I guess my TikTok algorithm senses that I have perpetually short, fine, thin hair because it’s constantly feeding me hair growth solutions. And honestly, I’ve tried everything to make my hair grow faster: hair growth vitamins, aloe vera for hair growth, castor oil scalp massages, rice water treatments—you name it. But the only thing I hadn’t yet tried? Rosemary oil for hair has hella anecdotal evidence from TikTokers (with a casual 205 million searches), as well as some potentially promising information from small-scale studies that compare its results to minoxidil which is the active ingredient in Regaine.
But unlike the previous methods I’ve tried, I decided to dig into the science behind rosemary oil for hair before potentially wasting my money on yet another scalp product. Here’s what dermatologist doctor Yoram Harth, certified trichologist Gretchen Oligee, and cosmetic chemist Krupa Koestline had to say about everything rosemary oil, like how rosemary oil works, if rosemary oil is safe for hair, and how often to use rosemary oil. Keep reading for all the details:
What is rosemary oil?
Rosemary oil is the oil that’s extracted from the leaves of the rosemary plant, which is native to the Mediterranean. Yup, it’s the same fragrant rosemary you season your veggies and cocktails with, which is why it’s considered an aromatic herb, like basil, lavender, and sage. Its fragrance is why it’s often used in perfume formulations, while its potential to help soothe your skin is why it’s often found in skincare and haircare products.
The terms “rosemary oil” and “rosemary essential oil” are often used interchangeably, says cosmetic chemist Krupa Koestline (note: Rosemary oil is not the same as rosemary extract, which has a completely different extraction process and tends to be gentler and less volatile). Sometimes, rosemary essential oil will already be pre-mixed with a carrier oil (like sweet almond oil or jojoba oil) because the essential oil is so potent on its own that it could potentially cause irritation.
Our favourite rosemary oil hair products
Larry King Hair Spoilt For Choice Hair Oil 100ml
Mielle Rosemary Mint Growth Hair Oil
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Faith In Nature Rosemary Conditioner – 400ml
Aveda Rosemary Mint Purifying Shampoo 250ml
Is rosemary oil good for hair growth?
Rosemary oil and/or rosemary extract is potentially good for hair growth, depending on who you ask and how seriously you take its limited evidence. One 2013 study conducted on mice showed that rosemary leaf extract was effective in helping to promote regrowth in hormone-related hair loss. Oligee and dermatologist Yoram Harth, MD, also point to a commonly cited 2015 study that compared rosemary oil extract to minoxidil when used on men with genetic androgen-related hair loss.
But why is rosemary oil good for hair growth exactly? Carnosic acid, one of the main ingredients in rosemary oil, is thought to potentially stimulate and heal nerve tissue, according to one 2010 study, which could possibly do the same to your scalp and help encourage hair growth. Dr. Harth explains that the other main ingredients of rosemary oil—α-Pinene, 1,8-cineole, camphor, and borneol—may all be beneficial for hair growth too, and points to “a 2017 study that noted these natural compounds might have anti-inflammatory, antifungal, antibacterial, antioxidant, and pain-reducing properties,” Dr. Harth says.
Rosemary oil is also thought to potentially boost blood flow to the follicle, thus encouraging healthier hair growth, and can also minimise cell-damaging free radicals with its strong antioxidant properties. Basically, there are a dozen things that rosemary oil can potentially, probably, and likely do for your scalp health, which is why it’s been a staple skincare ingredient for thousands of years.
Rosemary oils to try now
Nature Spell Rosemary Oil for Hair & Skin 150 ml – Rosemary Oil for Hair Growth – Treat Dry Damaged Hair to Target Hair Loss – Made in The UK
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PHATOIL Rosemary Essential Oil 100ML
Nikura Rosemary Essential Oil – 10ml
TOYHHO Rosemary Essential Oil
What are the side effects of rosemary oil on hair?
There are very few side effects of using rosemary oil on your hair and scalp, as it’s well tolerated by most skin and hair types. However, if you are pregnant or breastfeeding, talk to your doctor beforehand (camphor, which is found in rosemary oil, has some potential risks with pregnancy and hasn’t been widely studied).
Keep in mind, though, that there are always risks of contact dermatitis and irritation with any new topical skincare ingredient you try, especially when they involve botanical extracts. So test the oil on the back of your neck first and wait two to three days to see if you have any negative reactions before massaging it across your whole scalp.
Can you use rosemary oil for hair loss?
Yes, you can use rosemary oil for hair loss, as long as you manage your expectations. “Rosemary oil has been compared to minoxidil for its ability to improve circulation on the scalp and even encourage cellular turnover,” says Oligee, “which can both improve hair growth and help prevent hair loss,” Oligee says. Plus, rosemary oil has anti-inflammatory qualities that, over time, could potentially help prevent inflammation-based hair-loss conditions, like certain forms of alopecia, Oligee notes.
That being said, hair loss is multifaceted and could be caused by age, hormones, genetics, stress levels, your environment, or certain medications. This means it’s vital to see your doctor if you’re shedding more hair than average (which tends to be 50 to 100 hairs per day, FYI), as hair growth often requires a varied and robust approach.
How do I use rosemary oil for hair growth?
There are a few ways to use rosemary oil for hair growth, depending on the formula you’re using and the level of effort you’re willing to put in. If you’re using rosemary oil that’s already mixed with a carrier (like castor oil), you can drip two to three drops directly onto your scalp, then massage in. (FWIW, I like to use a silicone scalp massager to really ~get in there~, but feel free to just use your fingertips.) But if you’re using pure rosemary essential oil, you’ll need to dilute it first with either another oil or your shampoo.
