There are many causes of hair loss and, as such, many viable treatment options.
Some options have better results than others, and some even have less side effects than the more conventional treatments – including Propecia and Rogaine.
One such option for treatment? Peppermint Essential Oil (PEO).
This article will discuss the leading cause of hair loss – Androgenetic Alopecia (AGA), and how peppermint oil can be used to treat and, perhaps even reverse, its effects.
It will also introduce the scientific proof behind these claims, and how you can use it effectively in your daily hair care routine.
What Is Peppermint Oil?
A cross between spearmint and watermint, peppermint is a hybrid plant within the Lamiaceae family (1). It’s used often in food (in flavoring tea, gum, mints, and ice cream), but it has also begun to find its place in the cosmetics and health industry.
Can It Treat Hair Loss?
To understand the ways that peppermint oil may be useful in treating thinning and balding, it’s important to know why hair loss occurs.
While there are many causes of balding – from illness and injury to hormonal changes to stress – the main cause is Androgenetic Alopecia (AGA) (2). This occurs in both men and women, and it’s also known as pattern hair loss.
But what’s the cause?
The exact cause has yet to be pinpointed by scientists. Though, there are a few factors which are believed to play a role. These include:
- Androgen (DHT) sensitivity
But the last one, in particular, is of interest to researchers.
Dihydrotestosterone (DHT) is an androgen hormone that’s a by-product of the interaction between testosterone (the male sex hormone) and 5-alpha-reductase (5AR), an enzyme (3).
It’s produced mainly in the testes, though free testosterone (fT) which travels throughout the body can also be converted to DHT.
Where does fT travel?
The hair follicle is one such place where fT dwells and is converted to DHT, which is of importance to hair loss sufferers.
In many people, this conversion causes no harm. However, men and women with AGA will experience a process called follicle miniaturization (2).
Of course, the process of hair loss isn’t quite so straightforward. There are many other factors which contribute to hair loss, including poor blood flow and lack of oxygen, both of which are side effects of miniaturization (4, 5).
So, what role can peppermint oil play?
- Stimulate the anagen growth phase
- Improve blood supply
- Treat antifungal and antibacterial infections
- Prevent and treat inflammation
When combined, these abilities make peppermint oil a powerful option.
The Scientific Proof
Let’s look closely at a few studies which seem to support PEO’s use in treating hair fall.
The most promising study, which showed the direct results of PEO use on balding, was performed in 2014 on mice (6).
The mice – 20 in total – were shaved on the dorsal area and then split into four groups. The groups received different topical treatments, which were:
- Saline (SA)
- Jojoba Oil (JO)
- 3% minoxidil (MXD)
- 3% Peppermint Essential Oil (PEO)
The treatment was applied to the dorsal area six days per week for four weeks.
Hair growth was measured by two methods. The first were photographs, which were taken at regular intervals throughout the four-week study. They were each categorized as follows:
- 0: no hair growth
- 1: less than 20% growth
- 2: 20% to less than 40% growth
- 3: 40% to less than 60% growth
- 4: 60% to less than 80% growth
- 5: 80% to 100% growth.
The second method involved skin biopsies, which were taken at the end of the study.
The groups that received either saline or jojoba saw minimal hair growth throughout the study. On the other hand, both the minoxidil and the PEO groups saw significant hair growth from week two.
This growth continued for both groups, even at the end of the study, which indicates a prolonged anagen phase of hair growth.
But what about the biopsy results?
First, the biopsies show elongation of the hair follicles and shaft in the minoxidil and PEO groups.
Second, the PEO group had seven times and three times more hair follicles than the saline and jojoba groups, respectively.
And, researchers even found that blood circulation to the scalp was increased via monitoring of Alkaline Phosphatase (AP) activity.
In conclusion, researchers determined that “PEO effectively stimulated hair growth in an animal model via several mechanisms and thus could be used as a therapeutic or preventive alternative medicine for hair loss in humans.”
