What Is Rosemary Oil?

WebMD

13-06-2025

You might be familiar with rosemary as a flavorful, aromatic cooking herb. Rosemary essential oil is a concentrated extract from the plant. It comes from the spiky leaves and tiny blue flowers of the evergreen bush Rosmarinus officinalis L.
Originally grown beside the Mediterranean Sea and south of the Himalayas, rosemary has deep roots as a folk remedy for migraine, pain, insomnia, emotional imbalances, and more. Today its science-proven benefits include helping boost memory and learning, coaxing hair growth, and easing pain.
Studies have found rosemary extracts have bioactive properties, which means they can help your body fight bacteria, funguses, and free radicals and calm swelling. The rosemary plant is hardy, too – it can grow where it's hot and dry and in many types of soil.
Are There Different Types of Rosemary Oil?
There are four main chemotypes – chemical traits that make them different from each other – of rosemary oil, according to Robert Tisserand. He's an international speaker and educator on the science, benefits, and safe uses of essential oils through his organization, the Tisserand Institute. They are:
Camphor
Cineole
Pinene
Verbenone
'The one used in hair growth trials is the cineole type, and this is also the one most commonly sold,' he says. 'If the label does not give the type, it will be the cineole type.'
Is Rosemary Oil Good for Hair Growth?
Yes. Studies have found rosemary oil can help spur hair regrowth as well as Rogaine, aka minoxidil, the drug famous for helping regrow hair. Rosemary oil also doesn't make your scalp as itchy as the over-the-counter med does. Many people appreciate having a natural alternative to a drug, too.
Rosemary oil can help your hair and scalp in other ways, too. Because it helps calm inflammation on your scalp, it can curb dandruff.
How do I use rosemary oil for my hair?
You'll be treating your scalp, not your actual hair, when you use rosemary oil to boost hair growth. You can safely apply rosemary oil once a day, Tisserand says. It usually takes two to three months to see results. To help your skin absorb the oil, massage your head with your fingertips for 30 seconds after every application.
How long should I leave on rosemary oil?
You can leave it in or wash your hair with shampoo two hours after application. 'If your hair is very oily, apply the shampoo before using any water,' Tisserand advises.
How do I prepare the rosemary oil for this treatment?
'It's important that the rosemary oil is diluted before use,' says Tisserand. 'This is mostly for safety reasons – to avoid irritation – but also because most of it will simply evaporate, and you want it to go into your scalp.' He advises using 5%-10% rosemary oil to 90%-95% of what you're going to use to dilute the essential oil with. (You can figure out how many essential oil drops to use per ounce of diluent using a chart like this one by the National Association for Holistic Aromatherapy.)
Two good diluent choices are castor oil and fractionated coconut oil, in which certain fatty acids are removed to make coconut oil more stable and easily absorbed into your skin. Fractionated coconut oil also is less greasy than castor oil.
'If you want a non-greasy product, look for a non-fragranced gel,' Tisserand adds. 'Don't go for aloe vera gel, as this is 99% water. Go for aloe jelly, which has other ingredients that thicken it to gel consistency.'
Is castor oil or rosemary oil better for hair growth?
'There is a very longstanding tradition of using castor oil for hair growth, but so far there is no supporting evidence,' says Tisserand. 'Of course you can use both, since castor is a fatty oil and rosemary is an essential oil.'
What are the side effects of using rosemary oil for your hair?
Rosemary is linked to heavier menstrual flow and potential miscarriage. If you are pregnant or breastfeeding, you are advised against using rosemary oil. But it's OK to eat rosemary in plant form to enhance your food.
More Benefits of Rosemary Oil
Fend off bugs
Does rosemary oil work as a bug repellent? 'Indeed, it does,' says Tisserand. 'There are many different types of bugs, and rosemary is a good choice overall.' Repellent is a substance you apply to your skin to keep mosquitoes and other insects from biting you. An Indonesian study found rosemary oil diluted in a gel formula worked and lasted almost as long as store bought bug repellent that contained the chemical DEET.