But I’ll be honest: DIYing rosemary for hair growth can be tricky (Dr. Harth warns against using too much, which could possibly irritate sensitive skin), so it’s recommended you use a product that’s already formulated with rosemary oil and follow the manufacturer’s instructions, whether it’s a rosemary oil shampoo, a rosemary oil treatment, or a rosemary oil deep conditioner.
How long does it take for rosemary oil to grow hair?
It took six months for testers to notice hair growth in the 2015 study that compared daily rosemary oil scalp treatments to minoxidil. But remember: It’s not guaranteed you’ll see any hair growth results from rosemary oil, let alone over a specific time span. So if you don’t feel like waiting six months to see potential results, or you’re becoming increasingly worried about your hair loss, make an appointment with your dermatologist who can recommend faster, more effective treatments, like prescription minoxidil, custom-compounded formulas, injections, microneedling, light therapy, and/or oral medications.
Do you have to dilute rosemary oil for hair?
You don’t have to dilute rosemary hair for your hair if it’s already mixed with another oil (usually castor oil or jojoba oil). But, if you’re using a pure rosemary essential oil, yes, you should dilute it with a carrier oil, such as grapeseed oil or coconut oil, or in another product, like shampoo, instead of applying it directly to your hair or scalp. Why? Because essential oils are so concentrated, they can easily irritate your skin, leading to flaking, burning, and dryness.
Some more of our favourite rosemary oil products
AROMATICA Rosemary Scalp Scrub 5.82oz / 165g, Sulfate-Free, Silicone-Free, Vegan, Scalp Cleansing with Salt Granules, Invigorates and Exfoliates Scalp, Micro-Exfoliate
Mielle Organics Rosemary Mint Multi-Vitamin Daily Styling Creme For Curly Hair Definition, Paraben And Silicone Free, 240 ml, White
Pattern Scalp Serum
Aveeno Volumising Fresh Greens Scalp Soothing Mint, Cucumber and Rosemary Shampoo for Fine Hair 300ml
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Aveeno Volumising Fresh Greens Blend Shampoo
Can I apply rosemary oil directly to hair?
Rosemary oil can be applied directly to your hair strands (it won’t cause damage), but it should be massaged into your scalp if you’re looking for potential hair growth benefits. Just note that if you have fine hair, you’ll probably prefer to massage the oil in before bed, tie your hair up while you sleep, and then rinse the next morning with a clarifying shampoo to get rid of any greasy residue. Or, if you want to use it during the day, massage it on and pull your hair back into a sleek bun with a boar-bristle brush and a couple of hair bands to make the ~grease~ look purposeful.
If you’re working with type-4 hair or ultra-thick hair that never gets greasy, you have more flexibility in how you apply your rosemary oil. You can use it twice a day by massaging it into your scalp in the morning and then again at night, or just once a day if you have a sensitive scalp (and/or zero time).
Is it safe to use rosemary oil on hair every day?
For most people, it’s safe to use rosemary oil on your hair and scalp every day, says Dr. Harth, provided you patch-test first to confirm you don’t have any sensitivities. Oligee even recommends applying rosemary oil twice a day if you have high-porosity hair that soaks up oils and butters like a sponge, and if your scalp isn’t overly sensitive.
Keep in mind, though, that essential oils, even when mixed with a carrier oil, can be potentially irritating, so you might want to take it slowly at first (like two to three times a week). Plus, if you’re acne-prone or have an oily scalp, you’ll probably prefer to stick to once every couple of days to avoid potentially clogging your hair follicles, as well as having to wash your hair too frequently.
Is rosemary good for all hair types?
Yes, rosemary oil can be used for all hair types. But if you have fine, thin, or low-porosity hair (i.e. hair that doesn’t absorb ingredients well and products tend to just sit on top), you might experience oily roots or greasy ends with rosemary oil – and tbh, any hair oil.
Final thoughts
Turns out, rosemary oil for hair might be a great option to test out if you’re dealing with hair loss or thinning, as well as a dry, itchy scalp. While there are a few studies showing promise for rosemary oil and hair growth, more research needs to be done to definitively call it a proven hair growth treatment. But as is the case with most hair growth remedies, don’t expect results overnight. As great as a rosemary oil concoction might be for calming inflammation, it’s no magic hair cocktail – but hey, it might be worth a shot.
Meet the experts
- Krupa Koestline is a cosmetic chemist and the founder of KKT Consultants where she consults with brands on clean guidelines, as well as new and eco-friendly manufacturing processes.
- Yoram Harth, MD, is a board-certified dermatologist in San Francisco, CA. He’s also the founder and chief medical officer of MD Hair, a customised subscription hair growth treatment.
- Gretchen Oligee is a certified trichologist and hairstylist at Foushee Salon and Spa in Littleton, CO., US. She has expertise in hair loss, hair cutting, and hair colour.
Beth Gillette is the beauty editor at Cosmopolitan, where she covers skincare, makeup, hair, nails, and more across digital and print. She can generally be found in bright eyeshadow furiously typing her latest feature or hemming and hawing about a new product you “have to try.” Prior to Cosmopolitan, she wrote and edited beauty content as an Editor at The Everygirl for four years. Follow her on Instagram for makeup selfies and a new hair ‘do every few months.
Brooke Shunatona is a contributing writer for Cosmopolitan.com.
