July 30, 2025
“Washing with Dr. Bronner’s Peppermint soap is like getting hugged by a snowman.” This was one of my Uncle Ralph’s frequent ways to introduce people to the Peppermint Magic Soap. I’m not sure if he knew it, but research backs him up on this. Maybe not the animated snowman part, but the part about the cooling effect of mint.
When it comes to essential oils, there’s nothing like peppermint. An energizing whoosh of crisp arctic air, leaving your body and senses clean and renewed.
Mythological roots
I love a good origin story, and mint’s got one. According to myth, Minthe was a mistress of Hades, the god of the underworld. As these things often go, Hades also had a wife, and a fairly powerful one at that: the goddess Persephone.
Persephone didn’t take too kindly to her competition and had the means to do something about it. She turned her rival into a plant. Hades, though sad, couldn’t undo the spell, but he did bestow on his now-planted squeeze a beautifully sweet scent. Wasn’t that nice? And that’s how mint came to be.
The scientific side of mint
Botanically speaking, mint is the genus mentha, under the family Lamiaceae. The Lamiaceae family includes most of the aromatic or culinary herbs you could think of such as lavender, basil, sage, thyme, and oregano. Often, the whole Lamiaceae family is called “The Mint Family,” which is a little misleading when there’s also a genus within it called mentha, but it points to the fact that most aromatic plants you can think of are botanically related to each other. (One fun fact about many plants in the Lamiaceae family is that they have square stems. Check it out for yourself!)
There are hundreds of types of mint in the genus mentha, some of which don’t even sound like a mint, such as Pennyroyal. But even within the mintiest of the mints, there are three species that are most familiar to me because they are the three used in Dr. Bronner’s products: Mentha x piperita, Mentha arvensis, and Mentha spicata.
Generally, piperita is what we refer to as peppermint and spicata is spearmint, but within these species, there are numerous cultivars. I’m inclined to say that if you can think of an evocative adjective, there’s probably a type of mint called that: lavender mint, chocolate mint, grapefruit mint, basil mint, Moroccan mint, curly mint, banana mint, Japanese mint, ginger mint. Whew! My takeaway? Never send someone else to pick up a “pot of mint” from the nursery for you. You’d never know what you’ll get.
Plus, the term “peppermint” gets used interchangeably for a lot of different types of mint, not just the Mentha x piperita varieties.
Growing and propagating mint
Let’s say you go to a friend’s house and they have a mint plant you just love. Instead of scouring nurseries for that exact variety (good luck!), clip off an 8-inch stem from your friend’s plant, plunk it in a glass of water, and let it grow roots. When those roots look robust, plant it in soil, and you’ll have your very own mint plant. It’s that easy.
If you’ve ever thought you have a black thumb, grow mint. Mint can make a gardener out of anyone. However, beware. When mint is happy (and so long as there’s some water, mint happily adapts to many environments), it grows and spreads very rapidly, which gets it called “invasive” on its report card. This means if you don’t want your whole yard covered in mint, it’s best to confine it to a pot.
Dr. Bronner’s history with peppermint
Peppermint was unequivocally my grandfather’s favorite scent. (My grandfather, as in Emanuel Bronner, whom you may know as Dr. Bronner.) It was the original scent of his now-iconic Castile Magic Soap, which he first made as a soap for washing his children, their laundry, and their diapers.
Even once he began selling the soap, he stuck solely with the Peppermint for over 20 years before releasing another scent (which was Almond – I talk about the history of the scents in my book Soap & Soul). I never saw him personally use any soap scent other than the Peppermint, and he swore by the invigorating effects of a rub-down with Peppermint soap on a hot washcloth, “always rubbing towards the heart.”
Before I had any understanding of plants or mints or essential oils, I always knew there was something special about the Dr. Bronner’s Peppermint. Other peppermint products I’d smelled, from candies to candles to lotions, never had that wake-you-up-and-cool-you-down skin tingling refreshment of my grandfather’s castile soap. What did that? Turns out he harnessed a blend of two types of mint essential oils: Mentha arvensis and Mentha piperita. The piperita brings the sweetness and arvensis packs the spice.
