Curious controversy of peppermint oil and hair growth.
While writing this article we were taken on a ride, ride made of peppermint oil and cooling sensation of the controversy we had found in the scientific research. But in the style of our blog, let’s first look at the science and chemical structure of peppermint oil and understand what it is comprised of.
What is made of?
Peppermint oil is made of peppermint (Mentha × piperita), a hybrid mint, a cross between watermint and spearmint. Indigenous to Europe and the Middle East, the plant is now widely spread and cultivated in many regions of the world. The main constituents are menthol and menthone.
Menthone is an organic compound commonly found in plants and insects to deter predators, including herbivore animals with minty flavour. Menthone is a type of turpentine, same compound that you find in painting supplies, that has a characteristic, pungent smell. Menthone is what gives peppermint its fresh and invigorating aroma.
Menthol is a crystalline organic compound with a well known and researched local anaesthetic and counterirritant qualities. Menthol is commonly added to anaesthetic gels applied topically to relieve muscle tension and pain. It is also a common ingredient in skin-soothing balms and ointments.
Effectively, menthol in toothpaste tingles your mouth and gums, while menthone is what makes it smell fresh.
Some people believe because of menthol’s cooling sensations and anaesthetic properties it induces vasoconstriction effect, i.e. shrinking of blood vessels. But an overwhelming amount of scientific research repeatedly shows vasodilatory effect, i.e. expansion of blood vessels. Menthol applied topically is the component which increases blood flow when applied to skin, but it also numbs and cools it, which is what leads some people to think of it as a vasoconstrictor. (Source and Source). (We went a little bit mad trying to understand this, and only reading a number of those papers we understood this peculiar “controversy”.)
Expansion of blood vessels
Vasodilation, or expansion of blood vessels has a direct effect on blood flow. And increased blood flow has been proven to increase activity in the hair follicles and therefore directly impact by increasing hair growth (Source). Which is one of the reasons why in a recent notable study, peppermint oil outperformed minoxidil, a well known hair growth medication, in helping hair growth. The graph below shows the difference in performance between peppermint oil, minoxidil, jojoba oil and a saline solution (placebo). (Source)
A perfect companion
These qualities of peppermint oil may well make it the perfect travelling companion on the go, since blood vessel expanding and anaesthetic properties is known to aid various other health conditions, including providing relief for headache, nausea, as well as relieving itching and burning sensation from sunburns and mosquito bites. Peppermint oil and menthol are commonly added to anti-dandruff shampoos and conditioners due to its soothing properties. Its aroma has been known for centuries for its calming effect as well – which can help in the times of stress and overwhelm. Just a few drops on wrists and forehead can help you ground and center yourself in a stressful situation.
We could not ignore these outstanding qualities of peppermint oil, which is why it became one of the ingredients to The Hair Fuel, our signature, all natural hair growth mask. Coupled with refreshing smell as well as its blood flow improving a.k.a. hair growing properties – made it an invaluable contributor and a final “cherry-on-top” touch to the your hair growing journey.