Background

Lemon balm (Melissa officinalis) is an herb from the mint family. The leaves, which have a mild lemon aroma, are used to make medicine and flavor foods.

Lemon balm contains chemicals that seem to have a sedative and calming effect. It might also reduce the growth of some viruses and bacteria.

People use lemon balm for cold sores, anxiety, stress, insomnia, indigestion, dementia, and many other conditions, but there is no good scientific evidence to support many of these uses.

Safety Safety definitions

When taken by mouth: Lemon balm is likely safe when consumed in amounts found in foods. Lemon balm supplements are possibly safe when used at a dose of up to 500 mg daily for up to 6 months. Side effects are generally mild and might include increased appetite, nausea, dizziness, and wheezing. There isn't enough reliable information to know if lemon balm is safe to use for more than 6 months.

When applied to the skin: Lemon balm is possibly safe for most adults. It may cause skin irritation.

Special Precautions & Warnings:

Pregnancy and breast-feeding: There isn't enough reliable information to know if lemon balm is safe to use when pregnant or breast-feeding. Stay on the safe side and avoid use.

Children: Lemon balm is possibly safe when taken by mouth by children for about one month.

Surgery: Lemon balm might cause too much drowsiness if combined with medications used during and after surgery. Stop using lemon balm at least 2 weeks before a scheduled surgery.

Thyroid disease: Lemon balm may change thyroid function, reduce thyroid hormone levels, and interfere with thyroid hormone replacement therapy. Avoid lemon balm if you have thyroid disease.

Effectiveness

Dosing & administration

Lemon balm is available in many forms, including supplements, combination products, lotions, ointments, massage oils, and others. There isn't enough reliable information to know what an appropriate dose of lemon balm might be. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult a healthcare professional before using.

Interactions with pharmaceuticals

Sedative medications (CNS depressants)

Interaction Rating=Moderate Be cautious with this combination.

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

Thyroid hormone

Interaction Rating=Moderate Be cautious with this combination.

Taking lemon balm seems to decrease how well thyroid hormone works in the body. Taking lemon balm with thyroid hormone might decrease the effects of the thyroid hormone.

Interactions with herbs & supplements

Herbs and supplements with sedative properties: Lemon balm 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.
Herbs with thyroid activity: Lemon balm might affect the body's production of thyroid hormone. Taking it with other supplements with similar effects might alter thyroid function too much and cause side effects. Examples of supplements with this effect include bugleweed and tiratricol.

Interactions with foods

Taking lemon balm with alcohol might increase sleepiness. But it's not clear if this is a big concern.