Eventually, blending mints became an art form in the family and the company. Throughout the Dr. Bronner’s Peppermint product line, you’ll find different nuances to the mints. For example, as a contrast to the spiciness of the Peppermint Castile Magic Soap, the Peppermint Organic Sugar Soap blends Mentha piperita and Mentha spicata, with no arvensis, resulting in a mellower, sweeter scent. Standing opposite on the mint potency scale, you’ll find the Arnica-Menthol Organic Magic Balm, containing not only Mentha piperita, but also menthol crystals, which are distilled and concentrated from Mentha arvensis, giving this balm the mightiest mint in the house.
As it has always been, Peppermint is the most popular scent across Dr. Bronner’s product line, appearing not only in Castile Magic Soap, Sugar Soap, and Magic Balm, but also in Organic Shave Soap, Organic Lip Balm, Organic Lotion, Organic Hair Crème, All-One Toothpaste, and Organic Hand Sanitizer. This scent alone accounts for over 25% of all product sales.
To keep up with this usage, Dr. Bronner’s purchases over 200,000 pounds of pure, undiluted mint oils a year, making it the fourth largest ingredient by volume the company uses. And not just any mint oils will do. The company’s Cosmic Principles emphasize being fair to suppliers (#4) and treating the earth like home (#5), which means pursuing initially organic, then fair trade, and now regenerative organic sources of these oils.
Eventually there were no sources with these standards large enough to provide Dr. Bronner’s with this amount of mint oil anywhere in the world. This led the company to spearhead the establishment of a new mint oil mill in Uttar Pradesh, India, to work with family farmers and supply the company’s oil needs. The suspenseful story of this mill, called Pavitramenthe, is fully told in the book Honor Thy Label, written by my colleague, Dr. Bronner’s Vice President of Special Ops, Gero Leson. In short, Pavitramenthe dodged a lot of obstacles and now sends over 6 shipping containers a year our way with Regenerative Certified Organic mint oils.
Extracting organic peppermint oil via steam distillation
Unlike many other essential oils, mint oil is not extracted from just the flowers or the leaves, but from the entire plant. While there are a variety of extraction techniques, steam distillation using only vaporized water is what produces organic mint essential oils. The plants are packed into a closed vessel. Steam is forced through the vessel from the bottom, working its way up through the plants, grabbing the volatile oils (which essential oils are), and then out through coils in the top of the vessel. Cooling coils then capture the water/oil vapor, cool and condense the vapor back into liquid, and then let the two substances naturally separate due to differences in density. Oil, with its lighter density, will rise to the top, where it can be siphoned off.
Menthol is what makes mint oil so very minty
The active ingredient in mint oil, by which we readily recognize it, is the compound menthol. Menthol is a cyclic monoterpene alcohol. It’s that pungent, vaporific, sinus-tickling compound that smells so very active and compelling, whether we apply it to our chests, our muscles, our feet, or wherever else seems in need of therapeutic attention.
Menthol is present in different amounts across varieties of mints. I had assumed that Menthe piperita, with its peppery name, has the highest level of menthol, which I would describe as a particularly peppery compound. However, Menthe arvensis gets the menthol trophy with twice the concentration of naturally occurring menthol, constituting a whopping 65+% of its oil.
The impact mint has on skin
People have turned to peppermint for millennia to remedy a range of maladies and discomforts, from headaches to indigestion to bug bites to aching feet. While homeopathy and folk wisdom have a great deal to teach us, researchers have been wanting to pin down exactly the what, why, and how of mint’s impact on our bodies. Are such things measurable? Indeed some are.
While there is still much to learn about the precise mechanism of mint in and on our bodies, some of its effects on skin are well understood and documented. The focus for both of these next points is the presence of menthol.
Menthol creates a sensation of coolness on skin
While there are many theories and hypotheses about what all menthol-laden peppermint can do, there is one ability that stands out and is super well-documented. You’ve probably noticed it yourself. Menthol can change our bodies’ perception of temperature without actually changing the temperature. How cool is that?! This bit of epidermal trickery is one of menthol’s prized superpowers and makes peppermint the best antidote to summer heat.
