Rosemary - famous for it's memory enhancing properties, but did you know it is also a fantastic mosquito repellent? Click the image to read about the scientifically verified benefits of rosemary oil!

Rosemary Oil – Just the Facts 8


Rosemary - famous for it's memory enhancing properties, but did you know it is also a fantastic mosquito repellent? Click the image to read about the scientifically verified benefits of rosemary oil!In Shakespeare’s Hamlet, the character Ophelia declares: ‘There’s rosemary, that’s for remembrance. Pray you, love, remember.’ Throughout history, rosemary and rosemary oil have been used to enhance memory (Grecian scholars used to wear rosemary wreaths on their heads for exams!) Rosemary also has a bit of a reputation as a gastrointestinal healer, among other, more fantastic claims such as a hair re-growth serum and mosquito repellent. In this article, I’ll explore all the claims made about rosemary oil and compare them with scientific evidence, thus illuminating the REAL benefits of rosemary oil. 

As a young scientist, I know how hard sifting through and understanding academic articles can be, so I endeavor to remove (or explain) the jargon for you guys, making this research accessible to everyone. Because this information shouldn’t be limited to people who know words like antiplasmid and ambulatory (or those who have a crazy amount of free time to google each word).

Interested in how to use rosemary oil? Download my free rosemary oil cheat sheet from my library of resources by clicking below! It’s full of super helpful recipes and tips for each of the (scientifically verified) uses. 

free-uses-and-recipe-sheet

Origin

Rosemary (or Rosmarinus officinalis) is native to the Mediterranean region of the world. It comes from the mint family of herbs, Lamiaceae, which also includes herbs such as basil, mint, sage, savory, marjoram, and others. 

The first documented medicinal use of rosemary was recorded in England, where Rychard Banckes suggested boiling rosemary and drinking the tea to expel “evils in the body.” It was used to cure a variety of ailments, ranging from aching joints to poor digestion. This concoction even reportedly cured Queen Elizabeth of Hungary of semi-paralysis. 

 

Claims about Rosemary Oil

  • Memory Enhancer
  • Hair Re-growth
  • Liver Detoxifier
  • Improves Gallbladder Function
  • Pain Reliever
  • Anxiety Relief
  • Immune Booster
  • Antimicrobial 
  • Dandruff Relief
  • Mosquito Repellent

Memory Enhancer

Research has shown that rosemary likely does have a significant, positive effect on proscriptive memory, which is the ability to remember things happening in the future, and also improves reaction time. [1] They found that a compound present in rosemary, 1,8-Cineole, is absorbed into the bloodstream when rosemary oil is inhaled, and they propose that due to its molecular structure it is able to cross the blood-brain barrier and have an effect on neuronal function. 

Bottom line: Inhaling rosemary oil will probably improve your ability to recall things such as to-do lists and events happening in the future.

Related: Top 3 Essential Oils for Memory

Hair Re-Growth

There seems to be significant evidence that rosemary oil can promote hair re-growth at a level similar to minoxidil (brand name Rogaine) in people with androgenetic alopecia (which is a fancy way of saying male/female pattern baldness). [2] In fact, these researchers found that in addition to showing a statistically similar level of hair growth, rosemary oil had less side effects, specifically less scalp itching. 

This expands on an earlier finding in 1998 that showed the effectiveness of a blend of essential oils (thyme, rosemary, lavender, and cedarwood) on reduction of alopecia aerate (patchy hair loss). [3]

Bottom line: Rosemary oil is likely an effective alternative to store-bought hair re-growth products.

Liver Detoxifier

Carnosic acid, which can be extracted from rosemary oil, has recently (2016) been shown to decrease serum aminotransferase (commonly measured indicator of liver damage), triglyceride (fat in the blood), and total cholesterol levels in rats with induced alcohol liver damage. [4] 

In that study, the carnosic acid was administered orally, but I do not recommend consuming essential oils in any sort of large dose (more than a couple drops) without consulting a physician. These oils are drugs by definition, so please exercise caution. It is far too easy to overdose. 

It is also important to note that the researchers were using nearly pure carnosic acid, whereas this comprises only 4-10% of rosemary leaves by weight (depending on the variety). [5]

Bottom line: Rosemary oil can contribute to reduction of liver damage, but cannot be relied upon to completely reverse liver damage.

Pain Relief

Rosemary oil has been found to reduce induced pain (using acetic acid) in rodents, although when compared to the active component of Aspirin, requires a much higher dose (12mg/kg of Aspirin vs 108mg/kg of rosemary oil). [6] 

Additionally, components of rosemary oil have been compared to Tramadol (brand name Ultram, an opioid pain medication). All three components (rosmanol, cirsimaritin and salvigenin) were found to have comparable analgesic (anti-pain) effects in mice that were comparable to Tramadol at similar doses. [7]

Bottom line: There is good evidence that rosemary oil can reduce different types of pain, although not always at the same effective dose as brand name pain relief medications. 

