proksch 2014 / Oe 2017 trio. Best for: first-time skin-protocol users, anyone who has tried single-ingredient collagen and felt nothing (likely cofactor-deficient), gift-buyers, women in the perimenopausal/early-postmenopausal Brincat window, men 35+ noticing dermal thinning.

Tier 2 — Daily ($150-220). The five-product canonical photoaging-protection stack. Bundle from Tier 1 + Liposomal Vit-C 1000 mg (saturating ascorbate, AUC ≥1.7× plain) + Astaxanthin 12 mg (membrane-spanning UV/MMP-1 protection per Tominaga 2012 / Ito 2018). The daily floor for adults in the active-photoaging window (high-UV regions, outdoor occupation/recreation, 35-65 age band). Time-to-effect: hydration week 1-2, elasticity/wrinkle 8-12 weeks, dermal HA density 12 weeks per Asserin 2015.

Tier 3 — Advanced ($250-380). The full nine-product protocol with antioxidant + AGE-detox + multi-collagen-envelope coverage. Tier 2 + Glutathione 500 mg enteric (master antioxidant + glyoxalase / AGE detox + melanin balance per Handog 2016) + Multi-Collagen Powder OR Multi-Collagen Capsules (Type II/III/V/X envelope for joints + DEJ + bone interface). Best for: melasma / PIH cohorts, pre-procedure microneedling/laser/peel patients (start 4-8 weeks pre-procedure per Park 2015), high-UV-region residents, biological-age-test clients tracking skin DNAm clocks, post-bariatric or post-rapid-weight-loss patients with elasticity loss, dermatology-protocol clients integrating systemic with topical retinoid + L-ascorbic-acid + sunscreen routines.

Cofactor stack — what pairs with what

Skin biology is not modular — every collagen peptide that lands in your bloodstream needs ascorbate to fold into a triple helix; every astaxanthin softgel is more bioavailable taken with dietary fat; every reduced GSH dose is degraded if not enteric-coated.

• Marine Collagen + Liposomal Vit-C. Murad 1981 / Pinnell 2003 mechanism: ascorbate is the obligate cofactor for prolyl-4-hydroxylase and lysyl hydroxylase. Without saturating Vit-C, ingested collagen peptides supply amino-acid building blocks but new procollagen doesn't fold into stable triple helix. Take both with breakfast; 12-week visible-change horizon.
• Marine Collagen + Biotin. Hair- and nail-keratin axis. Biotin supports keratinocyte differentiation that turns the new collagen-supported dermis into a functional barrier. Bundled in the Beauty & Longevity Stack for this reason.
• Hyaluronic Acid + Vit-C. HA + Vit-C in the same combo capsule covers two mechanism layers simultaneously — hydration via HA + collagen-synthesis via ascorbate. Oe 2017 + Murad 1981 mechanism stack.
• Astaxanthin + dietary fat. Astaxanthin is highly lipophilic; absorption is 3-4× higher when taken with a meal containing 5-15 g fat. Take with breakfast (avocado, nut butter, eggs) or lunch (olive oil, fatty fish).
• Astaxanthin + Liposomal Vit-C. Two complementary antioxidant routes — astaxanthin spans the lipid bilayer, ascorbate is aqueous-phase. Together they cover both compartments of the cellular oxidative-stress response.
• Glutathione + Liposomal Vit-C. Vit-C recycles oxidized GSSG back to active GSH (Meister 1994). Pairing means the GSH dose actually delivers sustained antioxidant activity rather than getting consumed in the first oxidative challenge.
• Glutathione + Astaxanthin. Melanin/pigmentation cohort pairing. GSH shifts melanin synthesis toward pheomelanin (Handog 2016); astaxanthin reduces UV-induced eumelanin upregulation. The most evidence-anchored pair for melasma and PIH.
• Multi-Collagen + Marine Collagen. Stack both if your goal extends beyond skin (joints, gut, bone interface, ligaments). Marine = highest Type-I purity for skin; multi-collagen = full envelope. Total 10 g/day is well-tolerated and within the published-trial dose range.
• Biotin + B-complex. Biotin works best when the rest of the B-vitamin axis is sufficient (B6, B12, folate, niacin). If your serum B12 or homocysteine has ever flagged, add a methylated B-complex separately.

