How To Use Rosemary Oil To Grow Thicker, Healthier Hair, According to Experts

Whether you’re currently experiencing hair loss, or you’re simply looking to promote healthy, thriving hair, you’ve probably come across the very trendy ingredient that is rosemary oil by now (looking at you, BeautyTok). This natural ingredient shows great promise for promoting hair growth, and it’s no wonder it has become so popular over the last year or so.

Hair loss is an extremely frustrating problem that affects people of various genders, ages, and ethnicities, as noted by Keka Heron, a master hairstylist and trichologist. Male and female pattern hair loss affects some 80 million people in the United States alone, adds Alan J. Bauman, MD, founder, CEO, and medical director of Bauman Medical Hair Transplant & Hair Loss Treatment Center. “It’s commonly associated with men, but women are significantly impacted as well,” says Dr. Bauman. “Research indicates that up to 40% of women experience hair thinning by age 50.”

On your journey to healthier hair, it makes sense that you would want to first look to natural remedies rather than resorting directly to costly and invasive procedures such as hair transplants. Of course, though, when trying any natural ingredient, you risk it not being as effective or experiencing side effects. It’s always a good idea to consult with an expert, such as a trichologist, before embarking on a treatment plan. But, in the meantime, we enlisted three hair experts to help us make sense of using rosemary oil for hair growth: Does it actually work? How do you use it? Find out everything you need to know below.

Does Rosemary Oil Promote Hair Growth?

The most pressing question when considering rosemary oil for hair growth is, well, does it work? While more research is needed to prove its effectiveness adequately, the ingredient shows great promise. In particular, BosleyMD trichologist Gretchen Friese cites a study published in SKINmed Journal, which showed no significant difference between the effectiveness of rosemary oil and minoxidil (a medication often prescribed for treating pattern hair loss) in increasing hair count in patients with androgenetic alopecia.

As for why rosemary oil is being touted as a potential remedy for hair loss, it’s based on a handful of compounds that may promote hair growth, including ursolic acid, carnosic acid, and rosmarinic acid. “Rosemary oil contains ursolic acid, which helps to increase circulation to the scalp and help promote hair growth,” explains Friese. “It is also thought to be beneficial to hair because it can reduce excess oil, soothe an itchy scalp, and make hair shiny and silky.”

Dr. Bauman explains that carnosic acid is a phenolic compound in rosemary oil with various hair growth-promoting benefits. “It has potent antioxidant properties, which help protect cells from damage by free radicals,” the expert explains. “In terms of hair growth, carnosic acid can stimulate microcirculation in the scalp, enhancing blood flow to hair follicles. This improved circulation can deliver more nutrients and oxygen to the follicles, potentially promoting healthier and stronger hair growth.” Dr. Bauman caveats that, though this compound may help with hair loss symptoms, it doesn’t address the underlying factors that lead to it. Rosmarinic acid, meanwhile, shows potential for regenerating hair growth, according to a 2018 study.

Dr. Bauman stresses that research on the potential for rosemary oil to promote hair growth and treat hair loss is still very limited and that you should take any trend like this one with a grain of salt. “Results can vary from person to person, and there is no replacement for clinically accepted first-line treatments,” he says. “Before considering rosemary oil or any alternative treatment, it's a good idea to consult with a certified trichologist or ABHRS board-certified and IAHRS-accepted hair restoration physician.”

However, in summary, Dr. Bauman lists the following as potential benefits of rosemary oil for hair growth, thanks to its antioxidant, anti-inflammatory, antifungal, and antibacterial properties: It may help with “lice, hair shedding, dryness of the hair, sebum production, scalp dryness, dandruff, and itchy scalp."

How to Use Rosemary Oil for Hair Growth

If you’re interested in trying rosemary oil for hair growth, here’s what you need to know before you start.

Safety Precautions

Before you start, there are a few precautions to safely use rosemary oil.

