25-06-2025
Thinning hair? Try these 9 rosemary oils for hair growth, recommended by dermatologists
Rosemary oil for hair growth quick picks
Editor-favorite scalp and hair oil: JVN Complete Pre-Wash Scalp Oil
Quick pre-shower treatment: Kiehl's Magic Elixir Scalp and Hair Oil Treatment
Affordable and clean ingredient oil: Plant Therapy Rosemary & Castor Hair Oil Whether you're concerned about hair thinning or hair loss, or just wish your hair had a healthier look and feel, some quick online research might have led you down the path of rosemary oil treatments. Derived from the same plant that gives us fragrant herbs for cooking, rosemary oil is regarded as a powerful natural remedy due to its antioxidant-rich, anti-inflammatory and antimicrobial profile that many people on the internet claim helps boost hair growth. But with so many ill-sourced beauty claims flying around online these days, we sought out dermatologists to better understand what benefits rosemary oil can bring to your scalp and whether it's worth adding into your hair care routine.
Mielle Organics Rosemary Mint Scalp & Hair Strengthening Oil
Both a viral product and a favorite of board-certified dermatologists Dr. Marisa Garshick and Dr. Dara Spearman, this Mielle blend of rosemary, castor and mint oils is also infused with biotin, which Spearman said helps hydrate hair, improve dry scalp symptoms and address split ends.
Cliganic Organic Rosemary Essential Oil
You can make your own hair oil blend at home by diluting a few drops of a rosemary essential oil, like this Cliganic one, into a more neutral carrier oil, like jojoba or argan. Dr. Michele Green, a board-certified cosmetic dermatologist in New York City, said that pure rosemary essential oil is very potent, so it's important to dilute it by adding two to three drops into two tablespoons of a carrier oil before applying it to your hair and scalp.
Nature Spell Natural Rosemary Oil
This natural hair oil that CNN Underscored beauty and fashion editor Sophie Shaw recommends has a simple, five-ingredient formula. The rosemary oil is the star of the show, and it comes pre-diluted in sweet almond and sunflower oils. She likes to use it as a pre-shampoo treatment on her scalp, massaging the oil in at least 30 minutes before showering.
Kiehl's Magic Elixir Scalp and Hair Oil Treatment
With a blend of avocado and rosemary oil, this Kiehl's treatment only needs to be left on for 10 minutes to fully work its magic. Designed to help increase your hair's moisture and shine, this treatment is safe for all hair types, even for those with fine hair who might worry about oils leaving behind a greasy look or feel.
Weleda Condition & Shine Hair Oil
You can use this deep conditioning oil on wet or dry hair to improve shine, restore moisture and soften split ends. According to board-certified dermatologist and founder of SmarterSkin Dermatology Dr. Sejal Shah, the combination of rosemary oil with clover and burdock extracts in this formula helps to condition the hair and scalp while also encouraging growth.
The Nue Co. Supa Thick Scalp Serum
Spearman likes this thickening scalp serum from The Nue Co., which features ingredients like rosemary leaf and peppermint oil to stimulate circulation, as well as clary sage oil to strengthen the hair shaft.
Briogeo Scalp Revival Rosemary Pre-Wash Scalp and Hair Oil
Suitable to use pre-wash or as an overnight treatment, this Briogeo blend is made with rosemary oil to help scalp circulation, as well as castor oil for replenishing moisture. Safe for use on all hair types and textures, this oil is also designed to be 'tingle-free,' so even those with ultra-sensitive scalps can benefit from the gentle formula.
JVN Complete Pre-Wash Scalp Oil
We tested a whole bunch of products from 'Queer Eye' star Jonathan Van Ness' hair care line when it launched in 2022, and this scalp oil was among our editors' favorites. CNN Underscored newsletter editor Lindsey Smith said this oil — which is made with rosemary extract — was a game changer for soothing her itchy and dry scalp, while other editors noted that it made their hair more manageable to style daily.
Plant Therapy Rosemary & Castor Hair Oil
Focused on making products with clean and simple formulas, Plant Therapy created this oil blend with only three ingredients: rosemary, castor and almond oil. Gentle enough to leave on your scalp overnight, this blend can also be used to style dry hair and add extra shine to your ends. 'Rosemary oil can help condition and strengthen the hair and also works to reduce damage and breakage, making the hair appear stronger,' said Garshick. 'Additionally, some studies have shown that rosemary oil can help to boost hair growth; it is thought to help improve circulation in the scalp, which, by increasing blood flow, may help stimulate hair growth.'
Hair oils, in general, can help restore moisture to dry or damaged hair, providing vitamins and nutrients that aid in limiting shedding and breakage. These oils, however, do not directly create hair growth. Double board-certified dermatologist at Medical Dermatology & Cosmetic Surgery Dr. Brendan Camp said that hair oils help create good scalp conditions, which can improve the overall health of the scalp skin and hair follicles.
Green said the antioxidant and anti-inflammatory properties in rosemary oil help protect hair from oxidative stress and environmental aggressors like UV radiation and pollution, thus aiding in preventing hair loss. Green also said that by boosting circulation and helping increase blood flow to the scalp, rosemary oil can allow more oxygen and nutrients necessary for hair growth to be delivered to the hair follicles.