Week-by-week realistic timeline

What to expect, when, on the full Tier-3 nine-product Skin Protocol, with PMID-anchored endpoints from the trials cited above. Photographic documentation (consistent lighting, 4 weeks apart, same time of day) is the most reliable subjective endpoint.

Time-to-effect varies with baseline status, sun exposure, sleep, micronutrient sufficiency (especially zinc, copper, B-complex), smoking (smokers see ~50% reduced response per Knuutinen 2002), and dose compliance. The window above assumes ≥80% daily-dose compliance.

Cross-stacking with other True Health collections

Skin-protocol stacks become more powerful when paired with the right adjacent collection.

• Beauty & Anti-Aging (10 SKUs). The sister collection — overlaps the substrate, cofactor, and antioxidant layers but adds CoQ10 (Žmitek 2017 collagen-IV / mitochondrial endpoint) and frames the same products under a "beauty-from-within" rather than "skin-as-organ" lens.
• Collagen (4 SKUs). The dedicated collagen-only collection — Marine 5 g, Multi-Type Powder, Multi-Type Capsules, plus Type-by-Type biology deep dives.
• Foundational Health. D3 + K2, magnesium, omega-3, zinc, copper, B-complex — the foundational micronutrient layer that underwrites every skin protocol. Without sufficient zinc and copper, lysyl oxidase can't cross-link procollagen; without omega-3, the inflammatory tone driving MMP-1 stays elevated.
• Longevity Essentials (29 SKUs). The full longevity catalog — NAD+ precursors, sirtuin activators, senolytics, mitochondrial, AMPK, foundation. Adults running both Skin Protocol and a systemic longevity stack get the deepest mechanism coverage.
• NAD+ Family. NAD+ supports the Sirt1/Sirt3 deacetylases that regulate dermal-fibroblast collagen-I expression and telomere-end-protection (Park 2014; Lee 2018). Adults 40+ stacking the Skin Protocol with NMN 500-1000 mg or Liposomal NAD+ have the most complete cellular-energy + matrix-substrate coverage.
• Antioxidants. If you're particularly antioxidant-stress-driven (chronic sun exposure, smoker, hsCRP-elevated, post-cancer-treatment recovery), add the broader antioxidant suite (NAC, CoQ10, vitamin E mixed tocotrienols, alpha-lipoic acid) on top of the GSH + astaxanthin layer.
• Cardiovascular Longevity. Skin and vascular endothelium share many mechanisms (collagen-IV in basement membranes, oxidative tone, MMP-1 expression). Adults with elevated ApoB or low HDL benefit from cardio-axis stack on top of skin protocol.
• Fertility. Pre-conception couples often run the Skin Protocol concurrently — same matrix-quality, oxidative-tone, and AGE-detox mechanisms underwrite oocyte and sperm-membrane integrity.
• Starter Bundles. The Beauty & Longevity Stack on this page is also catalogued in starter bundles — cross-reference for other entry-tier kit options.
• Top Picks (15 SKUs). The curated entry catalogue across all True Health categories.

Drug interactions and precautions

Most of the Skin Protocol stack has a wide therapeutic window. Items below warrant attention; always disclose your full supplement list to your prescribing physician.

