Supplements Studied for Skin, Hair & Nails

The rationale for combining these four ingredients lies in the sequential and enzymatic nature of structural protein synthesis. Collagen accounts for approximately 70–80% of skin's dry weight and forms the scaffolding around hair follicles and nail matrices. For collagen to be synthesised and properly stabilised, the body requires vitamin C at two critical enzymatic steps. Research by Pullar et al. (Nutrients, 2017) demonstrated that vitamin C participates in collagen hydroxylation reactions that maintain the integrity of the triple-helix structure of mature collagen — without which newly synthesised collagen is unstable and rapidly degraded. A randomised, double-blind, placebo-controlled trial by Proksch et al. (Skin Pharmacology and Physiology, 2014) found that 2.5g of specific collagen peptides daily for eight weeks produced statistically significant improvements in skin elasticity versus placebo. A further study by Hexsel et al. (Journal of Cosmetic Dermatology, 2017) reported that regular intake of bioactive collagen peptides improved nail growth rate and reduced the frequency of nail breakage after 24 weeks of supplementation. Biotin's contribution is primarily to keratin synthesis, the structural protein of hair shafts and nail plates. A comprehensive review by Patel et al. (Skin Appendage Disorders, 2017) identified multiple case reports and small controlled trials showing improved nail strength and hair growth following biotin supplementation, noting that evidence is most robust in individuals with confirmed deficiency or underlying metabolic conditions affecting biotin absorption. Zinc operates across multiple relevant pathways simultaneously. As a cofactor for over 300 enzymes, it supports protein synthesis and cell proliferation within hair follicle bulbs. Zinc deficiency is a recognised cause of telogen effluvium — a form of diffuse hair shedding — and measurement of serum zinc is standard practice in dermatological investigations of unexplained hair loss. At 15mg daily, the zinc dose in this stack sits within the NHS Reference Nutrient Intake range for adults, making excess intake unlikely when dietary sources are considered. Together, these four ingredients address the upstream structural scaffold (collagen peptides), the enzymatic requirements for its stabilisation (vitamin C, zinc), and the keratin integrity of hair and nails (biotin), forming a mechanistically coherent combination.

Individuals seeking additional support may consider orthosilicic acid — a bioavailable form of silicon — which was studied in a 2005 double-blind, placebo-controlled trial by Barel et al. (Archives of Dermatological Research) and found to improve nail quality. Hyaluronic acid supplementation has shown evidence for improving skin hydration in several randomised controlled trials. Omega-3 fatty acids (EPA and DHA) may support skin barrier integrity. Iron deficiency is a common and reversible cause of hair loss in women and should be ruled out by a GP before attributing shedding solely to other nutritional gaps. Individual responses may vary.