Skin, hair, nails and body composition. These are the supplement claims people actually buy on, each sorted by how strong the evidence is.
Last reviewed: 27 October 2026 · Works for Us research team · Educational, not medical advice
Beauty supplements are sold on before-and-after photos and manufacturer studies. We grade claims on independent human evidence instead. On that measure most appearance claims land in Tier C, and we say so.
Every tier below comes directly from the evidence grade in our compound summaries. Nothing is upgraded for popularity. If a compound people often ask about isn't graded in our corpus yet, we list it as a gap rather than guess. See how we grade evidence.
Each card tests one claim, not the compound as a whole. So the same compound can be Tier B for skin and Tier C for nails.
This is where the supplement evidence is strongest, which is still not very strong. Two compounds have moderate small-trial support. The rest is marketing.
Claim: Improves skin elasticity and hydration · Moderate evidence
Evidence: Several small randomised trials found measurable improvements in skin elasticity and hydration after 8–12 weeks of hydrolysed collagen.
Caveats: Wrinkle-depth improvements are modest and partly subjective. Trials are small and many are industry-funded.
Collagen peptides: full evidence summaryClaim: Improves skin moisture when taken by mouth · Moderate evidence
Evidence: Small trials of oral hyaluronic acid report positive effects on skin moisture.
Caveats: The trials are small. Applied to the skin, the molecule is too large to 'fill' wrinkles as marketed; it works by hydrating the surface.
Hyaluronic acid (oral): full evidence summaryClaim: Supports wound healing · Moderate evidence
Evidence: Zinc helps wound healing in people who are deficient in it.
Caveats: The benefit is shown in deficient people, not in everyone. Our evidence summary does not yet grade zinc for acne, so it isn't tiered for acne here. Taking more than 40 mg a day long-term risks copper deficiency.
Zinc: full evidence summaryClaim: Improves skin and hair · Weak, mixed or no support
Evidence: The skin and hair claims rest only on studies run by manufacturers.
Caveats: No independent trial supports these claims. Treat the label claims as marketing.
MSM (methylsulfonylmethane): full evidence summaryCondition pages: Skin health · Acne · Eczema · Psoriasis
No supplement in our corpus has graded evidence for regrowing hair. The treatments with evidence are prescription medicines, which belong with a clinician (see below). What we can do is check common claims and worries.
Claim: Causes hair loss (a common worry) · Weak, mixed or no support
Evidence: The worry traces back to a single 2009 study of rugby players. No later study has replicated it.
Caveats: Weak evidence for harm is not proof of no harm. If you are already losing hair, talk to a GP or pharmacist.
Creatine: full evidence summaryAlso relevant: MSM (methylsulfonylmethane) (“improves skin and hair”, Tier C, under Skin); Collagen peptides (“strengthens nails and hair”, Tier C, under Nails).
Condition pages: Hair loss
Nail supplements are a big market with a thin evidence base. Our corpus has no compound with graded support for nail strength.
Claim: Strengthens nails and hair · Weak, mixed or no support
Evidence: The hair and nail claims rest on weak studies run by manufacturers.
Caveats: Unlike its skin evidence (Tier B, above), there is no independent support for hair or nails.
Collagen peptides: full evidence summaryHow your body looks is shaped far more by training, diet and sleep than by anything in a tub. One supplement has strong evidence here, and only alongside training.
Claim: Builds lean mass, combined with resistance training · Strong evidence
Evidence: One of the most-studied supplements. Gains in strength and lean mass alongside training are consistent across trials.
Caveats: It only works alongside training. Early weight gain is water. People with kidney disease should check with a clinician first.
Creatine: full evidence summaryClaim: Helps with fat loss · Weak, mixed or no support
Evidence: Meta-analyses show weight loss of about 1 kg at best, which is trivial.
Caveats: High-dose extracts carry a liver-injury warning (EFSA flagged risk above about 800 mg a day of EGCG, especially when taken on an empty stomach).
Green tea extract (EGCG): full evidence summaryClaim: Helps with weight loss · Weak, mixed or no support
Evidence: Reviews disagree on weight loss: some trials found a small loss and others found none. Its strong evidence is for lowering LDL cholesterol, not weight.
Caveats: Mixed evidence. Buy it for cholesterol or digestion, not as a weight-loss product.
Psyllium husk: full evidence summaryThe best-known treatments for hair loss and acne, such as finasteride, minoxidil, and retinoids like tretinoin, are medicines, not supplements. Whether they suit you is a decision for a clinician or pharmacist, so we don't tier them here. Our prescription pathways guide explains how people access prescription medicines safely in the UK.
Prescription pathways guidePeople ask about these all the time. We haven't tiered them because our corpus doesn't grade them for appearance yet. That is not a verdict either way.
Take any of these? Share your outcome so the next person gets a real answer instead of an advert.
This page is education and evidence review, not medical advice. Works for Us doesn't sell supplements or medicines and has no paid partnerships with any brand. Supplements are regulated as food in the UK, so label claims are not checked the way medicines are. Persistent skin conditions, sudden hair loss and nail changes can signal an underlying health problem. If you notice them, speak to your GP or pharmacist.