Hair oils could have a variety of benefits. They can moisturize your scalp and hair follicles, promote hair growth and reduce the chances of hair falling out. But that isn’t all—some hair oils, like rosemary oil, even have therapeutic benefits, helping alleviate irritated scalp skin and reducing flaky dandruff. Basically, they’ll make your hair look healthier and stronger overall.
Meet the experts: Dr. Brendan Camp is a board-certified dermatologist at MDCS Dermatology, Dr. Ramya Garlapati is a board-certified dermatologist, co-founder of Skin Medicinals and skincare expert, Dr. Lauren Penzi is a board-certified dermatologist specializing in medical and cosmetic dermatology.
Wondering how hair oils can accomplish so much? Well for starters, they help kick sebum, your skin’s natural oil, into gear.
“Sebum is secreted by sebaceous glands attached to hair follicles,” says Dr. Brendan Camp, board-certified dermatologist at MDCS Dermatology. “By coating the hair shaft with oil, sebum helps soften and smooth hair and strengthens it to prevent breakage.”
If you’re new to using hair oils, rosemary oil is a pretty good place to start. As you may have seen on your TikTok FYP, it has many benefits for treating the scalp and hair and this is one social media craze that actually has research to support its claims, says Dr Ramya Garlapati.
Ahead, learn everything you need to know about using rosemary oil for hair growth, including how to use it and its potential side effects.
What Is Rosemary Oil?
This oil is from the Rosemarinus officinalis—or rosemary—plant, a fragrant evergreen shrub native to the Mediterranean region that sprouts blue or whitish flowers. You’re probably most familiar with this plant as a garnish for some of your favourite savoury dishes—it has an earthy taste and many powerful compounds that provide myriad health benefits.
How Can Rosemary Oil Benefit Hair?
“Rosemary has been shown to have significant antimicrobial, anti-inflammatory, anti-oxidant, anti-apoptotic, anti-tumorigenic, antinociceptive and neuroprotective properties,” says board-certified dermatologist Dr Lauren Penzi. So, it can promote hair growth and prevent breakage by coating the hair with fortifying oils.
A 1998 randomized, controlled, double-blind study of 86 patients with alopecia areata found that an aromatherapy essential oil blend of thyme, rosemary, lavender and cedarwood was way more effective than the placebo. Basically, rosemary oil is equally as effective as topical minoxidil, which treats androgenic alopecia, but it’s safe for all hair loss patients.
Rosemary oil helps hair grow by “blocking the effects of DHT, which is a type of testosterone that is normally responsible for shrinking hair follicles that can lead to hair loss,” says Dr Garlapati. “It increases blood flow to hair follicles, which increases the delivery of oxygen and nutrients promoting hair growth.”
It can also reduce scalp irritation from issues like dandruff. That’s because “it is thought to be a vasodilator, meaning it increases blood flow in scalp skin,” says Dr Camp. “This improved circulation is thought to help maintain hair in the growing phase and prevent shedding.”
Who Can Use Rosemary Oil?
Anyone can use rosemary oil to treat their scalp, but it’s especially helpful for those experiencing dandruff, hair shedding, thinning, breakage, or loss—in specific, “those who may want to take a more natural approach to hair loss management or would like to add rosemary oil as a supplemental treatment to their regimen,” says Dr. Garlapati.
Just remember to discuss the cause of your hair loss with a dermatologist before trying an at-home treatment like rosemary oil. “Others with more sensitive skin may want to use rosemary oil with caution to avoid skin irritation,” Dr Camp says.
What Are The Side Effects Of Using Rosemary Oil On Hair?
It’s safe for all hair types, even colour-treated hair, says Dr Garlapati. “There is little to no risk of any side effects,” Dr Penzi adds.
However, Dr. Penzi points out that essential oils have biologically active components and may be toxic. “Oils with high concentrations of aldehydes and phenols may cause skin irritation,” she says.
“Essential oils containing high concentrations of ketones should be used cautiously in pregnant women and infants.”
Rosemary oil can also cause allergic or irritant contact dermatitis. So be on the lookout if you notice anything out of the ordinary going on with your scalp or hair. If you experience any irritation, stop using it.
Even if you’re not seeing any negative side effects, be wary of how often you’re using it. “When used in excess, rosemary oil can make thinner hair look greasy and feel weighted,” Dr Camp notes.
How Long Does It Take To See Results From Using Rosemary Oil On Your Hair?
Don’t expect to wake up in the morning with longer, fuller hair. Nothing works overnight and progress can be slow—but don’t give up. “Keep in mind that hair changes, in general, are slow. It will take a minimum of three to six months before seeing any noticeable results,” Dr Penzi adds.
How To Use Rosemary Oil On Your Hair
Rosemary oil can be used as a stand-alone treatment. Where you apply it should depend on what you’re struggling with. “When used to treat hair loss, it should be applied directly to the scalp,” says Dr Camp. “When used for treating damaged hair, it should be applied to the hair.” Take a few drops and massage it right into your scalp to promote blood flow.
Dr Garlapati recommends leaving it on for at least ten minutes and using it daily. Alternatively, a few times a week is fine. Dr Penzi advises applying it at night and washing it out in the morning.
You could apply the pure oil directly to the scalp. Or, you could put some rosemary oil in your shampoo and let it sit on your scalp for a few minutes.
It can also be added to a “carrier oil, like coconut or olive oil, to dilute it,” adds Dr Camp. Also, BTW: there are no known ingredients that interfere with rosemary oil. Dr Penzi says you shouldn’t worry about using it alongside other products that might be in your haircare routine.
And if you don’t feel like using a bottle of essential oil from your local health food store, you can pick up hair products that contain rosemary oil too. Happy moisturizing.
The Advanced Hair Formula, blending herbs, amino acids and minerals, promotes healthier hair, while rosemary and mint oils boost circulation for faster, thicker growth.
This product combats thinning hair, promoting growth and volume. Rosemary stimulates circulation, stonecrop and horseradish extracts deter microbes and reduce inflammation.
Rosemary, Argan, Castor oil and Nettle herbs combine for a powerful, versatile blend. This product restores, strengthens and tames hair, promoting growth and moisture.