Mustard Oil for Hair: Benefits and How to Use It

Mustard: a condiment for hot dogs, yes, but a haircare ingredient? To be fair, we're talking about mustard oil, rather than the yellow stuff in the squirt bottle (so please keep reading before reaching for the French's). Conduct a quick Internet search and you'll see plenty of info touting it as a solution for everything from dandruff to hair loss, not to mention countless YouTube videos of women dousing their heads in it. So, how exactly can this little seed be so good for your hair? We tapped some experts to unpack the mysteries around mustard oil.

It turns out that mustard oil may, in fact, have some benefits for both the hair and scalp. Extracted by pressing mustard seeds, Ayurvedic medicine has used it to treat various issues, including hair and scalp problems. Keep reading to find out exactly how you can boost your hair care routine with this ingredient.

Benefits of Mustard Oil for Hair

"Mustard oil is rich in fatty acids, such as omega 3s and 6s, various minerals including calcium, iron, and zinc, as well as antioxidants such as vitamin B and E," says Chwalek. In short, the tiny but mighty mustard seed is filled with a variety of potentially good-for-you hair and skin nutrients. While it's a mainstay in Ayurveda, it's worth noting that it isn't FDA-approved for oral consumption in the U.S. because it can contain a high concentration of toxic erucic acid. But people can use the oil topically on the scalp and hair, adds Chwalek. To that point, mustard oil has the potential to do the following:

• Reduces inflammation on the scalp: According to Chwalek, mustard oil contains omega fatty acids and antioxidants, both of which can provide essential nutrients and act as anti-inflammatories.
• Has anti-bacterial and anti-fungal properties: This makes mustard oil a potentially good option to address issues such as dandruff and seborrhea, says Chwalek. In addition, the mustard seed also has anti-parasitic effects, which make it effective against a particular type of mite found on the scalp, notes Gaunitz, who has studied and worked with mustard oil extensively.
• May help promote hair growth: Chwalek notes that one study of a topical herbal oil (which used mustard oil as the base) found it to be effective against dandruff and good for reducing hair shedding. There are several ways it may do this: First, there are the previously mentioned anti-inflammatory properties, which may help prevent inflammation-induced hair loss. Secondly, Chwalek says that certain compounds in mustard may affect particular receptors in the hair follicle that play a role in controlling hair growth. And finally, for some people, hair loss can be caused by a parasite known as demodex folliculorum, one of two types of demodex mites that live on human skin, explains Gaunitz. He adds that these mites affect the hair follicle and impair hair growth, and he says that the mustard seed can kill these mites. The big caveat? Gaunitz says Demodex folliculorum feed on oil; as such, he advises against using mustard oil on the scalp and instead says that tinctures made with ground mustard powder are a much better option (more on that to come).
• Improves overall appearance of the hair: While all of these benefits are primarily centered around mustard oil's effects on the scalp, because it is so rich in fatty acids, it can also help smooth split ends and make your hair shinier, says Chwalek.

Hair Type Considerations

Mustard oil can be used for all hair types, but perhaps not all skin types. All the experts we spoke with agree that it can be extremely irritating—we're talking redness, stinging, and even burning, thanks to skin-irritating compounds such as (again) erucic acid and allyl thiocyanate, explains Chwalek. A patch test to ensure your skin doesn't react negatively is a must before you slather it all over your scalp; those with sensitive skin should proceed with extreme caution.

Similarly, it's often recommended to combine mustard oils with other nourishing oils like baobab to try to minimize the likelihood of irritation. "Baobab is a skin-nourishing carrier oil that helps soften dry skin and penetrates very well into the skin," Emmanuel says. "It is used [to treat] other scalp disorders such as psoriasis and has a great amount of essential fatty acids."

How to Use Mustard Oil for Hair

While there is some science to back up the benefits of mustard oil, there are no studies verifying the best way to use it, Chwalek points out. "Generally speaking, you could do treatments weekly or monthly," says Chawlek. Though again she notes that this is based on anecdotal, rather than scientific, evidence. Regardless of your chosen application, make sure you do that patch test first and follow up with a thorough shampoo.

• Try a "quick oiling": "Take about a teaspoon of mustard oil and massage it into your scalp for about five minutes immediately before shampooing," suggests Friese.
• Pop a shower cap on: Alternately, to up the ante, you can apply the same amount onto the scalp, then pop on a shower cap and let it sit for about 30 minutes, she says. The shower cap will trap heat and may help the oil penetrate better. If you're going to do the latter, it's a good idea to combine the mustard oil with another oil; coconut is one good option, particularly if your hair is extremely dry, says Friese. This may help minimize the likelihood of the mustard oil irritating your scalp and give you additional benefits from the secondary oil.
• Create a tincture: Gaunitz says that the best way to reap the topical benefits of mustard is to create a tincture with ground mustard seed powder, rather than using it in oil form. (He also adds that it's very challenging to find pure, high-quality mustard oil and that many of the products on the market cut it with all kinds of vegetable oils that can ultimately counteract the benefits of the mustard.) He suggests combining 1/4 teaspoon with two ounces of water for a topical application, though underscores that this needs to be done with caution given the likelihood of irritation.