Uses of Mint: What Are the Potential Drawbacks?

Mint belongs to the Lamiaceae family and there are a great many varieties. The one most commonly used in herbal medicine is peppermint (Mentha piperita), a 17th-century hybrid of several mint species (M. aquatica, M. longifolia and M. rotundifolia). It is grown mainly for its leaves and for its essential oil, which is rich in menthol and menthone, two active compounds with antispasmodic, decongestant, and analgesic properties.

Peppermint is used in various forms: whole leaves, herbal tea, essential oil, dry extract, gastro-resistant capsules and cosmetic preparations. The effects and risks vary depending on the method of administration.

Good to Know: The traditional use of mint dates back to ancient times, but its modern medicinal applications have only been recognised for a few centuries. In recent years, the drawbacks of mint have been scientifically studied to minimise negative side effects as much as possible.

A Recognised Digestive Aid

Consuming peppermint is particularly recommended for digestive problems. Peppermint essential oil can act as an antispasmodic on the muscles of the digestive tract, which can sometimes help to reduce bloating, abdominal cramps and the symptoms of irritable bowel syndrome. Infusions made from dried leaves are used to relieve indigestion and flatulence.

Respiratory Support

Thanks to the menthol it contains, peppermint has a refreshing and decongestant effect. When inhaled, it helps to clear the airways during colds, coughs, or bronchitis. Its effect on cold receptors helps to soothe breathing and provides an immediate sense of relief.

A natural Pain-Relieving Effect

Peppermint essential oil is traditionally used to relieve headaches, muscle tension, and joint pain. When rubbed into the skin, its mild anaesthetic effect, combined with the cooling sensation it provides, helps to quickly reduce the perception of pain.

Helpful for Nausea

Clinical studies have shown that peppermint essential oil can reduce nausea, particularly during post-operative care or in cases of digestive disorders. This property is also utilised in certain capsules containing peppermint and caraway.

A Versatile Traditional Use

Beyond these scientifically validated benefits, peppermint has long been used to stimulate milk production, regulate menstrual cycles, or as a mild sedative. However, these uses remain traditional in nature and have not yet been confirmed by robust clinical studies.

• Antispasmodic Effect: May reduce intestinal spasms and relieve the symptoms of irritable bowel syndrome

• Digestive Relief: May help to relieve bloating, flatulence, symptoms associated with indigestion and nausea

• Respiratory Decongestant: Has a cooling and soothing effect on the respiratory tract

• Pain-Relieving Action: May help reduce headaches and muscle pain when applied to the skin

• Nausea Relief: Recognised benefits in certain clinical contexts (surgery, gastrointestinal disorders)

Digestive Irritation and Acid Reflux

One of the main drawbacks of peppermint lies in its side effects on the digestive system. Indeed, when peppermint essential oil comes into direct contact with the oesophagus or stomach, it can cause irritation to the mucous membranes. This results in heartburn or gastro-oesophageal reflux. To avoid these problems, peppermint essential oil must be encapsulated in enteric-coated capsules.

It is also worth noting that this effect is sometimes exacerbated by the regular consumption of mint tea.

Risks for Children

Peppermint can be dangerous for young children. In children under the age of two, it can cause a laryngeal spasm and trigger reflex apnoea. Cases of infantile convulsions have also been reported following exposure to cosmetics containing menthol. The use of products containing peppermint is therefore contraindicated in children under two years of age, not recommended for children aged two to four, and should be avoided by children prone to seizures.

Drug Interactions

Peppermint interferes with the metabolism of many medicines. In particular, it inhibits certain liver enzymes involved in the elimination of active substances, which can increase the blood concentration of these substances and, consequently, their side effects. It also reduces the effectiveness of certain cardiovascular treatments, such as calcium channel blockers. Anyone undergoing long-term treatment should consult a healthcare professional before starting a course of peppermint or consuming it regularly.

Risks Associated With Overdose

Among the drawbacks of mint, accidental overdose is very common. An overdose of essential oil can cause serious symptoms: skin rashes, headaches, a slowed heart rate, and dizziness. In severe cases, hospitalisation may be necessary. Older people are more susceptible to these adverse effects, as they are at increased risk of agitation and confusion.

Peppermint contains several bioactive compounds, the main ones being:

Menthol: Responsible for the cooling sensation, it acts as a local painkiller and decongestant

Menthone: Has antispasmodic and digestive properties

Flavonoids: Provide antioxidant properties

Phenolic Acids: Contribute to the anti-inflammatory effect

It is the synergy of these molecules that explains the plant’s varied effects, but also some of the side effects and drawbacks of mint.

To be classified as pharmaceutical and used in aromatherapy, peppermint essential oil must contain the following:

• 30–55% menthol

• 14–32% menthone

• 1.5 to 10% isomenthone

• 1–8% menthofuran

• 2.8–10% menthyl acetate

• 3.5–8% 1.8-cineole

• 1–3.5% limonene

• A maximum of 3% pulegone, 0.2% isopulegol and 1% carvone

• It is contraindicated in children under 7 years of age, and in people with epilepsy or asthma

• Not recommended in cases of bile duct obstruction, gallbladder inflammation, severe liver damage, or uncontrolled high blood pressure

• Should be avoided during the first trimester of pregnancy and while breastfeeding

• Caution is advised in cases of gallstones

• Do not exceed the recommended doses to avoid adverse effects

Peppermint tea is generally well tolerated. It can therefore be incorporated into most diets to help maintain a healthy digestive system. However, the essential oil must be handled with care. Indeed, one of the drawbacks of peppermint essential oil is that it must never be applied undiluted to large areas of skin, nor ingested without medical advice. Self-medication carries risks of interactions and overdoses, particularly in vulnerable individuals.