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Biotin: What You Need to Know

Dr Karen Martin
Reviewed by Dr Karen MartinReviewed on 17 Jun 2025 | 4 minutes readNext review due: 16 Jun 2028
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Biotin, also called vitamin B7, is a water-soluble vitamin from the B complex group. It helps your body turn food—carbohydrates, fats, and proteins—into energy. Biotin is important for cell growth and is often linked to healthy hair, skin, and nails. You can find biotin in foods like eggs, nuts, seeds, beans, and whole grains. Most people get enough biotin from their diet, so biotin deficiency is rare. When someone does not get enough biotin, they might have thinning hair, weak nails, or skin rashes.

Biotin's benefits for hair health

Many people believe that biotin can make hair grow faster or thicker. Biotin helps your body make keratin, a protein that is a key part of hair. However, research shows that biotin supplements only help hair growth if you already have a biotin deficiency. If you are not lacking biotin, taking extra probably will not make your hair grow more.

Can Biotin Stop Hair Loss?

Biotin does not cure genetic hair loss, like male-pattern baldness. But if your hair is thinning because you do not have enough biotin, taking supplements can help your hair become stronger and thicker. Most studies that show biotin helps with hair regrowth focus on people who have a deficiency or certain health problems.

Who should take biotin?

Biotin supplements are most helpful for people who do not get enough biotin from food. This can happen during pregnancy, with certain stomach problems, or if you take some medicines for a long time. People with weak nails or thinning hair due to not enough nutrients may also benefit from biotin.

Biotin in Shampoos and Hair Products

Many shampoos and conditioners have biotin because it is believed to help hair. These products can make hair feel softer and look fuller by adding moisture, but the biotin in them does not get into your scalp or hair roots enough to make hair grow. The main benefit is that your hair may look and feel healthier, but it does not solve the real cause of hair loss.

Biotin Supplements

Biotin supplements are easy to find in stores. They are often advertised to help with hair, nails, and skin. Because biotin helps make keratin, some people think that taking more will help hair grow faster. But unless you have a deficiency, taking extra biotin does not usually make a big difference.

How much biotin do you need?

The recommended amount of biotin for adults in the US is 30 micrograms (mcg) per day. Most people can get this amount from a balanced diet. Some supplements have much higher doses, but there is little proof that more is better for most people. Always talk to a doctor before taking high-dose supplements.

Biotin in Food

You can get biotin from many foods, such as:

  • Eggs (especially the yolk)

  • Nuts like almonds and walnuts

  • Leafy greens like spinach and broccoli

  • Sweet potatoes

  • Whole grains like oats

  • Bananas

  • Beans and lentils

Cooking can lower the amount of biotin in food, especially in eggs. But eating a mix of cooked and raw biotin-rich foods should give you enough. Raw eggs have more biotin, but they also contain a protein called avidin that stops your body from using biotin, so cooked eggs are safer.

Is Biotin Safe?

Biotin is safe for most people, even at high doses, because your body gets rid of extra biotin in your urine. Taking too much can sometimes cause mild problems like skin rashes, acne, or stomach upset. High doses can also mess up some lab tests, especially for thyroid or hormone levels, so tell your doctor if you take biotin before any tests.

Signs of biotin deficiency

Although rare, biotin deficiency can happen, especially if you have stomach problems, take certain antibiotics for a long time, or eat a lot of raw egg whites. Signs include:

  • Thinning hair or hair loss

  • Weak, brittle nails

  • Dry skin or rashes

  • Feeling tired

If you notice these symptoms, see your doctor. They can check if you need more biotin or if something else is causing your symptoms.

Conclusion

Biotin is important for healthy hair, skin, and nails, but it is not a miracle cure for everyone. Most people get enough from food, and supplements are mainly helpful if you have a deficiency. High doses are usually safe but can affect lab tests. If you are worried about hair loss or think you might be low on biotin, talk to a healthcare provider before starting supplements. Eating a balanced diet with biotin-rich foods is the best way to stay healthy.

The AI in healthwords.ai refers to conversational search, while the only AI tools used for articles are grammar and language improvements -  medical content remains rigorously authored by healthcare professionals.

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This article has been written by UK-based doctors and pharmacists, so some advice may not apply to US users and some suggested treatments may not be available. For more information, please see our T&Cs.
Dr Karen Martin
Reviewed by Dr Karen Martin
Reviewed on 17 Jun 2025
Next review due: 16 Jun 2028
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