Biotin (vitamin B7): what it does, how much per day and what to know

Short answer: Biotin is vitamin B7 (in the Netherlands, Belgium and France often called vitamin B8, and also known as vitamin H), a water-soluble B vitamin found mainly in eggs, liver, milk, nuts and peanuts. According to the Health Council of the Netherlands, adults need about 40 micrograms a day, and a deficiency is very rare. No upper limit has been set for biotin, but high doses such as 10,000 mcg can interfere with some blood tests, so always tell your doctor or the laboratory that you take biotin.

Last updated: 5 November 2026 · Written by Florian Fermin

Biotin is a well-known vitamin, and at the same time one of the most overhyped, especially when it comes to hair and nails. In this article you will read what biotin is, why it has so many names, what may officially be said about it, how much you need per day and what to look for in a supplement. We sell biotin capsules of 10,000 mcg ourselves. We say that openly, precisely because this article also explains what you should not expect from such a high dose.

What is biotin (vitamin B7, B8 or H)?

Biotin is a water-soluble vitamin from the B group. In English-speaking countries it is usually called vitamin B7, in the Netherlands, Belgium and France vitamin B8, and in Germany often vitamin H. It is the same substance everywhere.

In food, biotin is free or bound to the amino acid lysine (then it is called biocytin). Supplements usually contain free biotin (Voedingscentrum). D-biotin is on the European list of vitamin forms permitted in food supplements (Directive 2002/46/EC, Annex II). It is not a novel food, and in France it is also on the official list as a permitted form (Compl'Alim).

What does biotin do?

The European Commission has approved these health claims for biotin (Regulation (EU) No 432/2012). They are also the only statements we make about what biotin does:

• Biotin contributes to normal energy-yielding metabolism**
• Biotin contributes to normal functioning of the nervous system**
• Biotin contributes to normal macronutrient metabolism**
• Biotin contributes to normal psychological function**
• Biotin contributes to the maintenance of normal hair**
• Biotin contributes to the maintenance of normal mucous membranes**
• Biotin contributes to the maintenance of normal skin**

The word "maintenance" matters. These claims say that biotin is needed to keep normal hair and normal skin. They do not say that extra biotin makes your hair grow faster or thicker.

How much biotin do you need per day?

Adults need about 40 micrograms (µg or mcg) of biotin a day. That is an adequate intake set by the Health Council of the Netherlands: there is too little data for a firm requirement. According to the Voedingscentrum, you get enough biotin from ordinary food.

For comparison: one capsule of our biotin capsules contains 10,000 mcg (10 mg) of biotin. That is 20,000% of the reference intake, or 200 times as much. The label says: 1 capsule a day with water, preferably during or just after a meal. Do not take more than that.

Which foods contain biotin?

Biotin is found mainly in eggs, liver, milk, nuts and peanuts (Voedingscentrum). If you eat a varied diet, you usually get the 40 micrograms a day from your food.

One exception is raw egg white. It contains avidin, a protein that binds biotin so your body cannot absorb it. If you boil or fry an egg, avidin no longer does any harm. According to the Voedingscentrum, a biotin deficiency occurs almost only in people who eat a lot of raw eggs.

Does biotin help hair and nails?

There is one approved claim about hair: Biotin contributes to the maintenance of normal hair**. It has not been shown that extra biotin gives more hair growth or stronger nails in healthy people without a deficiency. There is no approved biotin claim for nails.

A 2017 review found 18 described cases in which biotin was used for hair or nail problems. In all cases the people had an underlying problem, such as an inherited or acquired deficiency. The researchers conclude that there is not enough evidence for biotin in healthy people (Patel et al., 2017). If your hair suddenly falls out a lot or your nails break unusually quickly, see your GP. There can be all sorts of reasons behind it, and you will not solve that with a vitamin on a hunch.

Collagen is also often sold together with biotin. There is no approved claim for collagen itself, as we explain in what is collagen. Which nutrients keep coming up in relation to skin, you can read in our article on nutrition and your skin.

Is 10,000 mcg of biotin too much? Side effects and blood tests

No upper limit has been set for biotin, because no harmful effects have been seen at high intakes. The main risk lies elsewhere: high doses can interfere with the results of some laboratory tests. A result can then come out too high or too low.

• EFSA found too little data to set an upper limit. According to the Voedingscentrum, too much biotin is not harmful and you excrete the excess in your urine (EFSA; Voedingscentrum).
• For that reason, the German Federal Institute for Risk Assessment (BfR) does not propose a maximum for biotin in supplements. It does recommend a statement on the packaging that you should tell your doctor or the laboratory staff that you take or recently took biotin. According to the BfR, this can already play a role from about 150 micrograms a day, for example in tests for a heart attack (troponin) and for thyroid values (BfR).
• In a small study, 6 healthy adults took 10 mg of biotin a day for 7 days, exactly the amount in our capsule. Of the 23 tested methods that use biotin, for thyroid hormones, vitamin D and ferritin among others, 9 then gave an abnormal result. Methods without biotin were not affected (Li et al., 2017).

