Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 3/11/2021
Worried your hair is starting to thin?
According to the Canadian Dermatology Association, about 40% of women will deal with some degree of hair thinning by age 50, with some noticing their hair starting to thin and fall out more frequently before turning 30.
In short, thinning hair is far more common than you might think.
It’s also a complex problem with a range of potential causes, from nutritional deficiencies to hormonal issues, genetics and stress all potentially contributing to a thinner-than-normal head of hair.
Luckily, it’s also something that you can treat, often surprisingly easily.
From medications such as minoxidil to shampoos, a variety of products can help you thicken up your hair and fight back against female hair loss.
One of these substances is biotin, a B vitamin that helps your body metabolize carbohydrates, protein and fat.
It’s also an essential vitamin for production of keratin—an essential structural protein that makes up your hair.
Sound familiar? You might have seen biotin mentioned before on the labels of shampoo bottles, or on over-the-counter hair and skin supplements.
Below, we’ve explained what biotin is, as well as how regular use of a biotin-rich shampoo can help you treat and prevent thinning hair.
Biotin is naturally produced by the body as a byproduct of digestion. Normally, a healthy body produces just enough biotin to maintain healthy hair, skin, and nails without any major need for supplementation.
Assuming you have a healthy diet, you probably also consume biotin through your food.
Biotin is found in eggs, salmon, pork, sunflower seeds, and sweet potatoes to name a few.
Although some amount of biotin is lost when you cook biotin-rich foods (meaning you’ll want to stick with raw, biotin-rich vegetables if you’re concerned about your biotin intake), there’s still a reasonable amount of biotin in cooked food.
Since biotin is an important building block for keratin, it’s a key part of making sure your hair is strong, thick and healthy.
Generally, biotin deficiency is rare. Most people produce more than enough biotin through food for hair growth to occur.
Only a small number of people suffering from measurable, confirmed biotin deficiencies. In general, the chance that you’re lacking in biotin is fairly slim.
However, women suffering from hair loss tend to have biotin deficiencies in higher numbers than the rest of the population.
According to a 2016 study of 541 women experiencing hair loss,, 38% of participants experienced measurable deficiencies of biotin.
In short, while biotin deficiency is rare if you’re a woman with noticeable hair thinning, there is a risk that lower-than-normal levels of biotin could be the cause.
Beyond hair thinning, some of the most common symptoms of a biotin deficiency include loss of depression and the development of a dry, scaly rash around your nose, eyes or genitals, as well as unusual fat distribution on the face and a swollen or painful tongue.
Worried you might have low levels of biotin?
Bio deficiencies are easy to detect using a simple blood test, meaning the best approach is to schedule an appointment with your healthcare provider to see if you’re deficient or not.
Biotin is available as a health supplement. It’s also frequently used in hair loss treatment shampoos.
Our Hers hair loss shampoo contains biotin as one of several active ingredients designed to prevent hair thinning and encourage healthy hair growth.
So, does it work? Unlike many other shampoo ingredients that make big promises, biotin for hair loss really is backed up by proven science.
First, it’s closely linked to an improvement in hair growth in one recent study.
Sixty women took part in the study, with 30 receiving a placebo and the other 30 receiving a biotin supplement. At the end of the 90 day study, women in the biotin group noticed an improvement in hair growth.
It’s important to point out that this study was funded by Lifes2good, Inc., which manufactures a biotin-based supplement.
The supplement given to the biotin group also contained a variety of other hair growth ingredients.
Other studies also back up the idea that biotin for hair loss can contribute to a reversal of hair loss and an improvement in growth.
In a 2014 study, children with a medication-induced biotin deficiency showed a reversal in hair loss symptoms after consuming a biotin supplement.
Far as safety goes, biotin has a solid record. Several studies have shown no adverse effects from biotin supplementation as high as 200mg daily, taken orally.
When administered intravenously at 20mg daily in patients with preexisting biotinidase deficiency, no symptoms of toxicity were reported, either.
Used topically as a shampoo ingredient, biotin appears to be safe and suitable for regular application.
However, it’s worth noting that because the FDA hasn’t instituted reference daily intake (RDI) numbers for biotin, and because they haven’t extensively tested biotin supplementation’s impact on pregnant women or infants, none of this information should be considered gospel.
We believe biotin shampoo — and biotin supplements — is generally safe and well-tolerated with few notable side effects, but more research is needed before we can say anything conclusive.
Overall, scientific research on biotin shows that while it isn’t a miracle ingredient for reversing hair loss, it does have measurable, positive effects for your hair health.
In short, while it works, the unique problem it solves — biotin deficiency — might not be what's causing your hair loss.
While it’s unlikely that your hair loss is caused by deficient levels of biotin, there are still several reasons to use a biotin shampoo.
if you’re part of the minority of women whose hair loss is caused by a biotin deficiency, using a shampoo that contains biotin may help you increase your body’s biotin levels without having to rely on an oral supplement.
Second, most biotin shampoos (such as our Hers Shampoo) contain other ingredients designed to reverse thinning and encourage healthy hair growth, such as saw palmetto and pumpkin seed oil.
Finally, there are no risks to using a biotin shampoo.
Unlike some medications, which can often come with unwanted side effects, biotin isn’t linked to any harmful health effects, meaning that even if it doesn’t improve your hair health and thickness, it isn’t going to harm you.
On the whole, biotin may be helpful for promoting hair growth and preventing thinning if you’re deficient.
If you’re not, using a biotin shampoo isn’t going to hurt, although it might not produce the hair growth results you’re hoping for.
Want more tips on keeping your locks luscious as possible? Don't keep asking "why is my hair so dry" or "how to stop hair shedding" head on over to the hers blog and get your hair facts.