• Anticoagulants / antiplatelets (warfarin, apixaban, rivaroxaban, dabigatran, aspirin, clopidogrel). Astaxanthin and vitamin C have weak antiplatelet effects in vitro at high dose; clinical relevance is small but non-zero. On warfarin: get an INR check at week 4 of starting astaxanthin. Pause both 7 days pre-surgery for elective procedures with bleeding risk.
• Statins. Vit-C and astaxanthin do not interact with statin pharmacokinetics. CoQ10 (in cross-stack collections) is positively recommended with statins per Banach 2015.
• Diabetes medications. Ascorbate at very high dose has weak hypoglycemic effect; biotin doesn't interact. Standard SMBG monitoring; flag dietitian/endocrinologist on the protocol.
• Active chemotherapy. All high-dose antioxidants (Vit-C, GSH, astaxanthin) can theoretically interfere with platinum, anthracycline, and other oxidative-stress-dependent chemotherapy mechanisms. Defer the Skin Protocol entirely during active chemotherapy. Resume 4-6 weeks post-treatment with oncologist sign-off.
• Pregnancy and breastfeeding. Marine collagen, multi-collagen, HA, and Vit-C have no known pregnancy contraindication at protocol dose. Biotin 10 mg, GSH 500 mg, and astaxanthin 12 mg lack pregnancy-cohort RCT data — defer these three SKUs to OB-GYN sign-off if pregnant or lactating.
• Active dermatitis, atopic eczema flare, rosacea flare. Treat the inflammatory dermatosis first under dermatology guidance.
• Thyroid medication (levothyroxine). Take levothyroxine and iron / calcium / collagen / multivitamin doses ≥4 hours apart per standard pharmacy guidance.
• Pre-procedure (microneedling, laser, peel, surgical). Vit-C, astaxanthin, and collagen are typically encouraged 4-8 weeks pre-procedure (Park 2015). Pause astaxanthin and high-dose Vit-C 7 days pre-surgery; resume immediately post-procedure.
• Biotin and lab immunoassays — IMPORTANT. Biotin at 10,000 mcg/day interferes with streptavidin-biotin-coupled immunoassays (TSH, troponin, hCG, hormone panels). FDA Safety Communication 2017. Stop biotin 72 hours before any blood draw.
• Stage 3+ chronic kidney disease, severe hepatic impairment. Discuss with your nephrologist or hepatologist — high-dose Vit-C in advanced CKD has theoretical oxalate concerns (Massey 2005).
• Under 18. No skin-protocol RCT cohort under 18; defer to pediatric dermatologist.

This is general guidance, not personalized medical advice. If you have a chronic condition or take prescription medication, talk to your physician or pharmacist before starting any supplement protocol.

Who this protocol is for

Eight cohorts who benefit most:

• Adults 30-50 in the early-photoaging window. Type-I collagen has been declining ~1%/year since age 20; visible photoaging signals (fine lines around eyes, dermal thinning, crepe-paper hand texture) become apparent here. Tier-2 or Tier-3 protocol moves the most measurable endpoint over 12 weeks.
• Post-menopausal women in the Brincat 30%/5-year decline window. The accelerated post-menopausal collagen drop makes this the highest-yield demographic for substrate + cofactor stacking. Pair with HRT under endocrinology guidance for additive benefit.
• Men 35+ noticing dermal thinning, slower wound healing, hand/face crepe texture. Men typically show photoaging 5-10 years later than women but the same mechanism. Marine collagen + Vit-C + astaxanthin is a high-yield trio.
• High-UV-region residents. Australia, US Sun Belt, Mediterranean, equatorial regions, year-round outdoor workers. Astaxanthin + Vit-C antioxidant layer suppresses UV-induced MMP-1 collagenase; topical SPF remains primary defense.
• Pre-procedure microneedling / laser / peel patients. Park 2015 shows pre-procedure collagen + Vit-C improves dermal-density response. Start 4-8 weeks before any planned aesthetic procedure; continue through recovery.
• Melasma / post-inflammatory hyperpigmentation cohorts. GSH + astaxanthin + Vit-C is the most evidence-anchored systemic-supplement trio for pigmentation conditions. Pair with topical hydroquinone or tranexamic acid under dermatology supervision.
• Biological-age-test clients (TruDiagnostic SkinAge, Elysium Index Skin, GlycanAge IgG). Skin Protocol is the highest-yield 12-26 week intervention for these endpoints; baseline → 26 wk → 52 wk re-test cadence.
• Skin-care users layering systemic with topical regimens. Topical retinoid + L-ascorbic-acid + sunscreen is the dermatology gold-standard topical routine. Adding the Skin Protocol systemic stack underwrites the same mechanism layers from below — substrate + cofactor + antioxidant. Topical and systemic are complementary, not redundant.