Though the cooling effect of peppermint has been long known, it wasn’t until the early 2000’s that scientists were able to isolate an interaction between menthol and TRPM8 receptors in our skin, which are the nerves that sense cold. When the menthol stimulates the TRPM8 receptors, our brains get a message of “Cold!” This makes us feel cooler even though there has been no change in temperature.
Perhaps you may say, “But it’s not really doing anything. It’s all in our head!” Removing even the perception of discomfort (of excessive heat, in this case) can improve quality of life, although care should be taken to avoid heat related illnesses. Menthol does not protect against those and can blunt the awareness of heat accumulation. In the inimitable words of Albus Dumbledore, “Of course it is happening inside your head, Harry, but why on earth should that mean that it is not real?”
Menthol affects blood flow to the skin
A second well-doumented impact of menthol on the skin has to do with its action on our veins and blood flow. Researchers have observed that skin exposed to menthol experiences vasodilation, resulting in increased blood flow, while at the same time, skin elsewhere on the body not exposed to menthol experiences vasoconstriction, leading to decreased blood flow. However, while researchers can see that this happens, they don’t know precisely why. There are a number of hypotheses to explain this, such as the body’s conservation of heat or blood flow balance, but verdict is still out. It is generally agreed that increasing blood flow allows for greater delivery of nutrients and oxygen to the skin, while carrying away waste.
Is mint oil right for you and your skin?
Every essential oil is full of individual impact and personality, and there is no one-size-fits-all approach to these compounds. With their vibrancy and energy, this is especially true for peppermint and other mint oils. They are an awesome ally for some people, but not for everyone.
To start with, mint oils always need to be diluted and should never be applied directly to the skin. It can irritate the skin. If it isn’t being used in a formulation such as for lotion or soap, then mix a few drops of your favorite mint oil (so many to choose from!) into a carrier oil like coconut or olive oil.
As you ponder the impacts to skin I’ve just mentioned, including the menthol’s cooling effect and increasing blood flow, there are a few questions to answer before you decide if peppermint essential oil and skin care products containing it are right for your skin tendencies and personal preferences.
Do you want to feel cooler?
The cooling effect of peppermint is prized by some, but not by all. Folks who live in a humid climate or tend to feel habitually warm, embrace the cooling mint, but for folks on the other side who are prone to feeling cold, this might not be a desired or pleasing effect. That snowman hug that my Uncle Ralph described might be more shivery than exhilarating.
Also, with infants and little ones who might not understand why their skin suddenly feels tingly, products with peppermint oil can be too exciting. When my kids were infants, I chose not to use peppermint soap in their bathing because I thought all that tingling might startle them. So until they were old enough to talk about this sensation, I opted for one of the other Magic Soap scents, usually the Almond or Lavender.
Furthermore, some TRPM8 receptors may really ratchet into high gear once they’re activated by menthol. Instead of sending a message of “pleasantly cool” to the brain, they send a message of freezing or burning, and the body leaps into damage-control mode. This may happen on particularly sensitive skin, such as the face, or even the whole body for certain individuals. Skip the peppermint in these situations.
Do you want to increase blood flow to the skin?
A second question to ask yourself in your contemplation of mint is whether you want more blood flow to your skin. Increasing blood flow to the skin can allow the skin to repair and rejuvenate faster, and can improve skin color. However, individuals who are prone to unwanted redness may not want to promote an increase in vasodilation. This may be a question to discuss with your medical advisor, who may recommend opting for essential oils that have a milder relationship with the skin.
Wrapping it all up
Mint is a scent that is impossible to ignore. It surrounds us in many forms from the edible to the restorative to the decorative. It is instantly recognizable and readily evokes memories and associations.
But it is even more than that. Peppermint and its minty cousins have an observable and measurable impact on our skin. Indeed, our skin really does tingle in its presence.
Further reading:
- Making Ethical Palm Oil a Reality
- My Favorites – Get to know the 8 Castile Soap Scents
- Dilutions Cheat Sheet for Dr. Bronner’s Liquid Castile Soap
Peppermint and Eucalyptus are not recommended for children under 3 years of age as these scents may be overwhelming for them.