Perhaps you’re trying to grow your hair, get your skin glowing, or stop your nails from snapping all the time. A quick Google search or a scroll through TikTok, and you might be presented with biotin supplements as the magical solution. But what actually is biotin – and, most importantly, is it the miracle vitamin that people claim it to be?

What is biotin?

Biotin is also known as vitamin B7. It’s an essential nutrient that plays a number of important roles in the body, from helping enzymes metabolize carbohydrates, fats, and amino acids to being involved in regulating genes and cell signaling.

Biotin supplements – fact vs. fiction

Biotin is found in a bunch of different foods in varying amounts, ranging from animal products like eggs, liver, and fish; but also some nuts, seeds, fruit, and vegetables. Like many other vitamins, however, it’s also found in supplements, and easy-to-take forms of it like gummies are now a staple on drug and beauty store shelves.

On their labels, you’ll often find mention of three things that are supposedly supported by taking biotin supplements: hair, skin, and nails. 

While it is true that if someone isn’t getting enough biotin (the formal term for this is biotin deficiency) some of the key symptoms are hair loss, scaly, red skin rashes, and brittle nails, biotin deficiency is rare – particularly if someone is eating a balanced diet. 

Groups at risk of not getting enough biotin include those with a rare genetic disorder called biotinidase deficiency, those with chronic alcohol exposure, and people who are pregnant and breastfeeding (even if they’re eating enough food with biotin in). Some people might also have lower biotin levels due to taking long-term antibiotics or anticonvulsant medications.

As such, for healthy people without a biotin deficiency, there’s no strong evidence that taking a biotin supplement will do anything to improve their hair, skin, or nails. It’s recommended to speak with a doctor before taking supplements, especially if you are pregnant, breastfeeding, or taking other medication.

That’s not to say there haven’t been any studies investigating whether biotin supplements can help people with hair, skin, or nail issues – but there aren’t all that many, and those that do exist tend to have problems like small sample sizes, biases, or a lack of a placebo group. 

“[Randomized controlled trials] studying biotin supplementation in hair and nail disorders are severely lacking,” reads a 2021 review in the Journal of the American Academy of Dermatology. The authors added, “The benefits of biotin supplementation remain unsubstantiated.”

In another recent review of studies exploring the use of oral biotin for hair growth or quality, the authors found only three studies that met their inclusion criteria (which included a study being in humans, available in English, and not a case report or case series). Of those, none had strong evidence to suggest biotin helped with hair growth or quality, particularly as two of them had multiple potential biases.

In any case, there are many different factors beyond biotin that can contribute to problems with hair, skin, and nails. To find a solution that works, the most reliable thing to do is consult a healthcare professional – they can run tests to help find the root cause of an issue, and depending on what that is, the best way to tackle it.

Is taking biotin supplements dangerous?

While it’s better not to assume that a lack of biotin is causing problems, taking a supplement containing it is generally safe for most people – it’s unlikely to overdose on it as it’s water soluble, meaning that you’ll simply pee the excess out.

However, biotin can interfere with certain medical tests – and that presents a risk, to the point that the US Food and Drug Administration (FDA) has issued warnings about it.

“The presence of high levels of biotin in patients’ blood can cause clinically significant incorrect results in certain lab tests, leading to falsely high or falsely low results, depending on the type of test,” the FDA said in a 2019 brief.

“The FDA is particularly concerned about biotin interference causing a falsely low result for troponin, a clinically important biomarker to aid in the diagnosis of heart attacks, which may lead to a missed diagnosis and potentially serious health implications.”

So, if you’re due any diagnostic tests any time soon, it’s probably best to go easy on the hair gummies.

All “explainer” articles are confirmed by fact checkers to be correct at time of publishing. Text, images, and links may be edited, removed, or added to at a later date to keep information current.

The content of this article is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of qualified health providers with questions you may have regarding medical conditions.