Does Biotin Work for Brittle Nails?

Affiliate Disclosure: I receive a small commission for purchases made via affiliate links.
How to cite: Wong M. Does Biotin Work for Brittle Nails?. Lab Muffin Beauty Science. July 19, 2016. Accessed April 22, 2024.

Biotin, also known as vitamin B7 or vitamin H, pops up in every supplement marketed for strengthening hair and nails. Do biotin supplements actually work for brittle nails?

Does Biotin Work for Brittle Nails?

The answer is – it depends. Gah! Read on for the gory details…

Are you getting enough biotin in your diet?

Nutritional supplements generally only make a difference if you’re not getting enough of that nutrient normally, and biotin seems to play by this rule.

The daily recommended intake of biotin for adults is 30 μg/day, and a Western diet generally contains enough biotin. You can find biotin in leafy green vegetables, nuts (peanuts and almonds in particular), avocados, corn, cooked eggs, liver, salmon and meat. Some intestinal bacteria make biotin, which could also contribute to your overall consumption.

Does Biotin Work for Brittle Nails?

Some factors can decrease your biotin though. Biotin seems to be lower with high alcohol consumption, smoking, gastric acid disorders, in burn patients, epileptics, athletes, the elderly and with some inborn genetic disorders. Pregancy and breastfeeding also decrease biotin.

Eating uncooked egg whites can also decrease biotin, even though cooked eggs are a good source! Raw egg white contains a protein called avidin which binds tightly to biotin, preventing it from working. Cooking the egg destroys the avidin.

How can I tell if I have a biotin deficiency?

As well as thin nails that are brittle and break easily, other signs of biotin deficiency are:

  • hair loss
  • conjunctivitis (eye infections)
  • a red scaly rash around on face and genitals
  • neurological problems such as depression, lethargy, numbness and tingling

What’s the evidence that biotin works?

There have been a few clinical studies on the effect of biotin supplements on brittle nails. In these studies. 2.5 mg were taken each day for several months, and about two-thirds of women had improved nails (thicker, harder, less splitting).

Does Biotin Work for Brittle Nails?

It’s worth noting that about 1/3 of women in these trials saw no effect. This is why it’s thought that you need to have a biotin deficiency to see any improvement with biotin supplements. If your brittle nails aren’t due to a biotin deficiency – for example, if your nails are brittle from using acrylics – then it’s unlikely to have much of an effect.

Are there any side effects of biotin?

Luckily, there’s almost no risk of overdose with biotin, unlike with many common supplements, so it’s quite safe in that regard. However, some people who take biotin supplements have found that they’re more prone to acne breakouts. It’s been suggested that this is due to the extra biotin blocking the absorption of pantothenic acid (vitamin B5), which could cause acne.


The best way to get biotin into your system is through food, but if you have brittle nails and you think you might have a biotin deficiency, taking a biotin supplement (2.5 mg/day) could help. Record the condition of your nails regularly while you take the supplement to check if it’s having any effect, and if you get acne breakouts, you may want to stop taking it.


LG Hochman, RK Scher & MS Meyerson, Brittle nails: response to daily biotin supplementation, Cutis 1993,51, 303-305.

GL Floersheim, [Treatment of brittle fingernails with biotin], Z Hautkr 1989, 64, 41-48.

VE Colombo, F Gerber, M Bronhofer & GL Floersheim, Treatment of brittle fingernails and onychoschizia with biotin: scanning electron microscopy, J Am Acad Dermatol 1990, 23, 1127-1132.

This post contains affiliate links – if you decide to click through and support Lab Muffin financially, thank you! For more information, see Disclosure Policy.

Skincare Guide

Related Posts

8 thoughts on “Does Biotin Work for Brittle Nails?”

  1. Loved this post, I’ve always found the raw vs cooked protein binding egg trick fascinating 🙂 Love chemistry.

    I can share my own experience, because I’ve experimented on myself with biotin. I took twice the dose, meaning 5 mg. Hair: didn’t start growing QUICKER, but it’s like many hair follicles woke up – so. many. baby. hairs. New growth 🙂 Nails: didn’t take biotin for the nails, but I’m a nail blogger so I noticed some changes, I paint my nails all the damn time. DEFINITELY stronger nails, and that’s with acetone abuse. Thicker, and harder. Acne breakouts: oh yes. That’ a real side effect. Through MORE experimenting I actually found a solution to this, what you need to combine biotin with to avoid side effects.

    Such an enjoyable post, like always 🙂

    • Hi, Catherine;

      given that I have both crap nails (and hair) and am prone to acne breakouts, what solution did you find? I tried searching your blog to see if you’d posted about it but ‘biotin’ came up with no hits.

    • Ooh have you written a post with the solution? Please let me know if/when you have! You’ve got me intrigued 🙂

  2. I always use a straight biotin supplement as the hair/skin/nails ones often break me out. I am actually not deficient at all in it (I get checked regularly and without the supplements, my levels are really good) but the added supplement helps. My hair and nails have always grown quickly but the biotin helps the strength 🙂

    • It could be that the recommended values in use are lower than what we actually need for optimal health – nutrient guidelines are often revised e.g. vitamin D is getting a lot of attention recently! 🙂

  3. I literally get so excited when there’s a new blog post in my mail box from you. The science, the pictures, the evidence, the conclusions- all of it is so well written! Love Biotin and I probably overdose on it, but it makes my hair grow! hahah Thanks for another great one!

  4. A few years back, my fingernails would constantly break every time I accidentally lightly tapped it on something. I was frustrated because my toenails were mega tough, haha. I started taking a Collagen-Biotin supplement, and BOOM. My fingernails became stronger and I could finally grow them out without fear of cracking them. I’ve stopped taking them since then, but my nails are still good. I feel like I did have a deficiency (with a lot of other vitamins), and taking the supplements was a little (or big) push towards figuring out what vitamins and nutrients my body was lacking.

  5. Thank you for this post! I have been trying to grow out my nails since I was 10, and they would always break. I have tried everything, from strengthening top coat, to nail treatments, and nothing worked. I tried Biotin and it didn’t make my nails break any less, but it did make them grow faster. It also made my hair grow like crazy.


Leave a Comment