While the above study highlighted the direct effects of PEO on hair growth, there are other studies which indicate PEO’s many other beneficial properties.
One such study was performed in 1996, and it indicated PEO as an effective antibacterial and antifungal agent (8). The study compared the effects of 10 different essential oils against 22 bacterial and 12 fungal strains.
Peppermint oil performed well, inhibiting all 22 of the bacterial strains and 11 out of twelve of the fungal strains.
What do these results mean for hair loss sufferers?
AGA is the most common cause of thinning and balding in men (and one of the leading causes of hair fall in women). But it’s not the only cause.
Bacterial and fungal overgrowth, which can occur on the scalp, may also contribute to balding (10).
Infections, like tinea capitis and dandruff, can cause inflammation, itching, and general irritation. The act of scratching can dislodge hairs and the infections themselves can disrupt the hair growth cycle.
By treating infections on the scalp, you make it possible to improve the overall environment. This is beneficial for hair follicle health and for hair growth.
Bacterial and fungal infections aren’t the only conditions that can cause inflammation of the scalp.
Parasites can also contribute. And while parasites may not be a common cause of balding, this next study does shed some light on how peppermint oil may be helpful in reducing inflammation.
The study, performed in 2016, focused on two components of peppermint oil – menthol and methone (9).
The mice used in the study were split into five groups. They were:
- Negative control, which was not infected with the parasite
- Positive control, which was infected with the parasite, but not treated
- Mentha 15, which were treated for 15 consecutive days with 50mg/day
- Mentha 60, which were treated for 60 consecutive days with 50mg/day
- Praziquantel, a drug commonly used in the treatment of the infection
The only group not infected with the parasite was the negative control.
NOTE: The menthol in this study was derived from a pharmaceutical source – Mentaliv, which is commonly used to treat Irritable Bowel Syndrome (IBS). Its components include up to 55% menthol and up to 32% menthone.
To determine the effects of the parasitic infection and the efficacy of the treatments used, researchers monitored cytokine levels (11). These are pro-inflammatory proteins and, as such, will be present in larger numbers when infection is present.
After 61 days of infection, the cytokine levels were taken.
The Mentha 60 experimental group exhibited the best results when compared with the positive control. More specifically, IL-4 levels were reduced by 53.5%, and IL-10 levels were reduced by 62%.
These reductions were even better than those in the Praziquantel treatment group.
But does this mean that peppermint oil, of which menthol and menthone are major components, can also help to fight infection and accompanying symptoms (12)?
While further studies need to be performed particularly in human subjects, it does seem to be a promising treatment option for parasitic infections, and even inflammation.
United States (2016)
Menthol, the same ingredient mentioned in the previous study, provides another benefit to men and women with thinning and balding – it increases circulation to the scalp (7).
What exactly does this mean, and how is it helpful?
As follicle miniaturization sets in, the surrounding area becomes inflamed and irritated (2). This inflammation affects every part of the hair follicle, including the bulb.
The bulb is located at the base of the follicle. It’s connected to the scalp’s blood vessels which, in turn, makes it the source of all nutrients and oxygen within the hair follicle.
When miniaturization occurs, the connection between the bulb and the blood vessels is slowly strangled. It can eventually become cut off entirely, which will result in irreversible balding.
So, by increasing blood flow to the scalp the chances of nutrient and oxygen delivery are improved. This is critical if hair is to regrow and thrive in its environment.
In fact, oxygen plays a more important role in hair loss (and growth) than was once thought. Here’s how.
As mentioned above, DHT is produced from the interaction between testosterone and 5AR. This occurs in various parts of the body, but we’ll focus on the scalp and hair follicles specifically.
When this interaction occurs, more than just testosterone and 5AR are needed. Oxygen is also a critical component of the process (13).
However, the interaction doesn’t need much oxygen to be completed. So, even low-oxygen environments (such as the scalps of people with AGA) can still produce DHT.
By increasing oxygen levels to the scalp, you reduce the levels of DHT being produced. Here’s why.
