Background

Spearmint (Mentha spicata) is a species of mint plant. It's grown for its leaves and essential oil, which is used as a flavoring in foods and cosmetics.

Spearmint oil contains chemicals that reduce swelling and affect hormone levels in the body, including testosterone. Some chemicals might also harm cancer cells and kill bacteria.

People use spearmint for memory, digestion, osteoarthritis, nausea and vomiting after surgery, and many other conditions, but there is no good scientific evidence to support these uses.

Don't confuse spearmint with other plants known as mint, including English horsemint, Japanese mint, peppermint, perilla, salvia divinorum, or wild mint. These are not the same.

Safety Safety definitions

When taken by mouth: Spearmint and spearmint oil are commonly consumed in foods. Spearmint is possibly safe when used as a medicine, short-term. It's usually well tolerated.

When applied to the skin: Spearmint is possibly safe. It might cause an allergic reaction in some people, but this is rare.

Special Precautions & Warnings:

Pregnancy: Spearmint and spearmint oil are commonly consumed in foods. But spearmint is possibly unsafe when taken by mouth in large amounts during pregnancy. Very large doses of spearmint tea might damage the uterus. Avoid using large amounts of spearmint during pregnancy.

Breast-feeding: Spearmint and spearmint oil are commonly consumed in foods. There isn't enough reliable information to know if larger amounts of spearmint are safe when breast-feeding. Stay on the safe side and stick to food amounts.

Kidney disorders: Spearmint tea might increase kidney damage. Using large amounts of spearmint tea might make kidney disorders worse.

Liver disease: Spearmint tea might increase liver damage. Using large amounts of spearmint tea might make liver disease worse.

Effectiveness

Dosing & administration

Spearmint extract has most often been used by adults at a dose of 900 mg by mouth daily for up to 90 days. Spearmint tea has most often been used as two cups daily for up to 16 weeks. Speak with a healthcare provider to find out what dose might be best for a specific condition.

Interactions with pharmaceuticals

Medications that can harm the liver (Hepatotoxic drugs)

Interaction Rating=Moderate Be cautious with this combination.

Spearmint might harm the liver. Some medications can also harm the liver. Taking spearmint along with a medication that can harm the liver might increase the risk of liver damage.

Sedative medications (CNS depressants)

Interaction Rating=Moderate Be cautious with this combination.

Spearmint might cause sleepiness and slowed breathing. Some medications, called sedatives, can also cause sleepiness and slowed breathing. Taking spearmint with sedative medications might cause breathing problems and/or too much sleepiness.

Interactions with herbs & supplements

Herbs and supplements that might harm the liver: Spearmint might harm the liver. Taking it with other supplements that can also harm the liver might increase the risk of liver damage. Examples of supplements with this effect include garcinia, greater celandine, green tea extract, kava, and kratom.
Herbs and supplements with sedative properties: Spearmint might cause sleepiness and slowed breathing. Taking it along with other supplements with similar effects might cause too much sleepiness and/or slowed breathing in some people. Examples of supplements with this effect include hops, kava, L-tryptophan, melatonin, and valerian.

Interactions with foods

There are no known interactions with foods.