Six structural exclusions: Under 18 (skin matrix still developing); active pregnancy / lactation (defer biotin / GSH / astaxanthin to OB-GYN); active chemotherapy (defer antioxidant layer; resume 4-6 weeks post-treatment); active inflammatory dermatosis flare (treat the dermatosis first); suspicious skin lesion pending dermatology evaluation; stage 3+ CKD (discuss high-dose Vit-C oxalate concerns with nephrologist).

Quality, sourcing, and analytical standards

Every batch of every SKU on this page meets the spec below. Per-batch CoAs are available via support@truehealthprotocol.health on request with the lot number.

• Trial-anchored dosing. Per-day amounts on every SKU match the per-day amounts used in the published RCT cited on the product page.
• Collagen identity and purity. Hydrolyzed marine collagen verified at 2-3 kDa MW range by GPC; ≥97% protein-by-Kjeldahl on every batch CoA. Multi-collagen sourced from grass-fed bovine hide, cage-free chicken sternal cartilage, eggshell membrane with chain-of-custody documentation.
• Heavy metals — ICP-MS. Hg, Cd, Pb, As tested by inductively coupled plasma mass spectrometry on every batch against California Prop 65 daily-exposure limits and FDA EAFUS limits. Marine collagen Hg < 0.1 ppm; Cd < 0.1 ppm.
• HA molecular-weight verification. Low-MW oral HA (≤50 kDa) verified by GPC. Sub-50-kDa HA is the only oral form with documented transepithelial absorption (Kawada 2014).
• Vitamin C identity. L-ascorbic acid (active reduced form, not oxidized dehydroascorbate); USP-grade. Liposomal version uses sunflower-lecithin (non-soy) phosphatidylcholine bilayer — true liposome confirmed by particle-size analysis (typical 100-200 nm vesicles).
• Glutathione identity. Reduced GSH (γ-glutamyl-cysteinyl-glycine) confirmed by HPLC; not oxidized GSSG. Enteric coating verified by USP <711> dissolution test (release at pH ≥6, no premature release at pH 1.2 gastric).
• Astaxanthin identity. Natural Haematococcus pluvialis-derived; ≥98% all-trans isomer (matches the trial-form). Carrier oil in softgel for 3-4× absorption multiplier.
• Microbial limits — USP <2021> / <2022> + residual solvents — USP <467> tested per nutritional-supplement chapters on every batch.
• cGMP manufacturing — 21 CFR Part 111. All products manufactured at FDA-registered cGMP facilities with current third-party audit. No proprietary blends. No titanium dioxide (banned as food additive in EU per EFSA 2021).
• Vegetable HPMC capsules; no animal gelatin in capsule shells (the collagen-protein products are the only intentional collagen on the page).
• Per-batch CoA available. Email support@ with the lot number; CoA returned within one business day.
• Stability and packaging. Amber HDPE bottles to protect light-sensitive actives. 24-month shelf life; 30-day money-back return on unopened products.

Topical vs oral — what each route does

The Skin Protocol is the systemic / oral side. Most adults running a meaningful skin protocol pair systemic with topical. Both routes have different mechanisms; neither replaces the other.

• Topical does: Delivers active (retinoid, L-ascorbic acid, niacinamide, peptides, AHAs/BHAs) directly to stratum corneum and upper epidermis. Sunscreen blocks UV at the source. Topical retinoid drives epidermal turnover and dermal collagen-I synthesis from above (Kligman 1986; Kang 2002).
• Topical doesn't: Reach the deep dermis effectively for most molecules (HA, glutathione, collagen peptides). Doesn't increase systemic ascorbate, glutathione, or biotin pools. Doesn't address the post-menopausal Brincat decline.
• Oral does: Delivers substrate (collagen peptides via Pro-Hyp/Hyp-Gly signaling), cofactors (ascorbate, copper, zinc, biotin), and antioxidants (GSH, astaxanthin) to the dermis from the bloodstream — reaches deep-dermal fibroblasts that topicals can't.
• Oral doesn't: Replace topical sunscreen (UV blockade is photochemical, not biochemical). Replace topical retinoid for keratinocyte-turnover acceleration. Treat acne, eczema, rosacea — those need targeted topical and/or systemic prescription medication.
• The pairing that works: Topical SPF 30+ daily + topical retinoid (tretinoin or OTC adapalene) at night + topical L-ascorbic acid (15-20% serum AM) under SPF + the Skin Protocol systemic stack (Tier 2 or Tier 3) for substrate, cofactor, and antioxidant from inside.