This means that a high-oxygen environment will produce both DHT and estradiol. And why is that good? Because this estrogen hormone has actually been shown to induce hair growth (16).
So, how can peppermint oil help?
In 2016, researchers from the United States showed that menthol increases cutaneous blood flow when applied topically (7). This was measured by Cutaneous Vascular Conductance (CVC), and the higher the concentration the more blood flow to the area.
As such, it would make sense that menthol-containing extracts (such as peppermint oil) would induce blood flow and improve the environment for hair.
Side Effects and Contraindications of Peppermint Oil Supplementation
As with any ingredient, there are certain risk factors which must be considered before using.
Peppermint oil should be avoided by women who are pregnant or breastfeeding, as little evidence is available on its use in such populations (17).
Use on children isn’t recommended, and use near the eyes, mouth, or nose should be avoided.
While rare, adverse effects can occur when PEO is applied to the skin. These are typically minor, and they include (18):
- Flushing of the surrounding skin
- Coughing and/or wheezing
- Difficulty breathing
If you suspect an allergic reaction, seek emergency medical attention. In severe cases, the reaction can progress and result in anaphylaxis which, if left untreated, is fatal.
How to Use Peppermint Oil
There are many ways you can benefit from the supplementation of peppermint oil.
Dilute Your Essential Oils
First, a note: As an essential oil, PEO must be diluted before it’s applied to the skin. PEO should NOT be taken orally unless it’s designated for oral consumption, and it should be heavily diluted or taken in capsule form.
When using essential oils, it’s important to combine them with a carrier oil.
These help to deliver the essential oils more efficiently, and they also prevent burns/irritations that can be caused by undiluted essential oils.
As a general rule of thumb, the dilution rate should be 5mL of carrier oil for every drop of essential oil.
Apply to the Scalp
The most direct method of use is to apply peppermint oil to the scalp with the use of a carrier oil. You can take your pick from the many options, including:
- Coconut oil
- Magnesium oil
- Almond oil
- Sunflower oil
- Jojoba oil
For best results, apply your mixture of oils to the scalp each evening. You can boost results by massaging the scalp during your session.
How to Massage the Scalp
Place your thumbs and index fingers on either side of your head above the ears. Use a gentle, circular motion to massage the oil into the scalp.
You’ll begin at the sides, then move to the crown, temples, and finally to the base of the skull.
This will improve circulation to the scalp and soften the tissues (21). It will also ensure proper application of the oils.
Use a Dermastamp
While massage has beneficial effects on the scalp, there is another way to increase blood flow and even stimulate the production of new cells – microneedling (22).
Microneedling is a therapeutic technique that uses tiny needles to wound the skin (23). As the wounds heal, a three-step process takes place that stimulates collagen production and new cells:
- Maturation (Remodeling)
And while the technique may seem counterintuitive, there are studies that show its use is effective for hair growth. One study even showed it to improve the efficacy of minoxidil (24).
There are two tools that are popularly used for microneedling – the dermaroller and the dermastamp. Both will provide similar results, though the stamp can be easier to target areas of hair loss and to manipulate on the scalp.
The increase in blood circulation to the scalp will also aid in delivering any topical applications, such as PEO, more effectively.
IMPORTANT! Be sure to wait 12 hours following the microneedling session before applying the oil mixture. Otherwise, there will be discomfort such as stinging/burning.
Alternatives to Peppermint Oil
Whether you’re just looking for another option or an additional oil to add to your regimen, here are some essential oils you can use in your hair care routine.
Belonging to the same family of flowering plants as peppermint, rosemary is a fragrant plant with needle-like leaves often used in cooking and white, pink, purple, or blue flowers.
Aside from its beautiful look and fresh scent, rosemary oil has numerous health benefits and properties. Namely, it acts as an analgesic, antimicrobial, anti-inflammatory, and antioxidant (25, 26, 27).
Importantly, there are actually quite a few studies to back its use for hair loss.
