Peppermint oil is a great digestive aid, helping with IBS, indigestion, and cramps. People also apply it on the skin for headache and itching, and modern research uncovers some surprising additional perks. This post reveals the health benefits, uses, and side effects of peppermint oil.
What is Peppermint Oil?
Peppermint, also known as Mentha piperita, is a common herb. It is available in many forms – peppermint leaf, peppermint essential oil, peppermint leaf extract, or peppermint leaf water [1].
Peppermint oil has the most uses. It is used in foods, cosmetics, personal hygiene products, and pharmaceutical products. The oil relieves skin irritation and inflammation, reduces pain and nausea, and improves dental hygiene [1].
Snapshot
Proponents:
- Helps with IBS and gut spasms
- Relieves itching and headaches
- Improves digestion
- May enhance physical and mental performance
- May ease muscle pain
Skeptics:
- May cause heartburn
- May irritate the skin
- Can be toxic at higher doses
Constituents
Constituents of peppermint oil include [2, 3]:
- Menthol
- Menthone
- Pulegone
- Rosmarinic acid
- Limone
- Isomenthone
- Limonene
- β-myrcene
- Β-caryophyllene
- Carvone
Peppermint oil may also cause allergic reactions. It is also mildly toxic when ingested in large amounts. For the most part, peppermint oil is safe for normal use [2].
Peppermint Oil Benefits and Uses
Likely Effective:
1) Irritable bowel syndrome (IBS)
Irritable bowel syndrome (IBS) symptoms include stomach pain, cramping, gas, constipation, and diarrhea.
In different meta-analyses and clinical trials, enteric-coated peppermint oil was mildly effective at reducing IBS symptoms, especially flatulence and stomach pain [4, 5, 6, 7].
In one study, 57 IBS patients were treated with two enteric-coated capsules twice per day or a placebo. After four weeks, the patients in the peppermint oil group experienced relief from stomach pain, diarrhea, constipation, and bloating [5].
Up to 80% of IBS cases may be caused by small intestinal bacterial overgrowth (SIBO). Peppermint oil reduced intestinal hydrogen gas production in patients with bacterial overgrowth. It also reduced IBS symptoms related to abnormal intestinal gas production [5].
2) Itching
Severe itching of the skin can occur during pregnancy (pruritus gravidarum) in 1-8% of pregnant women. Most pregnant women avoid using synthetic drugs because of their potential side effects for the baby. The use of peppermint oil may be a safe alternative for treating severe itching.
In one clinical trial of 96 pregnant women, peppermint oil significantly reduced itching severity [8].
People recovering from burns also suffer from severe itching (pruritus). In one controlled study of 74 patients, a topical gel made with peppermint oil, menthol, and methyl salicylate helped relieve skin irritation [9].
Peppermint oil effectively reduced itching in 50 patients with liver disease, kidney disease, or diabetes [10].
3) Gut Spasms
Menthol is a major constituent of peppermint oil. Menthol peppermint oil relaxes muscles and prevents spasms by blocking calcium channels in muscles [11].
Peppermint oil helps reduce spasms during intestinal procedures. Administration of the oil through enema (injection through the rectum) reduced spasms during barium enema and colonoscopies in three clinical studies of more than 500 patients [12, 13, 14].
Peppermint oil is especially useful in stopping spasms in elderly patients during endoscopy, according to a large trial of over 8,000 patients [15].
4) Headache
Topical administration of peppermint oil directly onto the skin may be effective at reducing headaches. In one randomized control trial of 41 patients, 10% peppermint oil significantly reduced headache intensity. Peppermint oil was as effective as acetaminophen (an over-the-counter pain reliever, like Tylenol) at relieving the pain [4].
In another trial, 32 healthy subjects used a combination of peppermint oil, eucalyptus oil, and alcohol. They applied it to large areas of the forehead and temples. This combination of oils had a physically and mentally relaxing effect and reduced pain sensitivity. However, it did not reduce pain from migraines [16].
Insufficient Evidence:
No valid clinical evidence supports the use of peppermint oil for any of the conditions in this section. Below is a summary of up-to-date animal studies, cell-based research, or low-quality clinical trials which should spark further investigation. However, you shouldn’t interpret them as supportive of any health benefit.