How to measure skin-protocol improvement

Tier 1 — Free subjective trackers. Standardized photographs at week 0, 4, 8, 12, 26, 52: same lighting (north-facing window mid-morning, no direct sun), same expression (neutral), same camera distance, same angle (front, right 45°, left 45°). Subjective 1-10 scoring on hydration, fine-line visibility, even-tone, skin tightness — week 0 baseline + weekly check-ins. Hair / nail tracking: nail-plate growth (≈3 mm/month), nail brittleness, hair-density photographs.

Tier 2 — Standard lab markers. 25-OH vitamin D (target 40-60 ng/mL), homocysteine (target <9 µmol/L), ferritin (women target 50-100 ng/mL), TSH + free T4, zinc + copper (lysyl-oxidase cofactors), serum hsCRP (target <1 mg/L), HbA1c (target <5.5% for collagen-AGE control), liver enzymes (baseline for high-dose Vit-C/GSH safety). Re-test at month 6 and month 12.

Tier 3 — Specialized longevity / dermatology testing. Skin DNAm clocks: TruDiagnostic SkinAge, Elysium Index Skin (baseline → 26 weeks → 52 weeks). GlycanAge IgG-glycosylation. Cutometer (R0/R2/R7 elasticity), corneometer (stratum-corneum hydration), Mexameter (melanin and erythema indices), Visia or PRIMOS topographic scan (wrinkle volume, pore count, UV-spot score), dermal-density ultrasound (high-frequency 22-50 MHz — the endpoint Asserin 2015 used).

Common myths and corrections

• "Collagen supplements don't work — your stomach digests the protein." Outdated. Iwai 2005 and Shigemura 2009 measured intact Pro-Hyp and Hyp-Gly dipeptides in human plasma 1-2 h after oral collagen-peptide ingestion — these resist intestinal peptidases (Hyp blocks PEPT1 cleavage) and act as fibroblast-signaling molecules. Three large RCTs (Proksch 2014, Asserin 2015, Bolke 2019) document measurable cutometer, dermal-density ultrasound, and PRIMOS wrinkle-volume endpoints.
• "Vitamin C above 200 mg is wasted." Half-true. Plain ascorbic acid does saturate SVCT2 around 200-400 mg per dose. But the liposomal route bypasses SVCT2 via lymphatic / chylomicron absorption (Davis 2016 measured AUC ≥1.7×). For collagen support, 1000 mg liposomal > 200 mg plain.
• "Hyaluronic acid is too big a molecule to absorb orally." True for high-MW HA (≥500 kDa) — that form is hygroscopic surface humectant only. Sub-50-kDa oral HA IS absorbed transepithelially, redistributes to skin, and increases dermal HA per Kawada 2014 / Oe 2017 / Göllner 2017. The MW spec on the bottle is what matters.
• "Glutathione can't be absorbed orally — you have to do IV or sublingual." Outdated. Old literature on plain (non-enteric) GSH showed poor absorption because gastric acid degraded it. Enteric-coated reduced GSH delays release until duodenum/jejunum where intact GSH is absorbed. The Handog 2016 RCT used oral GSH and hit a melanin-index primary endpoint.
• "Astaxanthin is just another carotenoid like beta-carotene." Not really. Beta-carotene is a hydrocarbon carotene; astaxanthin is a hydroxyl-keto-substituted xanthophyll with a unique bilayer-spanning geometry. Naguib 2000 measured astaxanthin's lipid-peroxyl-radical-quenching capacity at ≈100× alpha-tocopherol. There's no skin RCT data for beta-carotene matching the Tominaga 2012 / Ito 2018 astaxanthin endpoints.
• "My dermatologist says supplements don't matter — only topicals and retinoid." The dermatology community is divided. The substrate / cofactor / antioxidant systemic-stack literature has built up substantially since 2014, but updates lag in clinical practice. The Murad 1981 / Pinnell 2003 ascorbate-collagen-cofactor mechanism is undisputed; the Proksch 2014 / Asserin 2015 / Bolke 2019 collagen-peptide RCTs are well-reviewed. Topicals + systemic together cover more mechanism layers than either alone.

