Biotin has become a staple in the hair care industry, appearing in everything from shampoos and serums to supplements and gummy vitamins. Its widespread use has led many people to believe it is the key to achieving longer, thicker, healthier hair. But according to dermatologists, biotin may not live up to its reputation for most people.
To separate fact from fiction, experts weighed in on what biotin really does, who might benefit from it, and which hair growth solutions are more likely to deliver visible results.
What Is Biotin?
Biotin is a B-complex vitamin that plays a role in converting carbohydrates into glucose, which the body uses for energy, explains Dr. Elizabeth Bahar Houshmand, a double board-certified dermatologist in Dallas. It is also considered essential for skin, hair, and nail health, according to Dr. Kathleen Suozzi, an associate professor of dermatology at Yale University.
Because biotin helps support hair and nail strength, it is a common ingredient in hair care products. It typically appears either as an oral supplement or as part of topical formulas such as shampoos and conditioners.
Do Biotin Supplements Promote Hair Growth?
For most healthy individuals, biotin supplements are unlikely to make a noticeable difference in hair growth, says Dr. Joyce Davis, a dermatologist based in New York City. If someone is already getting enough biotin from their diet, additional supplementation will not be absorbed in a way that boosts hair growth. Excess B vitamins are simply excreted in the urine.
Adults need about 30 micrograms of biotin per day, a requirement that most people meet through a balanced diet. Foods rich in biotin include meats, eggs, fish, seeds, nuts, and vegetables such as sweet potatoes.
Biotin deficiencies can lead to hair thinning or hair loss, and supplementation may help in those rare cases, according to Dr. Houshmand. However, true deficiencies are uncommon. She also cautions that high doses of oral biotin can interfere with certain lab tests, including those that assess thyroid and heart function.
Does Biotin Shampoo Help Hair Grow?
Topical biotin products, including shampoos, are also unlikely to stimulate hair growth, experts say. While some people may notice that their hair appears thicker or fuller after using a biotin shampoo, that effect is usually cosmetic rather than biological.
“Different conditioning agents can coat the hair and make it seem thicker,” Dr. Davis explains. “But in terms of topical biotin penetrating the scalp and affecting the hair follicle, that’s wishful thinking.”
That said, Dr. Houshmand notes one potential benefit: topical biotin may help hydrate the scalp. This can be useful for people who struggle with dryness or flaking, even if it does not directly promote hair growth.
Better Options for Hair Growth
For those serious about addressing hair thinning or loss, dermatologists suggest looking beyond biotin. One ingredient that has gained attention in recent years is rosemary oil, which some studies and experts believe may help support hair growth.
An example is Mielle Organics Rosemary Mint Scalp & Hair Strengthening Oil, a popular and affordable product among consumers. Hairstylist Rogerio Cavalcante previously noted that this formula contains a relatively concentrated form of rosemary oil compared to similar products and is easy to incorporate into a wash-day routine. The brand recommends applying it to the scalp or using it on the ends as a split-end treatment.
The Bottom Line
Biotin remains an important nutrient for overall health, but for most people, it is not a miracle solution for hair growth. Supplements are unlikely to help unless a deficiency is present, and shampoos containing biotin may improve the look and feel of hair without affecting growth at the follicle level.
For meaningful results, experts advise focusing on evidence-backed treatments and consulting a dermatologist to identify the underlying cause of hair loss and the most effective treatment options.
