Biotin is an important vitamin that can promote healthy hair, skin and nails. Although it is often used in shampoos for hair loss, there is little evidence that biotin shampoos are effective in promoting hair growth. This is because shampooing doesn’t allow enough time for biotin to get absorbed through the skin. In fact, you are better off taking oral hair growth supplements that contain biotin than using a biotin shampoo.
Can Biotin Be Absorbed through Skin?
Yes, biotin can be absorbed through skin. In a human test, participants applied 7 grams of a topical ointment containing a concentration of 0.3 percent biotin per day, along with 1 to 4 grams of a steroid ointment. Results from this study found increased serum biotin levels in both healthy subjects and subjects with atopic dermatitis. The subjects kept the ointment on their skin until it was completely absorbed. The former group showed a 21 percent increase, while the group with atopic dermatitis showed an 81.7 percent increase in serum biotin. This shows that biotin can be absorbed through the skin.6
However, these tests involved leaving the biotin ointment on the skin. Biotin shampoo is naturally designed to be rinsed away, almost immediately after application which doesn’t give the biotin enough time to soak into the scalp and influence serum biotin levels to promote hair growth.
By comparison, studies have found that oral biotin is completely absorbed, even at doses up to 20 milligrams per day.7
Research Shows Oral Biotin can Promote Hair Growth
Biotin is often called “vitamin H” for its association with supporting healthy hair, but studies suggest it may also help to maintain healthy nails and skin. Initial research found that biotin exists in hair, skin, and nails to a significantly high degree.2 Research also shows that biotin plays a role in the infrastructure of keratin, a basic protein that makes up the connective fibers of skin, hair, and nails.3
Research on rats and humans has found that biotin deficiency may result in forms of alopecia. This hair loss has been shown to be offset by the supplementation of biotin. Biotin deficiencies are rare because of how ubiquitous the vitamin is in the average American diet, but there are numerous potential causes, including genetic predisposition to deficiency and certain pharmaceuticals.2 Avidin, a protein present in raw egg whites, is also known to bind tightly to biotin. This can prevent proper absorption of biotin, resulting in significantly low levels.4
A double-blind, placebo-controlled study evaluated the effect of oral biotin supplements on women with thinning hair. Patients were given either the biotin supplement or a placebo twice a day for a period of 180 days. By the end of the study, patients who took the biotin supplement showed a dramatic increase in terminal hairs, which are thick, long hairs in contrast with the thinner, fainter vellus hairs. These participants also had self-perceived improvements in scalp coverage, hair volume, and thickness of hair body after 90 days of treatment. After 180 days of treatment, participants noted additional improvements in hair shine, skin moisture retention, and general skin smoothness.5
Further research is necessary to determine the exact mechanisms of action involved, but it should be noted that most studies on biotin’s effects on hair growth and general hair health involve oral use as opposed to topical application.
If not biotin shampoo, what topical treatments actually help with hair growth?
1. Natural DHT Blockers
For the best results, we recommend using a shampoo that has a DHT blocker. Most forms of hair loss are caused by high levels of dihydrotestosterone, or DHT. High levels of this are been linked to androgenic alopecia, or female and male pattern baldness. High DHT levels in men are also linked to benign prostatic hyperplasia (BPH).11
Some common natural DHT blockers used in supplements and hair products include:
- Saw palmetto
- Stinging nettle
- Pumpkin seed oil
- Green tea
- Tea tree oil
- Lavender oil
Ketoconazole is a medication often used to treat infections caused by yeast and fungus. It is often incorporated into shampoos to treat seborrheic dermatitis, dandruff, psoriasis, and other fungal scalp infections.15 Additionally to these benefits, some research suggests that ketoconazole may have DHT blocking properties and may also reduce symptoms of hair loss. In a small pilot study, 15 participants with androgenic alopecia were given a topical regimen comprising ketoconazole shampoo, a hypoallergenic lotion, Rogaine foam, and Propecia. Studies showed that patients who used all four components of the regimen showed significant hair growth in just 30 days.16
3. Essential Oils for Hair Growth
Shampooing can strip your hair and scalp of their natural oils. Worse yet, dried out hair can cause irritation and inflammation that worsen hair loss. Make sure you use a conditioner after using shampoo. Choose one that contains argan oil and/or jojoba oil. Argan oil is rich in antioxidants, essential fatty acids, linoleic acid, and vitamins that can help to nourish your hair, increase hair elasticity, prevent breakage, and moisturize the scalp. The high antioxidant content can help to reduce inflammation that can result in itchiness, dandruff, and thinning hair.13
Similar to argan oil, jojoba oil provides rich moisturizing potential, which can prevent dryness in the scalp. Jojoba oil is also most similar chemically to natural oils produced by skin and scalp. The oil can nourish hair follicles, which may promote hair thickness and growth. Jojoba oil is also rich in antioxidants as well as several vitamins and minerals, including zinc, copper, vitamin C, and vitamin E.14
Minoxidil is one of the few FDA-approved hair loss treatments available over the counter. Minoxidil works as a vasodilator, meaning it widens blood vessels, allowing for more blood to travel into the scalp. The exact mechanisms of action are not well known, though some research suggests that minoxidil may help to enlarge hair follicles and expand your hair’s growth phase. This could potentially result in more hair covering the scalp.17
While it is still a good idea to use biotin-enriched shampoos, biotin supplements offer a more optimal method of providing your scalp with this hair healthy vitamin. Consult your doctor to determine if biotin supplements might be right for you.