5) Nausea and Vomiting
Both peppermint and spearmint essential oils help prevent chemotherapy-induced nausea and vomiting. In a randomized, double-blind clinical trial study, essential oil capsule administration reduced the intensity and occurrence of vomiting after chemotherapy [17].
Peppermint oil aromatherapy (inhalation) is another option for relieving nausea [18].
In one study of 18 gynecological surgery patients, peppermint oil aromatherapy helped reduce anesthesia-induced nausea. However, the sample size might be too small to draw a conclusion [19].
In another trial of 60 pregnant women, peppermint oil aromatherapy did not reduce nausea and vomiting. However, it did reduce nausea intensity [20].
More studies are needed to come to any definitive conclusions.
6) Indigestion (Dyspepsia)
Non-ulcer dyspepsia is another stomach condition. Its main symptoms include fullness, bloating, and stomach spasms.
A combination of enteric-coated peppermint oil and caraway oil reduced dyspepsia symptoms in four clinical trials of 373 total patients [21, 22, 23, 24].
In a trial of 12 healthy volunteers, a combination of peppermint and caraway oil helped relax the gallbladder [25].
However, caraway oil has well-known beneficial effects on digestion, and it likely contributed to the results.
Pure peppermint oil was not effective for dyspepsia following gynecological surgery in 69 women [26].
Further research should clarify the potential benefits of peppermint oil for indigestion as a stand-alone treatment.
Insufficient Evidence:
No valid clinical evidence supports the use of peppermint oil for any of the conditions in this section. Below is a summary of up-to-date animal studies, cell-based research, or low-quality clinical trials which should spark further investigation. However, you shouldn’t interpret them as supportive of any health benefit.
7) Infantile Colic
Infantile colic is hard to treat in babies and quite exhausting for their parents. Symptoms include long episodes of crying, irritability, or restlessness [27].
Researchers studied 30 infants suffering from colic in a study. The infants received formulas with peppermint oil drops for one week.
At the end of the study, there was a significant decrease in the frequency of daily episodes and the average crying time [27].
However, infantile colic symptoms usually resolve by themselves over time, and the therapeutic role of peppermint oil has yet to be determined.
8) Back and Muscle Pain
Low back pain is a major problem. Nonsteroidal anti-inflammatory drugs (NSAIDs) relieve pain symptoms, but their long-term use comes with certain health risks. Topical herbal remedies may be alternative therapies to NSAIDs [28].
According to clinical experience and traditional uses, topical application of wintergreen and peppermint oils may relieve pain. This combination is likely to have fewer side effects than conventional drugs [28].
Stroke patients who experience complete paralysis of half of the body suffer from shoulder pain from the weakening of shoulder muscles. A combination of lavender, rosemary, and peppermint oils aromatherapy helped 30 patients with this condition, when combined with acupressure [29].
These pain-relieving effects may be due to peppermint oil’s ability to relax the muscles and calm the mind. However, further trials are needed in order to draw definite conclusions.
9) Exercise Performance
Compared to the results of the initial treadmill test, 20 male students performed significantly better after peppermint oil supplementation (0.05 ml daily for 10 days). They also had a lower heart rate and blood pressure, and it took them longer to become exhausted [30].
In another study of 30 young men, the peppermint oil group had a significant increase in grip force, vertical jump, and long jump distance. They also had a decreased reaction time, heart rate, and breath rate. These changes were still effective after one hour [31].
A possible explanation for these results from both studies includes peppermint oil relaxing the smooth muscles, which helps boost performance. The oil might also reduce blood lactate levels and help the subject feel less tired [30, 31].
10) Cognitive Performance
In a study of 144 volunteers, inhaling peppermint oil helped enhance the participant’s scores on memory tests. The peppermint group had better recognition, faster attention, and overall better memory in comparison to the control group [32].
However, in a different study of 13 subjects, peppermint tea had no positive effects on memory enhancement [33].
