Horse mint

What is Horse mint?

Horse mint is a tall wild mint used as a herbal tea in European folk medicine. Botanists call it Mentha longifolia. German speakers know it as Rossminze.

It grows along streams and ditches across Europe, North Africa and much of Asia. The leaves smell sharply of mint, though the scent varies a lot from plant to plant. Folk use centred on upset stomachs, wind, coughs and sore mouths.

It is a close relative of peppermint and spearmint, but it is not the same plant. Trial results for peppermint do not carry over to it. Its own make-up changes by region and season.

Here is the honest verdict. There are almost no human trials on horse mint itself. Most of what is published comes from test tubes and animals.

Long use in folk medicine is not proof that it works, and it is not proof that it is safe.

How does Horse mint work?

Nobody has shown in people how horse mint acts, or whether it acts at all.

The proposed ideas come from the lab. In test-tube work, the leaf oil relaxes strips of gut muscle taken from animals. That is the usual explanation offered for the old use in cramps and wind.

In laboratory dishes the oil also slows the growth of several bacteria and fungi. Whether this happens in a human gut, mouth or on skin is not established.

The leaf holds rosmarinic acid and flavonoids. In cell studies these mop up reactive molecules and damp down some markers of swelling. Antioxidant activity in a dish does not mean a health effect in a person.

A few animal studies report lower blood sugar and lower blood pressure after extracts. These were rodents, at doses far above a cup of tea. Treat them as leads, not findings.

What forms does Horse mint come in?

Most people meet horse mint as a dried leaf tea.

Forms on sale or in home use:

- Dried loose leaf and tea bags, sometimes blended with other mints. - Fresh leaf, picked wild or grown in gardens. - Tinctures (alcohol extracts), sold by some herbal suppliers.

- Essential oil, steam-distilled from the leaf. - Bath and foot-soak preparations. - Flavouring in regional cooking, drinks and yoghurt dishes.

The oil is a different proposition from the tea. It is far stronger, and the pulegone is concentrated in it. It is sold for scent and external use, not for swallowing.

Labelling is often loose. A pack may say only "wild mint", which can cover several species.

Where it comes from:

Horse mint has a long record in European country medicine, going back to the classical herbals.

Village use centred on the stomach. Writers recorded the tea for wind, bloating, colic and queasiness after heavy food. It was also drunk for colds and chesty coughs.

Other recorded uses were external. Crushed leaves were laid on insect bites and itchy skin. Strong infusions were used as a mouth rinse and as a bath for aching feet.

It earned its name from livestock, not from people. Farmers used it around horses and stables, partly as a strewing herb against flies.

In North Africa, the Balkans and the Middle East, the same plant entered local cooking and home remedies. None of this record was gathered as research, and none of it tested safety.

What does Horse mint help with?

• Wind, bloating and mild stomach cramps: This is the oldest and best-known folk use. The tea was drunk after meals to settle the gut. The lab support is indirect. Mint oils relax animal gut muscle in test-tube work. No trial has tested horse mint tea in people with bloating. Peppermint oil capsules do have trial evidence in irritable bowel syndrome. That is a different species in a different form. It does not transfer.
• Mild nausea: Tradition used mint tea and the smell of crushed leaves for queasiness. There is no human trial of horse mint for nausea. Some small trials of other mint scents give mixed and weak results. If nausea is new, severe, or comes with pain or vomiting blood, that needs a doctor, not a tea.
• Coughs and head colds: Hot mint tea and steam were standard home care for a blocked nose and a tickly cough. Warm fluid and steam can feel better in the short term. That comfort is not the same as shortening the illness. No study shows horse mint clears a cold faster. Never use mint oil on or near the face of a baby or young child.
• Mouth rinse for sore gums and bad breath: Cooled strong infusions were swilled for sore gums, mouth ulcers and stale breath. In test tubes, horse mint extracts slow some mouth bacteria. Whether a rinse does the same in a real mouth has not been shown. Any mint rinse may freshen breath briefly. That is a flavour effect, not treatment of gum disease.
• Itchy skin and insect bites: Crushed leaves and cool washes were applied to bites, stings and itchy patches. A cooling feel is plausible where menthol is present. There are no human trials of horse mint for itch. Undiluted oil on skin can burn or sensitise. Broken or weeping skin is not a place for it.
• Period cramps: Some European and Middle Eastern folk practice used mint teas for cramping periods. Evidence for horse mint here is absent in humans. The idea rests on the gut muscle work in animals. Heavy, worsening or disabling period pain should be looked at by a clinician.

Which foods are rich in Horse mint?

Horse mint is a herb, not a nutrient, so no food is "rich in it". The leaf itself is used fresh or dried as a flavour in teas, yoghurt dishes, salads and stews in parts of the Balkans, North Africa and the Middle East. Culinary amounts are small and are treated as food rather than medicine.

What are the side effects of Horse mint?

• Heartburn or reflux, as mint can relax the valve at the top of the stomach
• Nausea from very strong brews
• Mouth or throat irritation
• Allergic rash or itching in people sensitive to mint family plants
• Skin burning or redness from undiluted oil
• Headache or dizziness after strong preparations
• Liver injury, reported with high-dose pulegone-rich mint oils, not with ordinary tea

Good to know:

Horse mint tea in food-like amounts is generally well tolerated. Reflux is the most common complaint.

The serious risks sit with the essential oil, not the cup of tea. Swallowed pulegone-rich mint oils have caused liver damage and fits in reported poisonings.

Stop and get advice if you develop a rash, yellow skin or eyes, dark urine, bad stomach pain or any unexplained weakness.

How much Horse mint should you take?

• Recommended daily: Horse mint tea is usually treated like any other mint tea on a label. Packs commonly state about 1 to 2 grams of dried leaf per cup, up to two or three cups a day. That is what labels carry. It is not advice for you, and your own limit may be lower. No safe swallowed dose of horse mint essential oil can be given. The pulegone content is unknown and variable, and pulegone harms the liver in animals at high doses. Do not drink it or put it in capsules. Anyone pregnant, breastfeeding, under 12, or living with liver or kidney disease should get a dose question answered by a doctor or pharmacist, not by a pack.
• Best time of day: Timing is a matter of comfort, not of effect. For wind and fullness, tradition put it after meals. For sleep-time comfort, people drink it in the evening. If you get heartburn, late-evening mint is the worst choice. Mint can relax the valve at the top of the stomach and let acid rise.
• With or without food: Most people drink it after food, and that suits the traditional use for fullness and wind. On an empty stomach it is usually tolerated, but it can feel harsh if you are prone to reflux. Space it a couple of hours from iron tablets. The tannins in mint tea can cut how much iron you absorb.
• Time to effect: If a cup of mint tea is going to help, it tends to feel soothing within the hour. Much of that is likely the warm fluid, the rest and the smell. That is still real comfort, but it is not proof of a drug effect. It may also do nothing at all. There is no human evidence that horse mint changes the course of any condition.
• How long to take it: Short runs are the usual pattern, not daily use for months. Folk use was occasional: a cup after a heavy meal, or a few days during a cold. Long unbroken use has never been studied for safety in people. Because pulegone levels vary and build-up cannot be ruled out, heavy daily drinking over long periods is not a good idea. If a symptom needs weeks of treatment, it needs a diagnosis.