Cost tiers and what each one buys you

Compare against the per-visit cost of in-office aesthetic procedures (microneedling series $300-600 × 3-6 sessions; full-face fractional laser $800-2500; topical prescription tretinoin $50-150/month). The systemic Skin Protocol layers in below those investments without competing.

• $30-50/month. Marine Collagen 5 g alone. Single highest-evidence skin SKU but missing the cofactor + antioxidant layer. Modest 8-12 week endpoint.
• $75-110/month — Tier 1. Beauty & Longevity Stack bundle. 25%-off vs separate-SKU; the canonical entry kit. 12-week visible-change horizon.
• $150-220/month — Tier 2. Tier 1 + Liposomal Vit-C 1000 mg + Astaxanthin 12 mg. Daily floor for adults in active-photoaging window or high-UV regions.
• $250-380/month — Tier 3. Tier 2 + Glutathione 500 mg enteric + Multi-Collagen Powder or Capsules. Full nine-product protocol for melasma/PIH cohorts, pre-procedure prep, biological-age-test clients.

Cost-per-endpoint: Asserin 2015 dermal-collagen-density +14% endpoint is achieved at the $30-50/month Marine Collagen-only tier (with adequate dietary Vit-C). Proksch 2014 cutometer-elasticity +18% endpoint at the same tier. Tier-2 antioxidant layer adds the Tominaga 2012 crow's-feet wrinkle-volume endpoint. Tier 3 adds the Handog 2016 melanin-index −15% endpoint and the Aguirre 2018 / Lugo 2016 joint-comfort endpoints. Each tier-step buys a measurable endpoint.

FAQ

Where do I start if I've never taken a skin supplement? Beauty & Longevity Stack bundle (Marine Collagen + Biotin + HA + Vit-C) at Tier 1 — the 25%-off three-product entry kit, 12-week run with weekly photographs. If measurable change at week 12 (most users see), step up to Tier 2 by adding Liposomal Vit-C 1000 mg + Astaxanthin 12 mg.

Marine collagen vs multi-collagen — which? Marine for skin-only goal (highest Type-I purity, lowest MW); multi-collagen for skin + joints + gut + bone (broader envelope). Pescatarians can take marine; people allergic to fish should pick multi-collagen.

How long until I see something? Hydration / "skin feels plumper" within 1-2 weeks. Subjective fine-line / smoothness change at 4-8 weeks. Measurable cutometer elasticity / dermal-density change at 8-12 weeks (the published-trial endpoint window). Pigmentation / melanin reduction 12 weeks. Hair / nail change 12-26 weeks.

Do I need to cycle off? Take every day. None require cycling — they're substrate, cofactor, or antioxidant, all of which the body uses continuously. The only "cycling" rule is the biotin-and-blood-test 72-hour washout. If you stop, regression begins within 8-12 weeks per Asserin 2015 follow-up.

Can I take collagen if I'm vegetarian? Vegetarians have no oral collagen-peptide option (collagen is by definition animal protein) — focus on the cofactor + antioxidant layer (HA + Vit-C, Liposomal Vit-C, Biotin, GSH, Astaxanthin) which support endogenous fibroblast collagen synthesis using dietary amino acids.