In another study, researchers studied the effects of peppermint odor on the typing performance of 26 participants. There was a significant improvement in typing speed and accuracy when the patients were exposed to peppermint odor versus without the presence of an odor [34].
Therefore, the results of this study suggest that peppermint oil increases arousal and attention. This helped the participants focus on their tasks and increase performance [34].
However, in another study, peppermint essential oil aromatherapy had no influence on the speed and accuracy of answers in a vigilance task [35].
The conflicting effects of peppermint oil on cognitive performance require further investigation.
11) Oral Health
Peppermint essential oil has antimicrobial activity. In cell culture, it inhibited the growth of four common oral pathogens, which may improve oral health [36].
The peppermint plant also has an antibacterial effect. It helped kill and reduce the growth of various bacteria, including E.coli, S. aureus, etc. [37].
Additionally, peppermint oil increases salivation, which is beneficial because dry mouth can result in halitosis (bad breath) [36].
In a clinical trial of 84 students who suffered from bad breath, a peppermint mouth rinse reduced bad breath. It was more effective in comparison to the placebo. After a one-week trial, the prevalence of bad breath was reduced to 24.4% in the students [38].
Further research on the effects of peppermint oil on oral health is warranted.
Animal and Cellular Research (Lacking Evidence)
No clinical evidence supports the use of peppermint oil for any of the conditions listed in this section. Below is a summary of the existing animal and cell-based studies; they should guide further investigational efforts but should not be interpreted as supportive of any health benefit.
Hair Loss
In a study of male mice, researchers compared the hair growth effects of peppermint oil, saline, jojoba oil, and minoxidil. Topical application of 3% peppermint oil led to faster hair growth than any other solution. It was even more effective than minoxidil, which is an FDA-approved hair growth treatment [39].
After four weeks of topical application, peppermint oil-induced very thick and long hair in mice. These effects may be due to its ability to increase IGF-1 and alkaline phosphatase. The cellular production of IGF-1 supports cell growth and survival, which helps increase hair thickness [39].
Peppermint Oil Side Effects & Precautions
Both oral and topical applications of peppermint oil are likely safe for healthy adults and children. Possible side effects are mild and include [4, 1, 40]:
- Allergic reactions
- Dermatitis
- Nausea
- Heartburn
- Blurred vision
- Breathing problems
Extreme doses are associated with inflammation of the kidneys [4, 41].
The oil may increase the volume of secretion of bile and solids from the liver. Patients with gallstones and gallbladder inflammation should not use peppermint oil. Additionally, the use of oil can worsen a hernia and acid reflux symptoms [4].
Pregnant women and children should use peppermint oil under strict medical supervision only.
Peppermint oil interferes with cytochrome P450 enzyme activity. This means that it stops the body from breaking down certain drugs. However, this effect has not yet occurred in humans. To stay on the safe side, consult with your doctor before supplementing [42, 43].
Supplementation
Forms and Dosage
The below doses may not apply to you personally. If your doctor suggests using peppermint oil, work with them to find the optimal dosage according to your health condition and other factors.
In most IBS trials, the optimal dosage range was 0.2-0.4 mL, taken three times daily in enteric-coated capsules. Enteric-coated peppermint oil capsules pass through the stomach without dissolving. The capsules then disintegrate in the intestines [4].
Colpermin is an enteric-coated peppermint oil capsule. It contains around 0.2 ml of peppermint oil in each capsule. It gets rid of its enteric coat after 1.07 hours with a peak in 5 hours after administration [44, 45].
Mintec is another type of enteric-coated peppermint oil capsule. It starts releasing the oil after 30 minutes with a peak after 2.8 hours, which is faster than Colpermin [45].
User Reviews
The opinions expressed in this section are solely from the users who may or may not have a medical background. SelfDecode does not endorse any specific product, service, or treatment. Do not consider user experiences as medical advice. Never delay or disregard seeking professional medical advice because of something you have read on SelfDecode.
Plenty of users reported the benefits of peppermint oil and tea for IBS symptoms. Some of them claim it’s the only approach that helps.
People also use the oil to relieve headaches and nausea, and most of them report positive results. The most common side effect is heartburn.
