Lemon balm’s common name describes it well. The leaves of Melissa officinalis have a lemony scent when crushed,1 and, as a member of the mint family, it is considered a calming herb, hence the balm.2
Also called sweet balm, dropsy plant, and honey plant, lemon balm is indigenous to southern Europe but also grows in warmer areas of England.3 English herbalist John Evelyn (1620-1706) once wrote, “Balm is sovereign for the brain, strengthening the memory, and powerfully chasing away melancholy.”2 In more clinical language, a balm is antispasmodic, calmative, carminative, and diaphoretic.3
Background
Lemon balm is found in a wide array of products, including medicines, food flavorings, teas, and cosmetics.1 Fresh or dried, it is often used to make infusions of cooking oils and in salad dressings. Creative, gourmet flavors—as well as added health benefits—can be achieved by mixing it with various herbs.
Continue Reading
This perennial plant grows in clumps and propagates by root and underground runner, as well as by seeds. It can actually become a nuisance in favorable climates.1 Established vegetation can grow up to two feet tall and produces small, light yellow flowers in clusters of dark green to light yellow-green leaves.2
Frequently found in commercial products combined with other calmative herbs, such as valerian, hops, and chamomile, lemon balm is recommended for anxiety, insomnia, indigestion, and other nerve-related conditions.2
Evidence of effectiveness
Lemon balm supplements are made from the leaves of the plant, where the essential oil is found.2 The active ingredients are terpenes. They are responsible for the oil’s relaxing and purported antiviral effects.3 The essential oil also contains eugenol, which is known to calm muscle spasms, numb tissues, and even kill some bacteria.2
If used topically, lemon balm’s aromatic leaves have an anti-infective property and promote healing. The terpene complexes in the leaves release ozone, which inhibits tissue necrosis, and since they are hydrocarbons, they contain so little oxygen that aerobic bacteria are literally asphyxiated.3
Melissa officinalis is most known for its ability to calm anxiety. These behavioral consequences may be attributed to the known active components of the dried leaf, i.e., the terpene and eugenol essential oils. Several studies verify lemon balm’s sedative, “calming” effects.4
Researchers at the University of Northumbria in the United Kingdom conducted a double-blind experiment in 2004. They gave 18 healthy volunteers 300 mg or 600 mg of a standardized lemon balm extract or a placebo seven days apart. The subjects were evaluated before dosing and one hour after for mood and cognition, based on their performance on a 20-minute version of the Defined Intensity Stress Simulation (DISS) battery. When taking the 600-mg dose, participants reported significantly less anxiety and greater alertness than when assigned to the other two doses.5
Lemon balm extract also has an antiviral effect and is often prescribed topically for infections such as cold sores. The efficacy of this therapy was tested in a study of 116 people with herpes simplex virus (HSV) infections.6 Lemon balm cream applied to their lip sores several times daily significantly reduced pain and swelling after only two days. Some subjects reported relief in as little as four hours.3,6
In addition, lemon balm is being studied as a therapy to improve cognitive function in patients suffering from dementia. Early trials led by the research team at the University of Northumbria indicate that the reduction of agitation noted from the lemon balm extract was accompanied by an overall improvement in cognitive function. The researchers attributed this result to the direct effect of lemon balm on the acetylcholine receptor activity, including the nicotinic and muscarinic receptors.4
How supplied
Lemon balm is available in bulk as dried leaves, but it is more commonly purchased in capsules, extracts, tinctures, and as essential oil.3 Capsules come in 300- to 600-mg strengths. Although several clinical studies rely on weekly doses, the usual recommended frequency is three times daily.1
Therapeutic teas should be brewed using one- quarter to one full teaspoon of dried leaves per cup and may be drunk up to four times daily.2 As a topical treatment for cold sores, brew a strong tea and apply with cotton balls throughout the day.2
Safety and side effects
Some potential for interaction with thyroid medication has been noted, and the use of lemon balm concomitantly with other central nervous system depressants could have a synergistic effect. If your patients are using lemon balm, an accurate medication review should be conducted.2
Allergic reaction is always possible with any botanical product, so patch testing is advisable before either oral or topical use. Apply lemon balm leaf or essential oil to a half-inch site on the inner forearm and cover with a dressing for 24 hours. If no redness or rash appears, consider the herb safe to use.
Because safety has not been established in pregnant or lactating women, lemon balm is not recommended for this population, but limited studies show safety in pediatric patients.1
Summary
Though there is still very little scientific evidence for therapeutic value, lemon balm appears to be a pleasant, mildly effective product for easing mild anxiety and enhancing cognitive acuity. As research proceeds, the effects of lemon balm on mood and cognitive function show promise.
A cup of lemon balm tea may be moderately calming, but it probably will not be efficacious in cases of clinical anxiety. However, for a simple, relaxing pleasure at the end of a busy day, it may be the ideal herb.
References
1. Simon JE, Chadwick AF, Craker LE. Herbs: An Indexed Bibliography, 1971-1980: The Scientific Literature on Selected Herbs, and Aromatic and Medicinal Plants of the Temperate Zone. Hamden, Conn.: Archon Books;1984:56.
2. Lemon balm. University of Maryland Medical Center.
3. Skidmore-Roth L. Mosby’s Handbook of Herbs & Natural Supplements. 3rd ed. St. Louis, Mo.: Elsevier Mosby;2006:650.
4. Kennedy DO, Wake G, Savelev S, et al. Modulation of mood and cognitive performance following acute administration of single doses of Melissa officinalis (Lemon balm) with human CNS nicotinic and muscarinic receptor-binding properties. Neuropsychopharmacology. 2003;28:1871-1881.
5. Kennedy DO, Little W, Scholey AB. Attenuation of laboratory-induced stress in humans after acute administration of Melissa officinalis (Lemon Balm). Psychosom Med. 2004;66:607-613.
6. Gaby AR. Natural remedies for Herpes simplex. Altern Med Rev. 2006;11:93-101.
All electronic documents accessed February 10, 2009.
