Medically reviewed by Mary Lucas, RN
Written by Our Editorial Team
Last updated 6/21/2022
If you’ve ever searched for information about treating hair loss, improving your hair growth and maintaining healthy hair, you may have heard of biotin.
Biotin, or vitamin B7, is a water-soluble B vitamin that’s a popular ingredient in hair growth and hair care products.
Although biotin isn’t a proven, FDA-approved treatment for preventing male pattern baldness like medications such as finasteride or minoxidil, there’s some scientific evidence that it offers hair growth benefits, particularly in people who are biotin deficient.
We’ve discussed much of this in our guide to biotin for hair growth, which looks at the current scientific research on the benefits of biotin supplements and biotin-rich foods.
Since biotin is a supplement rather than an FDA-approved medication, there are no guidelines on how much to take each day, although there are recommendations from sources such as the Food and Nutrition Board at the National Academies of Sciences, Engineering, and Medicine.
This lack of concrete information can make it confusing and difficult to work out how to incorporate biotin into your hair care and hair loss prevention routine.
Below, we’ve explained what biotin is, as well as how it plays an important role in the growth of your hair, nails and other parts of your body.
We’ve also discussed how much biotin you should take daily for ideal hair health, as well as the potential risks, side effects and other issues that could develop if you take an excessive amount of biotin.
Biotin, or vitamin B7, is an essential vitamin that’s found in numerous foods, including milk, eggs and bananas. It plays a major role in several important processes within your body, including the production of enzymes that allow you to break down carbohydrates and fats.
Your body also relies on biotin for processes such as cell signaling, histone modification and the regulation of your genes.
Like many other vitamins, biotin is available as a dietary supplement in products like our Biotin Gummy Vitamins.
Most people take in sufficient amounts of biotin through their diet. However, a small percentage of people -- in particular, pregnant or breastfeeding women, people who use alcohol frequently, and individuals with biotinidase deficiency -- are at risk of developing biotin deficiency.
Some medications, such as anticonvulsants, can also affect biotin production and contribute to biotin deficiency.
If you’re deficient in biotin, you may notice that you’re more likely to develop visible skin issues, such as scaly or red skin. Biotin deficiency can also contribute to thinning hair, brittle nails and an increased risk of neurological problems, such as depression or hallucinations.
Currently, there’s no FDA recommended dietary allowance (RDA) for biotin, meaning there’s no widely accepted recommended daily dose.
The National Institutes of Health recommends a biotin intake of 20 to 30 micrograms (mcg) per day for teenagers and adults to prevent biotin deficiency.
However, this is a total biotin intake that includes all sources of biotin, such as common foods and cooking ingredients.
Biotin is absorbed from most foods by the microflora of the large intestine. Most people produce a sufficient amount of biotin via their digestive system to avoid any need for biotin supplements, meaning there’s no essential minimum dose of biotin — only recommended doses.
Because of this, biotin supplementation is usually only necessary if you’ve been diagnosed with a biotin deficiency, or if your diet doesn’t provide an adequate intake of biotin.
However, it’s common and normal to take a small daily dose of biotin to prevent biotin deficiency and potentially promote hair health.
Biotin is generally a safe and effective supplement, with few side effects of biotin reported even with very high intakes.
Can you overdose on biotin? According to the Office of Dietary Supplements, which is a part of the National Institutes of Health, there’s no evidence that biotin is toxic to humans. Studies have found that biotin doesn’t produce adverse effects even at doses of 10 to 50mg per day.
With this said, it’s generally best not to take too much biotin. Taking too much biotin may reduce the accuracy of certain blood tests -- a topic we’ve discussed more below. It’s also wasteful, as there’s no evidence that very high doses of biotin offer any additional health benefits.
Unless you’ve been prescribed biotin at a certain dose by your healthcare provider (for example, to treat a biotin deficiency), it’s best to stick to the recommended daily dose listed on your biotin supplement.
Biotin is found in many common foods, making it an easy vitamin to consume via your diet. You can find biotin in milk, egg yolks, and many meat and seafood products.
Good sources of biotin include:
There are also small amounts of biotin in plain yogurt, oatmeal, whole wheat bread, bananas, apples and other types of fresh fruit.
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Biotin deficiency isn’t common. In fact, there are no reported cases of biotin deficiency occurring in people with normal, healthy eating habits.
Symptoms of biotin deficiency include:
Hair loss on the body
Scaly, red skin near body openings
Paresthesias (burning or prickling sensations)
In children and infants, biotin deficiency may cause lethargy, developmental delays and a lack of muscle tone (referred to as hypotonia).
If you’ve noticed any of the symptoms above and think a biotin deficiency may be the cause, it’s important to let your healthcare provider know.
There’s some scientific evidence to suggest that using biotin supplements, even at a moderate dosage, could interfere with certain laboratory tests used to diagnose thyroid disease and other conditions.
Specifically, daily use of supplements that contain biotin has been linked to inaccurate readings for lab tests used to measure levels of thyroid hormone. This has resulted in some biotin users receiving test results that falsely indicate hyperthyroidism or Graves' disease.
Use of biotin supplements has also been linked to low results on troponin tests, which are often used to diagnose stroke, heart attack and other cardiovascular conditions.
False lab test results can result in misdiagnosis, meaning you may be diagnosed with a medical condition you don’t have and prescribed medication that could negatively affect your health.
To avoid misdiagnosis, it’s important to inform your healthcare provider about any supplements you use, including supplements that contain biotin, before undergoing any type of blood test.
As a supplement, there’s no recommended dietary allowance (RDA) for biotin. However, most sources -- including the National Institutes of Health -- recommend a total biotin intake of 20 to 30 micrograms (mcg) per day for teenagers and adults.
If you eat a healthy, balanced diet, you likely consume enough biotin already. However, if you feel worried about potentially becoming deficient in biotin, you can increase your intake with a daily biotin supplement such as our Biotin Gummy Vitamins.
Biotin supplements are safe and may be effective at treating certain forms of hair loss. However, like with other supplements, it’s important to use them responsibly to make sure you don’t affect your health and wellbeing.
If you’re worried about overusing biotin, or have any questions about using biotin safely, it’s best to talk to your healthcare provider for personalized advice and assistance.