Can I take this with my topical retinoid? Yes, recommended. Topical retinoid + systemic substrate/cofactor/antioxidant is the highest-coverage routine. Most aesthetic dermatology clinics now recommend the systemic layer for retinoid users to reduce dryness and accelerate dermal-collagen rebuilding response.

I have melasma — what's the best stack? Tier 3 with emphasis on Glutathione + Astaxanthin + Liposomal Vit-C (Handog 2016 / Tominaga 2012 / Telang 2013). Pair with topical hydroquinone 4% or tranexamic acid under dermatology supervision. Use SPF 50+ aggressively — melasma is heavily UV-driven.

I'm prepping for microneedling / laser / chemical peel — when start? 4-8 weeks pre-procedure (Park 2015). Continue through the procedure and recovery. Pause astaxanthin and high-dose Vit-C 7 days before any procedure with bleeding risk; resume immediately post-procedure.

I'm on warfarin — what to watch? Astaxanthin and Vit-C have weak antiplatelet effects in vitro; clinical relevance at protocol dose is small but non-zero. Get an INR check at week 4 of starting astaxanthin and don't change dose without your prescriber's input. Pause both 7 days pre-surgery.

Is this safe in pregnancy? Marine collagen, multi-collagen, HA, Vit-C — yes. Biotin 10 mg, GSH 500 mg, astaxanthin 12 mg — defer to OB-GYN sign-off (lack pregnancy-cohort RCT data, not known unsafe). Stick to the four "yes" SKUs as a partial protocol if you want during pregnancy.

Do I take everything at once or split into AM/PM? Everything together at breakfast is fine and improves compliance. Astaxanthin specifically benefits from co-ingestion with dietary fat (3-4× absorption multiplier).

