What Is Rosemary Oil?

Medically reviewed by Arno Kroner, DAOM

Rosmarinus officinalis, commonly known as rosemary, belongs to the Labiatae or Lamiaceae family of plants, which also includes mint, lemon balm, salvia, marjoram, and oregano.

Rosemary is a potent source of plant compounds that offer a variety of health benefits. Fresh and dried rosemary is commonly used in the culinary world, but the plant, including its extracts and oils, have therapeutic uses, too.

Here’s everything you need to know about rosemary oil, including its potential health benefits, risks, and safety.

Benefits of Rosemary Oil

Rosemary contains a number of powerful substances, including carnosic acid, carnosol, and rosmarinic acid, which offer anti-inflammatory, antioxidant, and antimicrobial effects.

Fresh and dried rosemary is used in cooking as a flavoring agent and the plant is also used to make products such as rosemary extract, rosemary powder, and rosemary oil.

Rosemary oil differs from rosemary extract, as they contain different compounds in varying concentrations. Rosemary extract supplements can be taken orally, while rosemary oil is applied topically or inhaled as aromatherapy.

Applying rosemary oil to your skin and hair and inhaling it as aromatherapy may offer a few health benefits.

Related: Diffusing Essential Oils—How and Why It's Done

May Improve Hair Growth

Rosemary oil has been shown to stimulate hair growth in certain populations, including in people with androgenic alopecia, a type of hair loss also known as male pattern baldness in men and female pattern baldness in women.

Research suggests that rosemary oil may promote hair growth by enhancing blood flow to small blood vessels in the scalp, increasing the production of hormone-like lipids involved in hair follicle growth, and inhibiting inflammatory pathways involved in the progression of alopecia.

A 2015 study that included 100 people with androgenic alopecia found that when rosemary oil was applied to the scalp for six months, it was as effective as the hair loss treatment minoxidil (Rogaine) 2% ointment at increasing hair count over the treatment period compared with baseline hair counts.

Additionally, the group that used rosemary oil reported better treatment adherence as compared with the minoxidil group.

When mixed with other oils, such as thyme and lavender oil, rosemary oil may also help improve hair loss in those with alopecia areata, an autoimmune condition that causes hair loss.

What’s more, rosemary oil is being studied for its potential anti-dandruff effects. Researchers think that the terpenes and phenolic components found in rosemary oil may offer antimicrobial properties that help reduce the growth of certain yeasts involved in dandruff.

While these results are promising, research in this area is limited, and more high-quality studies are needed to investigate rosemary oil’s impact on hair growth and scalp health.

Related: The 12 Best Hair Growth Serums of 2023

May Improve Cognitive Function, Relieve Stress, and Boost Mood

When inhaled, rosemary oil may offer anti-stress, anti-anxiety, and mood-boosting effects, which may positively impact your mental well-being and benefit those with mood disorders.

Inhaling rosemary essential oil may help decrease stress and boost cognitive function by reducing blood levels of certain hormones involved in stress, such as corticosterone, while increasing levels of the feel-good neurotransmitter dopamine in the brain.

Inhaling rosemary oil allows certain compounds found in the oil to enter the bloodstream, where they can act directly on the brain, impacting mood, attention, and more.

Studies show that people treated with rosemary oil through aromatherapy reported feeling energized and “fresh.”

In a small 2012 study, 20 adults who were exposed to rosemary essential oil diffused in the air experienced improvements in performance on cognitive tasks, including tasks involving speed and accuracy.

A 2021 study of 80 nurses found that aromatherapy with rosemary essential oil helped decrease sleepiness and improve alertness compared to a control treatment.

Other studies have shown that rosemary oil aromatherapy may help ease symptoms of anxiety and depression in some people.

However, more research on the effects of rosemary oil aromatherapy on cognitive health is needed to fully understand how this natural treatment may help improve stress, increase focus, and benefit certain mood disorders.

Could Help Reduce Pain

Topical treatment with rosemary oil may help improve pain.

Molecules in rosemary essential oil are absorbed through the skin and impact pain pathways in several ways, including targeting pleasure memory sites in the brain and interacting with receptor sites for neurotransmitters involved in pain pathways.

A 2017 study that included 46 people with neuropathic pain related to diabetes found that treatment with an aromatherapy massage using a blend of oils, including rosemary, three times per week for four weeks led to significant reductions in scores of neuropathic pain and increased scores of quality of life compared to a control group.

