Lemon balm (Melissa officinalis), not to be confused with bee balm, Monarda species, is a perennial herb in the mint family Lamiaceae, native to southern Europe and the Mediterranean region.
It grows to 70–150 cm tall. The leaves have a gentle lemon scent, related to mint. During summer, small white flowers full of nectar appear. These attract bees, hence the genus name Melissa (Greek for ‘honey bee’). Its flavour comes from citronellal (24%), geranial (16%), linalyl acetate (12%) and caryophyllene (12%).
This herb can be easy to cultivate in Plant Hardiness Zones 4 to 9 according to the United States Department of Agriculture. In zone 4, it needs well-drained sandy soil and a winter mulch or adequate snowcover to survive. In zone 7, it can be harvested at least until the end of November. While it prefers full sun (as described on most plant tags), it is moderately shade-tolerant, much more so than most herbs. In dry climates, it grows best in partial shade. It can also be easily grown as an indoor potted herb.
In North America, Melissa officinalis has escaped cultivation and spread into the wild.
Lemon balm requires light and at least 20 degrees Celsius (70 degrees Fahrenheit) to germinate, so it is best to plant indoors or in spring and not to cover the seeds.
Lemon balm grows in clumps and spreads vegetatively as well as by seed. In mild temperate zones, the stems of the plant die off at the start of the winter, but shoot up again in spring. It can be easily grown from stem cuttings rooted in water, or from seeds. Under ideal conditions, it will seed itself prolifically and can become a nuisance in gardens.
Melissa officinalis may be the “honey-leaf” (μελισσόφυλλον) mentioned by Theophrastus. It was in the herbal garden of John Gerard, 1596. There are many cultivars of Melissa officinalis, such as:
- M. officinalis ‘Citronella’
- M. officinalis ‘Lemonella’
- M. officinalis ‘Quedlinburger’
- M. officinalis ‘Lime’
- M. officinalis ‘Variegata’
- M. officinalis ‘Aurea’
(M. officinalis ‘Quedlinburger Niederliegende’ is an Improved variety bred for high essential oil content.)
Lemon balm is often used as a flavouring in ice cream and herbal teas, both hot and iced, often in combination with other herbs such as spearmint. It is also frequently paired with fruit dishes or candies. It can be used in fish dishes and is the key ingredient in lemon balm pesto. It has been suggested that it might be a better, healthier preservative than beta hydroxy acid in sausages.
The crushed leaves, when rubbed on the skin, are used as a repellant for mosquitos.
Lemon balm is also used medicinally as an herbal tea, or in extract form. It is claimed to have antibacterial and antiviral properties (it is effective against herpes simplex).
It is also used as an anxiolytic, mild sedative or calming agent. At least one study has found it to be effective at reducing stress, although the study’s authors call for further research. Lemon balm extract was identified as a potent inhibitor of GABA transaminase, which explains anxiolytic effects. The major compound responsible for GABA transaminase inhibition activity in lemon balm is rosmarinic acid.
Lemon balm and preparations thereof also have been shown to improve mood and mental performance. These effects are believed to involve muscarinic and nicotinic acetylcholine receptors. Positive results have been achieved in a small clinical trial involving Alzheimer patients with mild to moderate symptoms.
Its antibacterial properties have also been demonstrated scientifically, although they are markedly weaker than those from a number of other plants studied. The extract of lemon balm was also found to have exceptionally high antioxidant activity.
Lemon balm is mentioned in the scientific journal Endocrinology, where it is explained that Melissa officinalis exhibits antithyrotropic activity, inhibiting TSH from attaching to TSH receptors, hence making it of possible use in the treatment of Graves’ disease or hyperthyroidism.
Lemon balm essential oil is very popular in aromatherapy. The essential oil is commonly co-distilled with lemon oil, citronella oil, or other oils.
Lemon balm is used in some variations of the Colgate Herbal toothpaste for its soothing and aromatic properties.
Lemon balm should be avoided by those on thyroid medication (such as thyroxine), as it is believed the herb inhibits the absorption of this medicine.
Despite extensive traditional medicinal use, melissa oil was initially prohibited by the International Fragrance Association (IFRA)’s 43rd amendment, but this restriction appears to have been revisited and relaxed in the 44th amendment.
One traditional use of lemon balm tea was in extending age, although this effect has not been proven.Ob-X, a mixture of three herbs, Morus alba, M. officinalis, and Artemisia capillaris, may help regulate obesity. Ob-X reduces body weight gain and visceral adipose tissue mass in genetically obese mice.
Recent research found a daily dose of the tea reduced oxidative stress status in radiology staff that were exposed to persistent low-dose radiation during work. After only 30 days of taking the tea daily researchers found Lemon balm tea resulted in a significant improvement in plasma levels of catalase, superoxide dismutase, and glutathione peroxidase and a marked reduction in plasma DNA damage, myeloperoxidase, and lipid peroxidation.
Lemon balm was found to be effective in the amelioration of laboratory-induced stress in human subjects, producing “significantly increased self-ratings of calmness and reduced self-ratings of alertness.” The authors further report a “significant increase in the speed of mathematical processing, with no reduction in accuracy” following the administration of a 300 mg dose.
Lemon balm contains eugenol, which kills bacteria and has been shown to calm muscles and numb tissues. It also contains tannins that contribute to its antiviral effects, as well as terpenes that add to its soothing effects.
Melissa officinalis also contains 1-octen-3-ol, 10-alpha-cadinol, 3-octanol, 3-octanone, alpha-cubebene, alpha-humulene, beta-bourbonene, caffeic acid, caryophyllene, caryophyllene oxide, catechinene, chlorogenic acid, cis-3-hexenol, cis-ocimene, citral A, citral B, citronellal, copaene, delta-cadinene, eugenyl acetate, gamma-cadinene, geranial, geraniol, geranyl acetate, germacrene D, isogeranial, linalool, luteolin-7-glucoside, methylheptenone, neral, nerol, octyl benzoate, oleanolic acid, pomolic acid, protocatechuic acid, rhamnazine, rosmarinic acid, rosmarinin acid, stachyose, succinic acid, thymol, trans-ocimene and ursolic acid.
Lemon balm essential oil is colorless to pale yellow liquid displaying a rich, sweet green, herbaceous bouquet with a soft floral, citrus undertone
In natural perfumery used in aromatherapy creations, high class colognes, citrus accords, herbaceous notes.