GuideVitamins

Biotin: Hair Gummies & Blood Tests

Considering a hair, skin and nail gummy? Almost all of them feature biotin, often at 100 times the reference amount or more. Before you add one to your routine, it helps to know what biotin actually does, how much is in a typical product and why your doctor needs to know about it before blood tests.

By the Healthana Editorial Team · Last reviewed: 01 Nov 2026

Daily reference intake (NRV)50 µg a day
Upper limit for adultsNo upper limit set by EFSA; UK guidance: 0.9 mg (900 µg) or less a day from supplements is unlikely to cause harm

What biotin is and what it does

Biotin, also known as vitamin B7 (and sometimes vitamin H), is a water-soluble B vitamin. It works as a helper for enzymes that break down fats, carbohydrates and proteins from food. Biotin is found in many foods, and gut bacteria also make some, so clear shortfalls are uncommon in people eating a varied diet.

Biotin is widely known for its place in hair, skin and nail products. The EU-authorised wordings, including those about hair and skin, are shown in the claims box below. Research on hair has mainly involved people with low biotin levels; evidence that extra biotin changes hair or nails in people who already get enough is limited, so it is worth keeping expectations realistic.

Forms you'll see on labels

FormWhat to know
D-biotinThe form used in virtually all supplements, identical to biotin in food.
Biotin in multivitaminsUsually 25–50 µg, close to the NRV.
Biotin in B complexOften 25–150 µg alongside the other B vitamins.
Hair, skin and nail formulasRange widely, from 150 µg to 5,000 µg or more, usually combined with zinc, selenium and other nutrients.
High-strength biotin (5,000–10,000 µg)Single-nutrient products at 100–200 times the NRV. These are the doses most likely to affect laboratory tests.

How much biotin: NRV, typical amounts and upper limit

  • EU NRV: 50 µg a day.
  • Common supplement amounts: 25–150 µg in multivitamins and B complexes; 150–10,000 µg in hair-focused products.
  • Upper limit: EFSA has not set an upper limit because data were not adequate to derive one. UK guidance says that 0.9 mg (900 µg) or less a day from supplements is unlikely to cause harm.

Biotin is labelled in micrograms; µg and mcg mean the same. Be careful with milligrams: 5 mg is 5,000 µg, or 10,000% NRV.

Food sources include eggs (cooked), liver, salmon, sunflower seeds, almonds, sweet potato and spinach. Raw egg white contains a protein called avidin that binds biotin, which is one more reason to eat eggs cooked. Browse formulas in our hair, nail and skin collection.

Who should check with a doctor or pharmacist first

  • Anyone having blood tests. High-dose biotin can interfere with some laboratory tests that use biotin-based technology, including some thyroid hormone and heart tests, and give falsely high or low results. Always tell your doctor and the laboratory that you take biotin, and ask whether to pause it beforehand.
  • People with a thyroid condition or heart condition who are monitored by regular blood tests.
  • People taking anti-seizure medicines long term, which can lower biotin levels.
  • Pregnancy and breastfeeding: biotin is included in many pregnancy multivitamins; ask before adding a high-strength product.
  • Children: hair gummies are generally made for adults. Check the age on the pack and ask a doctor or pharmacist.
  • Anyone noticing sudden or patchy hair loss should see a doctor rather than relying on a supplement.

How to read a biotin label

  1. Find the biotin line and check whether it is in µg or mg.
  2. Read the %NRV: 150 µg is 300% NRV; 5,000 µg is 10,000% NRV.
  3. Check the serving size: hair gummies often list amounts per two gummies.
  4. Look at the other nutrients: hair formulas often add zinc, selenium, vitamin A and B6, which do have upper limits. Add them to your multivitamin.
  5. Count your biotin sources: taking a multivitamin, a B complex and a hair formula together can multiply your intake.

Bahrain and GCC notes

Hair and skin gummies are popular across the Gulf, and gelatine-based or pectin-based gummies can soften and stick together in the heat, so store them below 25°C and keep the lid closed. If you are having routine blood tests, for example a check-up before or after Ramadan, mention your biotin intake when booking. Explore the range in our hair, nail and skin collection.

Known Nutrition Hair, Skin and Nails, 60 Gummies
Label check

Reading a real label

Known Nutrition Hair, Skin and Nails, 60 Gummies
On the labelWhat it means
150 µg biotin per 2 gummies300% NRV, against the 50 µg reference intake
10 mg zinc, 55 µg seleniumBoth at 100% NRV; add them up if you also take a multivitamin
Serving = 2 gummiesEvery figure on the label is for two, not one
18 kcal per servingWorth knowing if you track calories
Figures from the product's own label. Always check the pack in your hand.See this product
EU-authorised health claims
  • Biotin contributes to the maintenance of normal hair
  • Biotin contributes to the maintenance of normal skin
  • Biotin contributes to normal energy-yielding metabolism
  • Biotin contributes to normal macronutrient metabolism
  • Biotin contributes to normal functioning of the nervous system
  • Biotin contributes to normal psychological function

Applies to products that provide at least 15% of the NRV per daily portion (a 'source of' the nutrient).

Frequently asked questions

Can biotin affect my blood test results?

Yes. High-dose biotin can interfere with some laboratory tests, including some thyroid and heart tests. Tell your doctor and the lab that you take it and ask whether to pause it first.

Is 10,000 µg of biotin safe?

EFSA has not set an upper limit, but UK guidance considers 900 µg or less a day from supplements unlikely to cause harm. Speak to a pharmacist before using very high-strength products.

Will biotin make my hair grow faster?

Biotin contributes to the maintenance of normal hair, but evidence that extra biotin changes hair in people who already get enough is limited.

What is the difference between µg and mg for biotin?

1 mg equals 1,000 µg. A product with 5 mg contains 5,000 µg, or 10,000% of the 50 µg NRV.

This page is general information from Healthana, not medical advice. Food supplements should not replace a varied, balanced diet and a healthy lifestyle. Speak to your doctor or pharmacist if you are pregnant or breastfeeding, take medication or have a medical condition. Editorial policy
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