Collagen, Biotin and Beauty Supplements: What the Evidence Shows

What this page covers

Beauty supplements promise better skin, hair and nails. This page checks the claims against systematic reviews. It is not a recommendation to take or avoid any product. Evidence labels: established recommendation, promising but limited, mixed, insufficient evidence.

Collagen and skin

Why the difference matters: when funding source and study quality change the answer, the benefit is uncertain. Most participants were women, so results may not apply to everyone. [1] See Supplements for healthy aging for the wider picture and How supplements are regulated.

Biotin for hair, skin and nails

A systematic review concluded that research demonstrating biotin's effect on hair and nail growth is limited. [3] All 18 reported cases that improved had an underlying cause of poor hair or nail growth, and the authors proposed that deficiency and conditions like brittle nail syndrome are uncommon and that evidence is insufficient for supplementation in healthy people. [3] Label: insufficient evidence for healthy people. Hair loss has many causes; see Hair shedding and thinning.

Biotin can interfere with lab tests

Laboratory reviews report that supplemental biotin can distort some immunoassay blood tests. Elevated biotin can falsely raise results in competitive assays and falsely lower them in sandwich assays, which can cause diagnostic errors, most commonly thyroid tests (free T3, free T4 and TSH). [4] Another review lists biotin among interferences that still cause problems in hormone immunoassays. [5] A lab study showed biotin at 200 ng/mL prevented detection of HIV-1 p24 antigen in a point-of-care assay. [6] Tell your clinician and the lab if you take biotin, or any supplement, before blood tests; so they can interpret results. I could not read the FDA's own biotin safety communication for this page, so this section relies on the laboratory reviews above.

Zinc and omega-3

A meta-analysis found zinc treatment reduced inflammatory acne papules, but this does not apply to people without acne, and see Nutrition for skin and hair before taking zinc. [7] For psoriasis, most randomized trials of fish oil showed no significant improvement. [8] Proper evidence not found in the sources checked for omega-3 as a general skin-beauty supplement.

Safety

Supplements can interact with medicines and vary in strength and quality. Read medication interactions and product quality and contamination. Sudden hair loss, patchy loss or scalp scarring needs evaluation rather than a supplement (Alopecia areata and scarring hair loss).