This increased blood flow — as well as the antioxidant-rich, anti-inflammatory and antimicrobial properties — is potentially the reason rosemary oil can help with hair regrowth. These mechanisms are similar to the ones by which minoxidil, the main ingredient in Rogaine, also works, Shah said.
You should take a slight pause of caution before slicking anything to your scalp. Spearman said allergic reactions and scalp irritation are the most common risks when using rosemary oil. She added that the safety of rosemary oil use during pregnancy has not been well-established, so you may want to consult with a medical professional before adding something new into your routine if you're expecting.
While you can opt for prescription medications to help treat hair loss, some people prefer the affordability and availability of natural alternatives like rosemary oil, which are also made without synthetic chemicals. If you're experiencing hair loss that does not respond to over-the-counter treatments or is negatively impacting your quality of life, Spearman recommends you consult a board-certified dermatologist for help.
There's still limited evidence to support the efficacy of rosemary oil for hair loss and regrowth, but there have been multiple studies that demonstrate its potential.
'One study found that rosemary oil stimulated hair growth in mice who had hair loss due to testosterone treatment, and another found that rosemary oil was as effective as minoxidil 2% for regrowing hair in men with male pattern hair loss,' Shah said, but noted that we need more data before we can make any definitive conclusions about rosemary oil's effectiveness.
Depending on the formulation, you can leave rosemary oil on your scalp for anywhere from a few hours to overnight, but Green said you should follow the application instructions for the product you're using.
'[Rosemary oil] can also be mixed into your shampoo or hair creams as a part of your hair care routine, but when using rosemary on its own, it's important to dilute it with a carrier [oil] such as jojoba, coconut or argan oil before application,' Green said. If you want to save your fingers from getting greasy, a scalp massager can help both to distribute hair oil on dry hair and ensure you get a nice, deep clean when you want to shampoo oils away in the shower.
As with other hair treatments, it can take several months before you see any noticeable improvements from using rosemary oil, but staying consistent is key for getting results. If you have sensitive skin, Garshick said you should patch test some rosemary oil on a small area of your skin to check for any reactions before applying it all over your scalp.
You can also utilize rosemary oil in other parts of your grooming routine. Spearman said rosemary oil is commonly used for beard hair growth, though added that as with hair on the head, it should still be diluted with a carrier oil before use. Rosemary oil's effectiveness in helping with the growth of eyebrow hairs or other body hairs has not been as well-documented, so if you're looking to use it for things other than your scalp or beard, Spearman said the efficacy may vary.
The following FAQs have been answered by board-certified dermatologists Dr. Dara Spearman and Dr. Brendan Camp.
Can rosemary oil be left on hair overnight?
Can rosemary oil be left on hair overnight?
Though Camp recommends massaging a diluted mix into your scalp and only letting it sit for 30 minutes before washing out, Spearman said that rosemary oil is safe to keep on overnight if it's diluted with a carrier oil. To apply, part your hair and use either your fingers or an applicator to gently spread and massage the diluted oil over your scalp.
Both Camp and Spearman said it's best to apply rosemary oil one to two times per week to see how your scalp responds and to allow the oil to work efficiently without causing excess buildup.
How long does rosemary oil take to grow hair?
How long does rosemary oil take to grow hair?
While you might notice softer, more hydrated and flexible hair within the first one to two weeks of using rosemary oil products, it can take months before you see any sort of hair growth. Camp said that because most people's hair grows slowly — around 0.5 inches per month — you'll need to use rosemary oil regularly for at least three to four months before deciding whether or not it's an effective treatment for you.
Spearman added that the amount of time it takes to see results varies from person to person, but generally, you'll see some progress after two to three months with consistent application and more significant results after about six months of regular use.
Is castor oil or rosemary oil better for hair growth?
Is castor oil or rosemary oil better for hair growth?
Spearman said that rosemary oil currently has better data to back its claims for hair growth, while castor oil is thought to be better at improving strength and thickness in dry or brittle hair. Camp added that there is limited data overall to support the use of rosemary or castor oil for hair growth, so you could consider integrating both into your hair care routine to see which works best for you.
For this article, we consulted the following dermatologists to gain their professional insights.
Dr. Brendan Camp, double board-certified dermatologist at Medical Dermatology & Cosmetic Surgery
Dr. Marisa Garshick, a board-certified dermatologist in New York City
Dr. Michele Green, a board-certified cosmetic dermatologist in New York City
Dr. Sejal Shah, a board-certified dermatologist and founder of SmarterSkin Dermatology
Dr. Dara Spearman, board-certified dermatologist and owner of Radiant Dermatology Associates in Fort Wayne, Indiana
CNN Underscored has a team of writers and editors who have many years of experience testing, researching and recommending products, and they ensure each article is carefully edited and products are properly vetted. We talk to top experts when relevant to make certain we are testing each product accurately, recommending only the best products and considering the pros and cons of each item. For this story, associate editor Jillian Tracy consulted five dermatologists to better explain how rosemary oil can benefit your hair and scalp.