• Dilution: Rosemary oil is an essential oil that is too highly concentrated to use on the undiluted scalp—it can potentially cause skin irritation or allergic reactions. Therefore, “you should dilute it with your favorite carrier oil in a 2:3 ratio,” says Heron (you can also reduce the proportion of rosemary oil at first if you have a sensitive scalp or prefer to stay extra cautious). “My favorite carrier oils are jojoba and sweet almond,” adds Heron. You can also use coconut or grapeseed oil here.
• Patch testing: When using any new ingredient on the skin or scalp, it’s important to patch test it first to avoid any unwanted side effects. “Conduct a patch test before using rosemary oil to ensure you don’t have an allergic reaction,” says Dr. Bauman. “Apply a small diluted amount to a patch of skin and wait 24-48 hours to check for any redness, itching, or swelling.” Testing on the back of your scalp may be a good idea.
• Pregnancy and breast-feeding: Avoid using rosemary oil if you’re pregnant or breastfeeding, says Dr. Bauman, as there are potential health risks.
• Pre-existing conditions: “If you have underlying scalp or health issues, consult with a trichologist or hair restoration physician before using rosemary oil,” says Dr. Bauman. Heron also cautions that rosemary oil shouldn’t be applied if you have open sores or if your scalp feels tender.
• Using rosemary oil as part of a balanced lifestyle: While topical ingredients like rosemary oil can potentially help promote hair growth, it’s also important to make lifestyle choices that support it. Dr. Bauman recommends following a diet that’s high in protein, biotin, vitamin D, zinc, and iron, avoiding alcohol, tobacco, and drugs, exercising regularly, getting adequate sleep, and managing stress through practices like meditation or yoga. The expert also recommends considering professional hair and scalp treatments to complement your hair growth journey and treat underlying factors and symptoms of hair loss.

Application Methods

There are two commonly used application methods for rosemary oil: scalp massage with the combo of carrier and essential oil or mixing the diluted oil with shampoo or conditioner.

• Scalp Massage: You can incorporate rosemary oil into your hair care routine with a scalp massage. To do this, “mix five drops of rosemary essential oil with one teaspoon of carrier oil, and massage evenly into your scalp after you have shampooed and conditioned your hair,” says Friese. “You can use a scalp massager if you’d like—they are great for creating circulation at the scalp.” After massaging, you can rinse the oil out after letting it sit for a minimum of 5 to 10 minutes or leave it to work its magic overnight. “If you are going to leave the oil in your hair, make sure to use a pillow case that you don’t mind getting oily or put a towel on your pillow before laying down,” says Friese. “Also, take special care not to get it in your eyes.”
• Mixing With Shampoo or Conditioner: Another easy way to incorporate rosemary oil into your hair care routine, which you may find more approachable, is to mix in a couple of drops of pure rosemary oil with your shampoo or conditioner while it’s in your hand. “I recommend using a clarifying shampoo first and then adding the oil to your regular shampoo or conditioner,” says Friese. “Because you generally don’t put conditioner on your scalp, putting it in your shampoo is better, but you can do both.” You should then use your shampoo and/or conditioner as normal, but let it sit on your scalp for a few minutes before rinsing, notes Dr. Bauman.

Frequency

The jury is still out on the best cadence for rosemary oil usage. Friese recommends using rosemary oil in your hair care regimen once a week or once every two weeks, while Dr. Bauman recommends using it two to three times a week. If you’re unsure what frequency suits you best, it’s never a bad idea to consult a hair care professional beforehand. “Visible results can vary; some individuals may notice improvements within a few months, while for others, it might take longer,” says Dr. Bauman. “Consistency and patience are key when using natural treatments.”

Rosemary oil is a low-risk natural option for promoting hair growth and preventing (or reversing) hair loss. Current research on its efficacy is promising, though more is still needed. If your hair loss is significant, it’s best to first consult with a certified trichologist or hair restoration physician who can help you devise a more comprehensive plan for achieving extra healthy hair, but if you’re looking for a bit of a boost, rosemary oil is a great addition to your hair care—alongside a balanced lifestyle, of course.