Boost your brainpower
A U.K. study found exposure to rosemary essential oil was strongly related to cognitive tasks including subtraction and memory. Sometimes you might see rosemary oil suggested as a stress reliever. However, Tisserand says, 'Rosemary is one of the few oils that are stimulating rather than calming, so it's not an ideal choice for stress. Psychologically, rosemary oil is good for improving cognition, such as focus and memory.'
Ease body pain
Studies have found applying rosemary oil directly to your body can cut down frequency and intensity of musculoskeletal pain – that's pain in your joints and bones, muscles, ligaments, and tendons. Rosemary oil is also sometimes used to treat arthritis and boost blood circulation.
Make you feel happier
One study found people who received massages with rosemary oil felt more refreshed, cheerful, and alert than a control group that had massages with oil that didn't have rosemary.
Fight acne
A study of people with acne reported using rosemary oil in a topical gel improved not only their acne but their skin health as well, with minimal side effects. The people used the gel twice a day for four weeks. This study suggests rosemary oil has promise as a natural, safe alternative to acne drugs.
Does Rosemary Oil Have Side Effects?
Like most substances, you should take rosemary oil in the recommended dosage for the purpose you're using it for. Some people are allergic to it, too. If taken in large doses, rosemary oil can cause:
Spasms
Vomiting
Fluid in your lungs, known as pulmonary edema
Coma
Rosemary also isn't recommended for people who have:
Crohn's disease
High blood pressure
Ulcers
Ulcerative colitis
You should never take rosemary essential oil by mouth, as it can be toxic. When you see recipes that contain rosemary oil, they're referring to oil that has been infused with rosemary, which is a different preparation. You can find these types for cooking in grocery and natural food stores and culinary specialty stores.
Can You Make Your Own Rosemary Oil?
'Making your own essential oil is not easy, and even if you do manage to do this, chances are you will only end up with a few drops,' says Tisserand.
Where Can I Buy It?
'Rosemary oil is very easy to find,' Tisserand says. 'There are dozens of essential oil sellers, and probably 95% will offer rosemary.' In this case, it's better to buy it online than in stores, he says, as the oil will be fresher. Google rosemary oil and look for specialty companies, not conglomerate sellers like Amazon.
What Should I Look for in Rosemary Oil?
Here are some things you may want to consider when buying rosemary oil:
Choose one with the fewest ingredients. Weed out brands that seem to have a lot of fillers, waters, and other cheap add-ins. Make sure the ingredients are clearly listed on the label.
A scent you enjoy. An essential oil can have desirable properties, but if you don't like how it smells, you probably won't use it.
Make sure it's been properly tested. Gas chromatography/mass spectrometry (GC/ MS) testing should be done by batch to ensure purity and highest quality.
Check certifications. Look for products that are certified USDA organic. Other good certification guidelines include non-GMO, Leaping Bunny Cruelty Free, and PETA's Vegan & Cruelty Free.
Takeaways
Rosemary is more than a fragrant, flavorful herb. As an essential oil, it has properties that can help ease pain, help you focus and remember things better, and boost your mood.
It's also been proven to improve hair growth at least as well as commonly known over-the-counter products.
Rosemary oil should be diluted in oil or gel before using it on your skin.
While you can enjoy eating rosemary as an herb, doctors advise against taking essential oils internally.
Rosemary Oil FAQs
Who shouldn't use rosemary oil?
People who have Crohn's disease, ulcerative colitis, ulcers, or high blood pressure shouldn't use rosemary oil. Also, women who are pregnant or breastfeeding should avoid it.
Should you put rosemary oil on your skin?
Yes, but make sure it's diluted in the right proportion. Use a chart such as this one by the National Association for Holistic Aromatherapy.
What does smelling rosemary oil do for you?
Rosemary aromatherapy is well known for improving focus, boosting memory, and lifting your mood. It can make your blood pressure higher too, as it helps alertness, so people with high blood pressure should avoid it.