Hair loss, whether brought on by stress or genetics, is a pain point that sends many of us on a lengthy and costly journey toward healthy, luscious strands. Hair oils can give an additional layer of reinforcement to fend off dryness, while hair growth shampoos and rinse-out conditioners may help to clean and strengthen the hair thoroughly. If you've already embarked on this journey, you'll be well aware that rosemary oil is boasted some impressive anecdotal results, but is this seasoning-turned-scalp saviour all it's cracked up to be when it comes to the science?
Although likely best known as a savoury addition to your favourite dishes, rosemary is believed to have plenty of aromatherapeutic and beauty benefits, too. When it comes to hair growth, TikTok and Instagram have certainly hyped it up. We turned to the experts decipher the facts and fiction when it comes to rosemary oil for hair growth.
What Is Rosemary Oil?
Native to the Mediterranean region, rosemary oil is 'a pale liquid oil from the rosemary plant which has an herbaceous aroma,' says cosmetic chemist Ginger King. 'It’s often used in perfumes, skincare, and haircare as an antioxidant, anti-inflammatory, and antimicrobial ingredient.'
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How Can Rosemary Oil Benefit The Hair?
So, can rosemary oil help with hair growth? Some experts say yes, but it's important to note that current research is lacking.
'The rosemary plant contains carnosic acid, which is known to heal nerve damage, tissue damage, and improve cellular turnover,' says Marnie Nussbaum, MD, FAAD, a board-certified dermatologist. 'Therefore, it encourages nerve growth and improves blood circulation. The reason blood circulation is so important to hair growth is that without a proper blood supply, the follicles do not get the nutrients they need to grow the hair, and they can die off.'
There's also some indications that it can be useful for aiding irritation, when used in stable formulations and correct dosages. 'The rosemary plant in essential oil form is known to boast anti-inflammatory properties,' adds Ope Ofodile, MD, MPH, a board-certified cosmetic and medical dermatologist at Dermatology and Surgery Specialists of North Atlanta. However, note that when used improperly or excessively, rosemary oil can trigger increased scalp irritation, so it's important to consult a medical professional before trying it on yourself.
Anecdotally, social media users have witnessed some impressive results, such as strengthened, hydrated hair that grew longer due to a reduced frequency in breakage. It's important to note, however, that research is in its infancy, and you're far better speaking to a trichologist for medical advice before attempting herbal elixirs at home.
'If you are concerned you are losing your hair, I recommend seeing an expert – either a certified trichologist, or a dermatologist with an interest in hair loss – to find out what type of hair loss you have and what is causing it. There are many types of hair loss, and different possible causes – and each requires a different treatment approach,' says Anabel Kingsley, Consultant Trichologist.
An important caveat if you are planning to try it: 'Rosemary oil must be used sparingly because overexposure can be irritation on the skin,' says hairstylist Matt Newman.
How Long After Using Rosemary Oil Should Someone Expect To See Results In Hair Growth?
Not all hair will magically transform into Rapunzel-length upon using rosemary oil, as it depends on the person’s reaction to it. As with any topical hair treatment, be prepared to play the waiting game if longer hair is your goal. King says, 'There is limited study to prove its effectiveness, but it takes more than six months [of use] to see results.'
Who Can Use Rosemary Oil?
'Rosemary essential oil can be used on any hair type because the benefits target the hair follicle, not the hair strand,' says Newman. 'It is safe to use on colour-treated hair, especially because its main use should be directly on the scalp.'
However, if you have sensitive skin and are unsure how your scalp skin may react, first talk to your dermatologist about integrating the oil into your routine. Newman recommends doing a small patch test first and waiting 24 hours to see if any irritation occurs. 'Also, when applying to the scalp, tilt your head backward to avoid any oils dripping into your eyes.'
Also, 'There is no data regarding use in pregnancy or breastfeeding; therefore, I would avoid it if possible,' advises Dr. Nussbaum.
What Are The Side Effects Of Using Rosemary Oil For Hair?
The physical weight of the oil could interfere with your style. Newman says that for people with thin or fine hair or a sparse density of hair, the oils can make the hair look greasy and weighed down. 'If this is the case for you, try using the product as a pre-shampoo treatment reserved for days when you will be using a clarifying shampoo on your hair.'
It's also important to note that it can cause irritation, so always use a professional formula over a homemade blend. 'Compounding products at home that you apply to your scalp, which is skin, carries the risk of scalp irritation,' says Kingsley.
How Often Should I Put Rosemary Oil In My Hair And Can I Leave It In Overnight?
While some sources recommend using a carrier oil to dilute rosemary oil, you're far safer opting for a tested, professional formula that does the chemistry for you. 'It is safe to apply 1-2 times a week consistently to notice a difference,' says trichologist Hannah Gaboardi.
Although rosemary oil is not harmful, James warns against leaving it in hair overnight. 'Leaving any kind of oil on the scalp for a prolonged period of time will upset the microflora of the scalp,' he says. 'This can cause itchiness and redness, and it applies to all oils—not just rosemary oil.'
If you have very fine hair or an oily scalp, James advises using rosemary oil once a week as a scalp treatment and washing it out of hair immediately to avoid any greasiness.
Meet the experts
Ginger King is a New Jersey-based cosmetic chemist.
Dr. Marnie B. Nussbaum is a board-certified dermatologist specializing in non-invasive aesthetic rejuvenation.
Dr. Ope Ofodile is a board-certified cosmetic and medical dermatologist at Dermatology and Surgery Specialists of North Atlanta.
Dr. Gaby Longsworth, Ph.D. scientist, certified hair practitioner, and owner of the blog Absolutely Everything Curly.
Penny James is a trichologist and founder of the Penny James Salon Trichology Center.
From: ELLE US
Sam Peters
Senior Fashion & Luxury Commerce Editor
Sam Peters is the Senior Fashion and Luxury Commerce Editor at Hearst Magazines, where she edits and writes across Harper’s Bazaar, ELLE, Esquire, and more. She has nearly a decade of experience covering style, beauty, and home interiors, with bylines in numerous other major publications including Women’s Wear Daily, Pop Sugar, and Real Simple. She has reported on everything from cutting-edge skincare brands to fashion’s brightest emerging talents, while logging in hundreds of hours researching and testing products and consulting leading experts to uncover the best items on the market. In 2024, she co-launched ELLE’s first-ever advisory board—featuring over 45 top authorities in beauty, wellness, and medicine who ensure that ELLE’s content is of the highest quality and integrity. When she’s not poring over a beauty formula’s ingredients list or curating the chicest designer finds for a story, you might find her surfing in the Rockaways or re-watching episodes of Sex and the City.
Nerisha Penrose
Beauty Commerce Editor
Nerisha Penrose is the Beauty Commerce Editor at ELLE.com. Prior to joining the team, she was an Editorial Fellow at ELLE.com. In her current role, she helps lead coverage on makeup, skin care, hair, and fragrances. With over six years of experience in the world of beauty editorial, Nerisha enjoys delving deep into the complexities of fragrance notes, hunting for the best fixes for acne-prone skin, and advocating for daily sunscreen use. She regularly researches and tests the latest products, consults beauty professionals (including our Beauty Advisory Board) to determine the best expert-approved formulas to recommend, and conducts interviews with luminaries across the industry. Nerisha received her bachelor’s degree in Communication and Media Studies from Temple University before joining the editorial teams at Nylon and Billboard. In 2020, she co-launched our popular franchise The State of Black Beauty, an ongoing exploration of—and destination for—beauty at the intersection of Black culture.
