Collagen and Biotin Supplements: What the Evidence Shows

Collagen and biotin supplements are heavily marketed for glowing skin and thick hair, but the evidence behind them is much weaker than the advertising suggests. Collagen studies show mixed results, with the best designed and independently funded trials finding no clear benefit, and biotin helps hair and nails mainly in people who are genuinely deficient, which is uncommon.

In India, hair, skin and nail gummies, collagen powders and biotin tablets are now sold everywhere, from pharmacies to social media. Many people take them for months, often alongside other products, without knowing the cause of their hair fall or skin concern. This guide looks at what the research actually shows.

What are collagen supplements supposed to do?

Collagen is the main structural protein in skin. As we age, and especially with sun damage, the amount and quality of collagen in the skin falls, which contributes to wrinkles and sagging. Collagen supplements are usually hydrolysed collagen peptides from fish, cow or pig sources. The idea is that these peptides are absorbed and somehow support the skin’s own collagen production.

What does the research on collagen show?

The results depend on which studies you look at.

Reviews that found some benefit. A 2023 systematic review and meta-analysis in the journal Nutrients pooled 26 randomised trials with 1,721 participants. It found that hydrolysed collagen improved measures of skin hydration and elasticity compared with placebo. However, the authors noted important limitations: many trials were small, products and measurements varied widely, and they called for larger trials to confirm the findings.

A 2025 review that found no reliable benefit. A meta-analysis by Myung and Park in the American Journal of Medicine looked at 23 randomised trials with 1,474 participants. When all trials were pooled, collagen appeared to improve hydration, elasticity and wrinkles. But when the researchers separated the studies:

• Trials that were not funded by companies showed no effect on hydration, elasticity or wrinkles.
• Trials that were funded by companies showed positive effects.
• Higher quality trials showed no significant effect in any category.

The authors concluded that there is currently no clinical evidence to support collagen supplements to prevent or treat skin ageing. Supplement industry groups have disputed this analysis, arguing about how studies were grouped and classified. What is clear is that the evidence is uncertain and not strong enough to justify big promises.

Question	What the evidence suggests
Does collagen improve hydration and elasticity?	Possibly a small effect in some trials, not confirmed in independent, high quality trials
Does collagen reduce wrinkles?	Not convincingly shown
Is it better than sunscreen and a retinoid?	No. Those have much stronger evidence
Is it worth the cost?	A personal decision, but expectations should be modest

What is biotin and who needs it?

Biotin, also called vitamin B7, is a B vitamin found in foods such as eggs, nuts, seeds and some vegetables. True biotin deficiency can cause hair loss, brittle nails and a rash.

A 2017 review in Skin Appendage Disorders looked at the published evidence on biotin for hair loss. The authors found that, outside of pregnancy, malnutrition, certain medicine effects and a rare inherited enzyme deficiency in children, low biotin levels have rarely been reported. All the cases in which biotin helped hair or nails involved an underlying problem. They concluded that there is a lack of evidence for biotin supplementation in healthy individuals.

In other words, if your diet is reasonable and you have no special risk factor, biotin is unlikely to fix your hair fall.

Can biotin cause problems?

Biotin itself is not known to be toxic, but high doses cause an important practical problem: they can interfere with many laboratory blood tests that use biotin in the testing process.

A published case report described a 67 year old patient taking a daily biotin supplement whose blood tests suggested an overactive thyroid, low parathyroid hormone and raised calcium, which raised concern about serious disease. When biotin was stopped, repeat tests a month later were normal. The report notes that biotin can affect:

• Thyroid tests, such as TSH, T3 and T4
• Troponin, a key test used to diagnose heart attacks
• hCG, used in pregnancy tests
• Parathyroid hormone, reproductive hormones, ferritin and some cancer markers

The report also notes that many biotin supplements contain hundreds of times the daily requirement, and that the US Food and Drug Administration had issued a warning about this interference.

Practical advice:

• Tell your doctor and laboratory if you take biotin or any hair, skin and nail supplement, including multivitamins.
• Ask your doctor whether you should stop the supplement before planned blood tests.
• If a test result does not fit how you feel, mention the supplement.

Why might my hair or skin not improve with supplements?

Because supplements do not address the actual cause. Common causes of hair fall include:

• Telogen effluvium, temporary shedding after fever, childbirth, crash diets or stress. DermNet notes that it usually recovers once the trigger is removed.
• Iron deficiency and thyroid problems, which need testing and targeted treatment.
• Pattern hair loss in men and women, which needs specific medical treatment.
• PCOS, which can cause hair thinning along with acne and excess facial hair.

Our guides to hair fall in women and male pattern baldness explain how dermatologists work out the cause.

For skin ageing, the measures with the best evidence are daily sunscreen, a retinoid used carefully, and not smoking. See our sunscreen guide for India and retinol and tretinoin guide.

Are supplements regulated like medicines?

Supplements are generally not tested and approved in the same way as medicines, so their contents, dose and quality can vary between brands. Labels and influencer claims are not proof that a product works. This also applies to other popular skin supplements such as glutathione, which we discuss in our article on glutathione and skin whitening.

Is a good diet enough?

For most healthy people, a balanced Indian diet with enough protein from dal, pulses, milk, curd, paneer, eggs, fish or meat, plus vegetables, fruit, nuts and seeds, provides what the skin and hair need. Supplements may be useful when a doctor has confirmed a specific deficiency, during pregnancy as advised by your obstetrician, or with certain medical conditions.

How should I decide whether to try a supplement?

If you are considering a collagen or biotin product, a few questions help:

• Do I know the cause of my hair or skin concern? If not, find that first.
• Has a doctor found a deficiency? Supplements make most sense when a specific deficiency is confirmed.
• Am I prepared for an uncertain result? With collagen, the best quality evidence does not show a clear benefit.
• Does the cost take money away from proven steps, such as sunscreen or a dermatologist visit?
• Will I remember to tell my doctor about it before blood tests?

If you decide to try one, set a time limit, note how your skin or hair looks before you start, and stop if you see no difference.

When to see a dermatologist

See a dermatologist if:

• Your hair fall has lasted more than a few months, or you see thinning or bald patches
• You have been taking supplements for months without improvement
• You have hair loss with tiredness, irregular periods, weight change or other symptoms
• You want an evidence based plan for ageing skin rather than buying multiple products
• You take biotin and have unexpected blood test results

Supplements are rarely the answer on their own, but finding the real cause often is. Dr. Maria offers online consultations to review your hair or skin concern, the supplements you take, and whether any tests would help.