Having a blood test? Always mention that you take biotin. The lab or your doctor can tell you whether and for how long you should stop beforehand. Our label also says: consult your doctor before use if you are pregnant, breastfeeding, taking medication or have a medical condition.

What to look for in biotin capsules

First consider whether you need a supplement at all: most people get enough biotin from their food. If you do choose one, pay attention to these points.

1. Dose. Supplements vary widely, from tens of micrograms to 10,000 mcg a day. A higher dose does not mean it works better, but it does mean a higher chance of disrupted blood tests.
2. Form. Check whether it contains D-biotin or biotin.
3. Ingredients. An honest ingredient list also mentions bulking agents. Our capsules contain biotin, a plant-based HPMC capsule and microcrystalline cellulose as a bulking agent.
4. Vegan or not. HPMC is plant-based, gelatine is not.
5. Price per day. At 1 capsule a day, 60 capsules last 2 months.

If you want to take a look at our capsules, you can buy biotin here. You can also find biotin among our vitamins and minerals and our supplements for skin and hair.

Summary in 3 points

• Biotin is vitamin B7, B8 or H: three names for the same B vitamin. Adults need about 40 micrograms a day, which they usually get from eggs, milk, nuts and peanuts.
• Approved claims include: Biotin contributes to the maintenance of normal hair** and Biotin contributes to the maintenance of normal skin**. Extra hair growth in healthy people has not been shown.
• There is no upper limit, but high doses can interfere with blood tests. Always mention that you take biotin.

Frequently asked questions

Is vitamin B8 the same as vitamin B7?

Yes. Both names refer to biotin. In the Netherlands, Belgium and France B8 is common, internationally B7. Vitamin H is an older name for the same substance.

When should you take biotin?

Our label advises 1 capsule a day with water, preferably during or just after a meal. A fixed time is not necessary.

Should I stop taking biotin before a blood test?

Always tell your doctor or the laboratory that you take biotin. They know which tests are sensitive and whether you should stop for a while beforehand.

Is biotin vegan?

Whether a biotin supplement is vegan depends mainly on the capsule. Our capsules are made of HPMC and are suitable for vegetarians and vegans.

Can I combine biotin with collagen or other B vitamins?

You can. Do keep an eye on how much biotin you get in total, because it is also in many multivitamins, B complexes and hair, skin and nail products.

Sources

1. Voedingscentrum (Netherlands Nutrition Centre). Encyclopaedia: biotin (adequate intake according to the Health Council, food sources, avidin, no upper limit), accessed 5 November 2026. voedingscentrum.nl
2. EFSA NDA Panel. Scientific Opinion on Dietary Reference Values for biotin. EFSA Journal. 2014;12(2):3580. doi:10.2903/j.efsa.2014.3580. doi.org
3. EFSA. Overview on Tolerable Upper Intake Levels as derived by the SCF and the EFSA NDA Panel, version 11, August 2025 (biotin: no upper limit derived). efsa.europa.eu (PDF)
4. BfR. Biotin: Supplemente können Laboruntersuchungen verfälschen (questions and answers), accessed 5 November 2026. bfr.bund.de
5. BfR. Höchstmengenvorschläge für Biotin in Lebensmitteln inklusive Nahrungsergänzungsmitteln (no maximum, but a warning about laboratory tests). bfr.bund.de (PDF)
6. Li D, Radulescu A, Shrestha RT, et al. Non-randomised crossover study in 6 healthy adults, 10 mg biotin a day for 7 days, 37 laboratory tests. JAMA. 2017;318(12):1150-1160. doi:10.1001/jama.2017.13705. doi.org
7. Patel DP, Swink SM, Castelo-Soccio L. Review of 18 published cases of biotin use for hair and nail problems. Skin Appendage Disord. 2017;3(3):166-169. doi:10.1159/000462981. doi.org
8. Regulation (EU) No 432/2012 establishing a list of permitted health claims. eur-lex.europa.eu
9. Regulation (EU) No 1169/2011, Annex XIII (reference intake biotin 50 µg). eur-lex.europa.eu
10. Directive 2002/46/EC on food supplements, Annex II (D-biotin), consolidated version. eur-lex.europa.eu
11. Compl'Alim (French government), ingredient record D-biotin: permitted, accessed 5 November 2026. compl-alim.beta.gouv.fr
12. GOYU, label and product page Biotin (Vitamin B8) Capsules 10,000 mcg (composition, directions and warnings), accessed 5 November 2026.

**Authorised health claim (Regulation (EU) No 432/2012)

This article is for information only and is not medical advice. Food supplements are not a substitute for a varied and balanced diet and a healthy lifestyle. If in doubt, pregnant, taking medication or planning a blood test, talk to your GP or pharmacist.