How to Use Essential Oils for Hair Growth

Hair Health Hotline is your direct access to dermatologists, trichologists, hairstylists, and other beauty pros. Each story in this series tackles a common hair or scalp concern and offers science-backed solutions to care for your strands.

A quick internet search can give you the impression that essential oils can do it all. Sure, you can use them to diffuse a spa-esque aroma throughout your home, but they're also commonly used in homemade cleaning products, household deodorizers, and more. Unsurprisingly, essential oils have also found their way into hair care — you might've seen an essential oil featured on an ingredient list or in a TikTok post about DIY hair-growth solutions.

Even if you're fully on board with using essential oils in other contexts, you might still have questions about how to use essential oils for hair growth, and whether they're effective to begin with. Here to answer your questions, Esther Olu, cosmetic chemist and licensed esthetician, shares those details below.

Q: I'd like to try using essential oils for hair growth since my hair isn't as thick and full as it used to be. Which essential oils stimulate hair growth and how should I apply them?

A: Studies have linked multiple essential oils, such as rosemary and peppermint oils, to hair growth benefits, according to Olu. However, research on essential oils and hair growth is limited, and the oils aren't necessarily a miracle solution for hair loss, she adds.

Is Using Essential Oils for Hair Growth Effective?

"Factors that can affect hair growth or loss are genetic predisposition, diet, stress, and more," explains Olu. Since hair thinning or loss can result from multiple causes, it's often difficult to treat, so it's important to manage your expectations before trying essential oils for hair growth, says Olu. And the evidence that essential oils can improve hair growth is "very limited," so you shouldn't view them as a miracle treatment or overnight cure, says Olu.

With that being said, the studies that do exist have linked certain essential oils with possible hair growth benefits, including increasing strand thickness, increasing the number of hairs, or both, notes Olu.

Rosemary Oil

Rosemary oil helps increase hair density, i.e., the number of hairs growing from the scalp, says Olu. Some studies show the oil may do so by increasing blood circulation (which is key for the delivery of oxygen and nutrients to hair follicles), cellular turnover, and nerve growth, she says. During one study published in the journal SkinMED, 100 participants with androgenetic alopecia (a genetic hair loss condition) were split into two groups, and either applied rosemary oil or minoxidil (a medication that can treat hair loss) to their scalps for six months. Both groups experienced a significant increase in hair count.

Peppermint Oil

"Even though research is limited, peppermint oil may be helpful as it can help increase blood flow and circulation which may potentially encourage more hair growth," says Olu. During a study published in Toxicological Research, mice were split into four groups, and was topically treated with either saline, jojoba oil, minoxidil, or peppermint oil diluted in jojoba oil over four weeks. The peppermint oil group showed the most prominent effects on hair count after the four weeks. Keep in mind, the results of animal studies don't always apply to humans.

Lavender Oil

"Lavender oil possesses antimicrobial and anti-inflammatory properties and can help increase blood circulation in the scalp," notes Olu. In a study published in Toxicological Research, mice were split into five groups and received topical treatments with saline, jojoba oil, minoxidil, 3 percent lavender oil, or 5 percent lavender oil over the course of four weeks. Both lavender oil groups and the minoxidil group had a significant increase in number of hairs.

Tea Tree Oil

"Tea tree oil is not necessarily directly linked to hair growth, but it possesses antimicrobial, anti-inflammatory, and antibacterial properties to help scalp health," notes Olu. And scalp health can factor into hair growth. The results of one study published in the Journal of the American Academy of Dermatology suggest that a 5 percent tea tree oil shampoo can decrease scalp itchiness and greasiness, possibly due to the essential oil's antimicrobial properties.

Thyme Oil

Like some of the above oils, thyme oil helps improve circulation in the scalp and may help prevent hair loss or thinning, says Olu. Throughout a study published in the Gulhane Medical Journal, 40 people with alopecia areata were split into two groups. Over 12 weeks, the first group was treated with a mixture of thyme, rosemary, lavender, evening primrose, and cedarwood oils with jojoba and grapeseed oils, and the second group was treated with a combo of just jojoba and grapeseed oils. The rate of hair growth throughout the study was significantly higher in the first group (which had been treated with thyme and other essential oils) compared to the second.

How to Use an Essential Oil for Hair Growth

If the above has you excited to try using essential oils for hair growth, there are a few things you'll want to keep in mind. While you may view essential oils as a "natural" beauty ingredient, that doesn't mean they're always harmless. "Due to the potency of essential oils, I highly caution consumers and recommend that they patch test essential oils — and any new product in general — prior to usage," says Olu. Doing a patch test will allow you to see how your skin will react and ward off any potential allergic reactions before using essential oils directly on your scalp. A patch test is best done by applying a drop of the oil to the skin, preferably the back of the wrist, and waiting at least an hour to see if any rashes or reactions occur.

And given essential oils' potency, it's safest to dilute them with a carrier oil (e.g. grapeseed or jojoba oils) before applying them to your scalp, according to Olu. "If not diluted, [essential oil application] can increase the risk of one's scalp and skin being exposed to irritation and other side effects," she says. As for exactly how to mix essential oils for hair growth and thickness, dilute two to three drops of your chosen essential oil in a carrier oil to create a mixture that you can then massage into your scalp, says Olu. You can use it as a weekly treatment, in which you leave it on for around 30 minutes before rinsing it out, as Shape previously reported.

The bottom line: Some essential oils may (keyword: may!) help increase hair density and/or thickness. If you decide to try an essential oil for hair growth, it's best to patch-test and dilute the oils to lower your risk of causing irritation in the process.

Have a hair health question you want answered? Send your Q to hairhotline@shape.com for a chance to have it featured in a future installment of Hair Health Hotline.