The first includes rosemary oil in a blend of other oils (including lavender, cedarwood, and jojoba) (28). The results showed the blend did promote hair growth in patients with Alopecia Areata.
And while the results are promising, they still left many questions to be answered.
One such question was whether rosemary oil played a role in hair loss and, if so, how much?
A 2013 study performed on mice helped to answer these exact questions (29).
The mice experienced hair growth interruption induced by testosterone treatment and were then treated with a daily application of rosemary leaf extract.
The results showed that not only did rosemary induce hair growth, but it did so by inhibiting 5-alpha-reductase (the enzyme responsible for testosterone’s conversion into DHT).
The oil was even compared to minoxidil 2% in the treatment of AGA in 2015 (30).
This study included 100 patients who were split into two groups, of which one received daily application of rosemary and the other received daily application of minoxidil 2%.
The results showed that both rosemary oil and minoxidil 2% promoted hair growth in AGA patients at similar rates.
Tea Tree Oil
Tea tree oil is another mint-scented leaf that has been used medicinally for many years. In particular, it’s been shown to have antimicrobial and antiseptic properties (31).
More recent research studies have also shown tea tree oil to be a potential antiandrogen, which means it may contribute to hair growth by inhibiting 5AR and blocking DHT (32).
While neither of the studies were shown to induce hair growth specifically, they do show promise.
The first was a case study performed in 2007, and its goal was to determine the cause of gynecomastia in three prepubescent boys (32). As the findings suggest, lavender and tea tree oil-containing products may be one such cause.
But what does that have to do with tea tree’s antiandrogenic effects?
Gynecomastia is a side effect seen in various prescriptions with proven antiandrogen effects, such as finasteride (33, 34). The reason for the antiadrogentic effect is that such drugs may contribute to testosterone’s conversion to estrogen as opposed to DHT.
This means the presence of gynecomastia indicates that tea tree may have antiandrogenic effects.
A 2013 study backs these claims, though a different androgen-related condition was used – hirsutism (35). This is excessive bodily or facial hair growth in women, and is often the sign of a hormonal imbalance such as Polycystic Ovary Syndrome (36).
The topical application of lavender and tea tree oils was shown to reduce hirsutism, which may indicate its role as an antiandrogenic substance.
Pumpkin Seed Oil
Pumpkin Seed Oil (PSO) is an oil extracted from the hull of the pumpkin seed. It has an array of health benefits, including mechanisms that are anti-inflammatory, anti-diabetic, and anti-carcinogenic (37, 38, 39).
An additional benefit which is only now beginning to come to light is its use as a hair growth promoter.
In 2014, researchers from South Korea recruited the help of 76 male patients diagnosed with mild to moderate AGA (40). Half of these men were given a supplement containing PSO, while the other half were given a placebo.
All men were instructed to take the pill daily, and this continued for 24 weeks.
NOTE: While PSO was a component of the supplement, it was not the only ingredient. Other ingredients include Octacosanol (from vegetable powder), Gamma linolenic acid (from evening primrose), and Lycopene (from tomato powder).
The results of the study, obtained using phototrichography, showed that the supplement group saw hair growth improvement over the placebo group. These included hair counts and diameters.
While the researchers cannot say definitively that PSO was the cause of these results, they do believe it played a role. In fact, they claimed “that PSO could improve AGA and that it should be considered a potential alternative treatment.”
Cedar Wood Oil
While there’s still much research that needs to be done on cedar wood’s health benefits, one study does seem to indicate its use in the treatment of AA (28).
The study in question was done in conjunction with other oils, including lavender, jojoba, and rosemary. These oils, when applied topically, aided in the treatment of AA.
Peppermint oil has many benefits, both for general health and hair. This has been proven with a variety of scientific studies.
Does this mean that peppermint oil alone can treat hair loss? No.
However, its use alongside other treatments – such as massage and microneedling – can aid in the regrowth process and improve your odds of hair loss reversal. Its many other health benefits, too, can prove beneficial whether you’re looking to regrow your hair or just create a healthier scalp environment.