Does Rosemary Oil Really Help With Hair Growth? Here's What Experts Have To Say
Dudaeva / Getty Images
Medically reviewed by William Truswell, MD
Rosemary is an herb which typically grows near the Mediterranean sea and Himalayan regions. It is known for its anti-inflammatory, antioxidant, and antimicrobial properties.
Although rosemary oil hasn’t been studied extensively as a hair growth product, some studies have found that it may help with hair growth when applied topically to the scalp. This may be due to rosemary’s antioxidant qualities, and because it can increase blood flow to the scalp.
How Rosemary Oil Helps With Hair Growth
Rosemary (Rosmarinus officinalis L.) is an herb that has been used in herbal medicine to treat conditions like headaches, insomnia, and depression. In particular, carnosic acid, a component of rosemary, is known to have antioxidant and anti-inflammatory qualities.
According to Carmen Castilla, M.D., New York City-based dermatologist and a clinical instructor at Mount Sinai, there is some evidence that rosemary oil may help with hair growth. “Rosemary oil is an antioxidant and it also can increase capillary perfusion (meaning blood flow) to the scalp which may be the reason it is able to help with hair growth,” Castilla told Health. “The increase in capillary perfusion is very similar to the mechanism of action of minoxidil, a well established treatment option for hair growth.”
What Studies Say
Studies about rosemary oil for hair growth are limited at this time, and many of the existing studies have been on animals, not humans. For example, one study found that topical application of rosemary oil improved hair growth in mice who were experiencing hair growth issues as a result of testosterone treatment.
An old study from 1989 found that a combination of essential oils (rosemary, thyme, lavender, and cedarwood oil) induced significant hair growth when applied to the scalp on a daily basis. However, this study is old and didn’t isolate rosemary oil specifically as a hair loss treatment.
There is one more recent, promising study that looked at the effects of rosemary oil on hair growth. This study was focused on using rosemary oil to treat male pattern baldness. It compared the effects of using rosemary oil with using minoxidil, a common hair growth treatment which is known to be effective.
Patients were either given rosemary oil or minoxidil 2% and used each treatment for a six month period. The study found that both treatments were equally effective at regrowing hair. Additionally, the study found that people who used rosemary oil were less likely to experience an itchy scalp than people who used minoxidil.
Though encouraging, Dr. Castilla says there are some flaws in this study. First of all, the recommended minoxidil dose for men is 5%, but this study used a 2% dose, which is lower than what is usually recommended. Moreover, it was a small sample size and there was no placebo group. “It is difficult to draw definitive conclusions about the true efficacy based on this one study,” Dr. Castilla said.
Related: How to Take Care of Your Scalp and Why It Matters
How to Use Rosemary Oil for Hair Growth
First of all, it’s important to visit your healthcare provider if you are experiencing hair loss. “Jumping straight to supplements or a viral TikTok trend can delay your underlying diagnosis and lead to permanent hair loss,” Dr. Castilla said. “Hair loss can be a sign of an internal disorder or medical problem and this needs to be addressed for the hair loss to improve.”
If you decide to use rosemary oil for hair loss, Dr. Castilla shared some tips:
Don’t place rosemary essential oil directly on your scalp, as this can cause irritation.
Instead, mix the essential oil with a carrier oil such as jojoba oil.
You can also purchase premade formulations containing rosemary oil.
Make sure to massage the oil into the scalp, as having it stay on your hair isn’t going to do anything besides make your hair greasy.
Start slow, trying the oil a few times a week to ensure that it isn’t irritating your skin.
If it isn’t causing irritation, you can increase the frequency of use.
When using, let it sit on your scalp for a few minutes, and then rinse it out.
Related: How to Make Your Hair Grow Faster
Other Benefits of Rosemary Oil
Rosemary, in both oil and plant form, has other potential health benefits. Here’s what to know:
There are indications that rosemary may be helpful in treating depression, epilepsy, neuropathic pain, and Parkinson’s disease. However, the evidence we have is based on studies done with mice.
Inhaled rosemary oil (such as in aromatherapy), has shown promise in boosting mood, improving academic performance, and decreasing cortisol levels.
One study found that rosemary powder enhanced memory in older adults.
A small study found that taking rosemary capsules (300 milligrams dried rosemary leaves) was helpful in reducing withdrawal symptoms after stopping opium. Researchers hypothesized that rosemary may be helpful in managing other types of opioid withdrawal symptoms.
There is evidence that topical rosemary application may be helpful for people who live with chronic pain.
Risks and Side Effects of Rosemary Oil
It’s important to note that herbal supplements are not regulated or standardized by the FDA. You should always consult with your healthcare provider before starting a supplement, and you shouldn't take more than the recommended dose.
Shab Caspara, trichologist and founder of Leona, said that her one concern with using rosemary oil for hair growth is that it has the potential to irritate the scalp, especially when it’s not mixed with a carrier oil or used as part of a pre-formulated product.
“I don’t recommend making homemade scalp products using essential oils as they are super concentrated and can sensitize the scalp very easily if not monitored or formulated carefully,” she said. “Incorrectly applying naturally potent oils to your scalp can irritate, inflame and seriously harm the scalp and eventually the hair follicle itself.”
Dr. Castilla agreed that irritation of the scalp is the main concern with rosemary oil. However, besides the potential to cause irritation, Dr. Castilla said that it is unlikely to have other significant side effects. She notes that it hasn’t been studied in pregnant individuals, so she would recommend refraining from using it if you are pregnant.
Related: How Scalp Atopic Dermatitis Differs From Other Skin Conditions
A Quick Review
You may have heard of rosemary oil as a natural, simple way to increase hair growth. Limited studies have found that rosemary oil may be an effective way to treat hair loss, and one study found that rosemary oil was about as effective as minoxidil at encouraging hair growth.
Experts recommend that if you choose to use rosemary oil for hair growth that you use a pre-formulated product containing rosemary oil or mix it into a carrier oil. Rosemary oil is unlikely to have serious side effects but experts warn that it can potentially cause skin irritation.
Frequently Asked Questions
How long does it take for rosemary oil to grow hair?
Any type of hair growth enhancing product takes a few months for results and you can expect a similar timeline for rosemary oil. “Since only the new growth of hair will show signs of improvement and not the existing hair on the head, you will need at least three months before you can see a visible difference in the quality of your hair,” said Caspara.
Is it OK to leave rosemary oil on overnight?
You should only leave rosemary oil on overnight if you are using a professionally formulated product that contains rosemary oil, Caspara advised. It's strongly advises against leaving a homemade rosemary oil concoction on your scalp for more than 20 minutes, as doing so can cause irritation.
How often should I use rosemary oil for hair growth?
Dr. Castilla recommended starting gradually with rosemary oil, and only using it a few times a week at first to ensure it isn’t going to cause irritation. You can increase frequency after this. As for how many days per week to use rosemary oil, you should consult with a physician or a certified trichologist.
For more Health news, make sure to sign up for our newsletter!
Read the original article on Health.