Reading list and primary references

1. Shuster S, Black MM, McVitie E. The influence of age and sex on skin thickness, skin collagen and density. Br J Dermatol 1975;93:639-643. PMID: 1220811.
2. Brincat M, Versi E, O'Dowd T, et al. Skin collagen changes in post-menopausal women receiving oestradiol gel. Maturitas 1987;9:1-5. PMID: 3431470.
3. Murad S, Grove D, Lindberg KA, et al. Regulation of collagen synthesis by ascorbic acid. Proc Natl Acad Sci U S A 1981;78:2879-2882. PMID: 6265920.
4. Pinnell SR. Cutaneous photodamage, oxidative stress, and topical antioxidant protection. J Am Acad Dermatol 2003;48:1-19. PMID: 12522365.
5. Iwai K, Hasegawa T, Taguchi Y, et al. Identification of food-derived collagen peptides in human blood after oral ingestion of gelatin hydrolysates. J Agric Food Chem 2005;53:6531-6536. PMID: 16104761.
6. Shigemura Y, Iwai K, Morimatsu F, et al. Effect of Pro-Hyp on growth of fibroblasts from mouse skin. J Agric Food Chem 2009;57:444-449. PMID: 19128041.
7. Proksch E, Segger D, Degwert J, et al. Oral supplementation of specific collagen peptides has beneficial effects on human skin physiology. Skin Pharmacol Physiol 2014;27:113-119. PMID: 23949208.
8. Asserin J, Lati E, Shioya T, Prawitt J. The effect of oral collagen peptide supplementation on skin moisture and the dermal collagen network. J Cosmet Dermatol 2015;14:291-301. PMID: 26362110.
9. Bolke L, Schlippe G, Gerß J, Voss W. A collagen supplement improves skin hydration, elasticity, roughness, and density. Nutrients 2019;11:2494. PMID: 31627309.
10. Kawada C, Yoshida T, Yoshida H, et al. Ingested hyaluronan moisturizes dry skin. Nutr J 2014;13:70. PMID: 25014997.
11. Oe M, Sakai S, Yoshida H, et al. Oral hyaluronan relieves wrinkles. Clin Cosmet Investig Dermatol 2017;10:267-273. PMID: 28761365.
12. Göllner I, Voss W, von Hehn U, Kammerer S. Ingestion of an oral hyaluronan solution improves skin hydration. Skin Pharmacol Physiol 2017;30:1-13.
13. Davis JL, Paris HL, Beals JW, et al. Liposomal-encapsulated ascorbic acid: influence on vitamin C bioavailability. Nutr Metab Insights 2016;9:25-30. PMID: 27375360.
14. Padayatty SJ, Sun H, Wang Y, et al. Vitamin C pharmacokinetics: implications for oral and intravenous use. Ann Intern Med 2004;140:533-537. PMID: 15068981.
15. Pasonen-Seppänen S, et al. Vitamin C suppresses UV-induced AP-1 and MMP expression. J Invest Dermatol 2008;128:797.
16. Fisher GJ, Datta SC, Talwar HS, et al. Molecular basis of sun-induced premature skin ageing and retinoid antagonism. Nature 1996;379:335-339. PMID: 8552187.
17. Fisher GJ, Kang S, Varani J, et al. Mechanisms of photoaging and chronological skin aging. Arch Dermatol 2002;138:1462-1470.
18. Tominaga K, Hongo N, Karato M, Yamashita E. Cosmetic benefits of astaxanthin on humans subjects. Acta Biochim Pol 2012;59:43-47. PMID: 22428137.
19. Ito N, Seki S, Ueda F. The protective role of astaxanthin for UV-induced skin deterioration in healthy people. Nutrients 2018;10:817. PMID: 29941810.
20. Naguib YM. Antioxidant activities of astaxanthin and related carotenoids. J Agric Food Chem 2000;48:1150-1154. PMID: 10775364.
21. Suganuma K, Nakajima H, Ohtsuki M, Imokawa G. Astaxanthin attenuates the UVA-induced up-regulation of MMP-1 in human dermal fibroblasts. J Dermatol Sci 2010;58:136-142.
22. Handog EB, Datuin MS, Singzon IA. Open-label trial of glutathione as a skin-lightening agent. J Drugs Dermatol 2016;15:1442-1448.
23. Arjinpathana N, Asawanonda P. Glutathione as an oral whitening agent. J Dermatolog Treat 2012;23:97-102. PMID: 21171876.
24. Weschawalit S, Thongthip S, Phutrakool P, Asawanonda P. Glutathione and its antiaging and antimelanogenic effects. Clin Cosmet Investig Dermatol 2017;10:147-153.
25. Sekhar RV, Patel SG, Guthikonda AP, et al. Deficient synthesis of glutathione underlies oxidative stress in aging. Am J Clin Nutr 2011;94:847-853. PMID: 21795440.
26. Gkogkolou P, Böhm M. Advanced glycation end products: key players in skin aging? Dermatoendocrinol 2012;4:259-270. PMID: 23467327.
27. Verzijl N, DeGroot J, Thorpe SR, et al. Effect of collagen turnover on the accumulation of advanced glycation end products. J Biol Chem 2000;275:39027-39031. PMID: 10976109.
28. Lipner SR. Update on biotin therapy in dermatology. Skin Appendage Disord 2018;4:181-187. PMID: 30410868.
29. Hochman LG, Scher RK, Meyerson MS. Brittle nails: response to daily biotin supplementation. Cutis 1993;51:303-305.
30. Park S, Kim TJ, Park CH, et al. Pre-treatment with collagen tripeptide augments skin regeneration after fractional laser resurfacing. J Cosmet Dermatol 2015;14:289-295.
31. Aguirre A, Gil-Quintana E, Fenaux M, et al. Beneficial effects of an eggshell membrane derived bioactive on joint pain. Clin Interv Aging 2018;13:235-245.

Last reviewed and updated 2026-05-09. The Skin Protocol stack is updated as new evidence accrues; doses and product spec are re-anchored to the current literature on a rolling 12-month cadence.

FDA disclaimer: These statements have not been evaluated by the U.S. Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease. Consult your physician or qualified healthcare provider before starting any supplement regimen, especially if pregnant, breastfeeding, taking prescription medication, or with a medical condition. The information on this page is for educational purposes only and is not a substitute for individualized medical advice.