Topical treatment with rosemary oil may also help improve musculoskeletal pain.

A 2017 study found that topical application of menthol and rosemary oils three times per day for three days alleviated the severity and frequency of recurrence of musculoskeletal pain in people with kidney failure undergoing hemodialysis.

How to Use Rosemary Oil

Rosemary oil is usually applied topically or used as aromatherapy.

To use rosemary oil as an aromatherapy treatment, you can diffuse rosemary essential oil in an essential oil diffuser or apply a few drops of rosemary oil to an eye mask before wearing it. Rosemary oil can be blended with other essential oils, such as lavender and thyme oils, to create a relaxing scent.

You can also simply inhale rosemary essential oil straight from the bottle.

When applying rosemary oil to your skin, it’s recommended to mix it with a carrier oil, such as jojoba oil, coconut oil, or sweet almond oil. Carrier oils help dilute essential oils when using them topically. Essential oils are highly concentrated, so mixing them with a carrier oil helps dilute them, making them safer for topical use.

Using carrier oils helps decrease the risk of adverse skin reactions, such as dermatitis, when using essential oils on the skin.

When using rosemary oil to promote hair growth, you can blend a few drops with your shampoo or conditioner or mix several drops of rosemary oil with a carrier oil and then massage it into your scalp.

Rosemary oil can be found in a number of hair products advertised to promote hair growth, from shampoos to scalp treatments. Keep in mind that while limited research suggests that rosemary oil may offer some benefits for hair growth, it’s unclear if it significantly impacts hair growth in everyone.

Dosage

Rosemary oil generally isn’t meant for oral use. Rosemary-based oral supplements usually contain rosemary powder or rosemary extract, which differ from rosemary oil.

Rosemary oil is concentrated, so only a few drops are needed to create a powerful aromatherapy or topical treatment.

Is Rosemary Oil Safe?

Even though it isn’t usually ingested, studies show that rosemary oil is safe to use in food and drink products in dilutions of up to 5%.

However, while small amounts of rosemary oil are sometimes used in the food industry as a natural preservative in products like meat and poultry, it’s best to avoid ingesting rosemary oil.

Rosemary oil is highly concentrated and may cause irritation and allergic reactions in some people. Plus, because it’s so concentrated, studies show that rosemary oil could have toxic effects, even when taken in small doses.

For this reason, rosemary oil is only recommended for topical use and in aromatherapy treatment. When using rosemary oil topically, it’s best to mix it with a carrier oil and always test a small patch of skin before applying rosemary oil to larger surfaces to see how your body reacts.

Potential Drug Interactions

Although rosemary oil isn’t known to interact with medications, consult your healthcare provider before applying rosemary oil to your skin, especially if you’re  currently using topical medications like ointments and creams

What to Look For

When shopping for rosemary oil, keep in mind that there are a number of rosemary-based products to choose from.

If you’d like to use rosemary oil for hair growth, consider purchasing a pre-made product made with rosemary oil or purchasing rosemary oil to blend with a carrier oil to create a scalp treatment.

Pre-made rosemary oil products meant for topical use, like scalp treatments and body oils, are usually created by blending rosemary essential oil with a carrier oil, like almond or coconut oil.

Rosemary essential oil is a more concentrated product that can be found online and in health food stores. It can be used to create your own skincare and as an aromatherapy treatment.

When shopping for rosemary oil products, always choose products from reputable companies that adhere to strict quality and safety standards.

Side Effects of Rosemary Oil

Rosemary oil could cause allergic reactions in some people. For example, applying rosemary oil to your skin could lead to skin irritation in sensitive individuals.

For this reason, it’s important to test rosemary oil products, such as rosemary oil scalp treatments and rosemary-based massage oils, on a small patch of skin before applying them to larger areas.

If you notice any skin or airway irritation after applying rosemary oil to your skin or using it as an aromatherapy treatment, stop using it and contact a medical provider for advice.

A Quick Review

Rosemary oil is an aromatic oil that can be diffused as an aromatherapy treatment or applied to the skin.

Some study findings suggest that rosemary oil treatments may promote hair growth, improve energy levels, and reduce pain. However, research investigating the therapeutic uses of rosemary oil is limited.

In addition to using rosemary oil as an aromatherapy and topical treatment, you can also reap the health benefits of this fragrant herb by using fresh or dried rosemary in recipes like soups, pastas, egg dishes, and salads.

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Read the original article on Health.