Anxiety Relief

The same study as above [7] also found that the same three components of rosemary oil had anti-anxiety effects in mice. When compared to Imipramine (brand name Tofranil), the rosemary oil components produced a comparable anti-anxiety effect. 

Another study in 2005 [8] found that one of the three components mentioned above (rosmarinic acid) produced anti-anxiety effects in mice, and was likely the basis of the choice of component in the later study. 

For those who prefer human models, there is a (questionable) study that claims they saw reduction in test anxiety in nursing graduate students who wore satchets of rosemary. [9]

Bottom line: Rosemary seems to be effective against anxiety at levels comparable to prescription anti-anxiety medications.

Immune Booster

I haven’t been able to find any research to support this claim (feel free to point out any you know of). If you’re looking for an immune-boosting oil, check out Frankincense oil. And during cold and flu season, look for antibacterial oils to prevent infection in the first place. 

Antimicrobial

In 2011, rosemary oil was tested for it’s antimicrobial activity against Gram positive (S. epidermidisS. aureus and B. subtilis), Gram negative (P. vulgarisP. aeruginosa and E. coli) bacteria and fungi (C. albicansA. niger). In all cases, the minimum inhibitory concentration of rosemary oil was found to be between 0.1% and 0.3% dilution. [10]

Of course, these days microbes are becoming increasingly drug-resistant, so in 2013, researchers tested rosemary oil against multi-drug resistant strains of E.coli. They found that rosemary oil effectively inhibited growth at a concentration of around 19uL/mL, which is about 1.9%. [11] While this is higher than the concentration needed to inhibit non-resistant E.coli, it’s still a very reasonable dilution of the oil for everyday use. 

Related: Grab a Free Dilution Guide from my resource library!

Bottom line: Rosemary oil is an impressive antimicrobial agent, suitable for use against a wide variety of bacteria. 

Dandruff Relief

The cause of dandruff is still undecided, although it is commonly believed to be due to a bacteria or fungus inhabiting the scalp. As mentioned above, rosemary oil is a great antimicrobial agent, which may be why it is recommended as a remedy for dandruff. However, no direct research has been done (that I can find, feel free to point some out) to test the effectiveness of rosemary oil on dandruff. 

Gallbladder Function

While rosemary is often recommended as a treatment for gallstones and other gallbladder problems, there is no research (that I can find, feel free to point some out) that has tested these claims directly. 

Mosquito Repellent

In a very recent journal article (Jan 2016), researchers tested a collection of essential oils as mosquito repellents using a newly developed method they call “Singing in the Tube.” Using this audiovisual assay, they determined that rosemary was not only the best mosquito repellent of all oils tested, but had mosquito repellent abilities superior to DEET. [12]

Bottom line: Rosemary oil probably makes a pretty good choice for mosquito repellent, but has not been tested against other insects. 

So to recap, the verified claims about rosemary oil are:

  • Memory Enhancer
  • Hair Re-growth
  • Liver Detoxifier
  • Pain Reliever
  • Anxiety Relief
  • Antimicrobial 
  • Mosquito Repellent

What is your experience with rosemary oil? Any favorite ways to use it? I’d love to hear! Let’s chat in the comments below!

If you loved this article, you can read more Just the Facts posts here.

Interested in how to use rosemary oil? Download my free rosemary oil cheat sheet from my library of resources by clicking below! It’s full of super helpful recipes and tips for each of the (scientifically verified) uses. 

free-uses-and-recipe-sheet


About Rachel

Rachel is a blogger and Bioengineering masters student who lives in Clemson, SC (go tigers!). After studying conventional pharmaceuticals and how they target specific ailments, she applied that knowledge to figuring out how essential oils can work to treat the same ailments, and ended up creating the blog The Essential Girl. When she’s not blogging or sciencing the shit out of something in the lab, she likes to drink tea, nom on popcorn, and binge Netflix.

  • Avonelle

    Great post, Rachel! Thanks so much for the information. I had no idea rosemary oil had so many uses, or could help in so many ways! I will have to remember to try it as a mosquito repellent. Living in hot Alabama, we have a lot of mosquitoes, and they can be quite annoying.

    Keep up the good work!

    • Avonelle,
      Glad you found it useful! Let me know how well the rosemary works against your mosquitos!

  • Valerie Vanderheiden-Rath

    Great post! I’ve been really getting into Essential Oils lately and Rosemary is one of my new favorites.

  • Sandy Hugill

    I love your “Just the Facts” posts, especially the newer format with the Bottom Line for each claim. Thanks for sorting through the scientific literature and distilling the facts for us. Please bring more!

    • I’m so glad you’re enjoying them! Thanks for taking the time to let me know! 🙂

  • Bhardwaj

    how to apply rosemary essential oil for hair. Is jojoba oil more suitable carrier oil or almond oil ?

    • The carrier oil doesn’t matter nearly as much as the essential oil for the purpose. You could get away with using a cheaper oil like coconut and still see the same effect from the rosemary oil, because there generally isn’t a reaction between the carrier oil and the essential oil.

      • Bhardwaj

        Thank you so much .