300–600 mg of extract; for sleep, at night.
Somewhat reduces anxiety and improves the feeling of calm.
View the study (RCT) →Possible mild relief of benign palpitations and digestive discomfort.
View the study (RCT) →⏱ 3 min read
Lemon balm, also known as toronjil or "hierba limón" (not to be confused with citronella), is Melissa officinalis, a Mediterranean member of the mint family with a characteristic citrus aroma that has been used in traditional European medicine since Greek and Roman antiquity as a mild tranquilizer, sleep improver, digestive aid, and to "gladden the heart"; the identified active constituents are essential oils with citral and citronellal, rosmarinic acid, flavonoids, and other phenolic compounds with documented activity on the central nervous system, gastrointestinal motility, and inflammatory processes.
Unlike more potent plants with a complicated safety profile (kava, valerian), lemon balm stands out for a combination of modest but replicable clinical effects on anxiety, sleep, and cognition with an exceptionally good safety profile and millennia of use without significant documented toxicities, which makes it a reasonable option for people seeking gentle modulation of mood and sleep without the risks of more aggressive medication.
Several small trials have shown significant improvements on anxiety and self-reported stress scales with doses of 300-600 milligrams per day of standardized extract for 2-4 weeks, an intervention consistent with its traditional use and with electroencephalographic data showing increased alpha waves (a marker of relaxation) after acute administration.
A randomized trial published in 2011 with healthy volunteers subjected to experimental cognitive stress showed that 600 mg of lemon balm extract significantly improved the subjective sense of calm and reduced markers of acute stress during a stressful task, with a favorable tolerability profile and no relevant cognitive impairment.
In mild functional insomnia, especially when associated with anticipatory anxiety or nighttime mental rumination, lemon balm (alone or combined with valerian) has shown significant improvements in subjective sleep quality in several small studies; the combination with valerian is a traditional European formulation with reasonable clinical data and a better tolerability profile than valerian alone (which produces residual morning drowsiness in some people).
In acute studies with healthy volunteers, lemon balm has shown significant improvements in memory, attention, and processing speed with single doses of 300-1,000 milligrams, a cognitive profile consistent with mild cholinergic activity documented in vitro; in patients with mild to moderate Alzheimer's disease, an Iranian trial published in 2003 showed significant improvements on cognitive and agitation scales with the extract over 4 months, an indication with preliminary clinical support but consistent with the mechanistic data.
In functional dyspepsia, abdominal colic, and gastrointestinal disorders with a spasmodic component or associated anxiety, lemon balm has traditionally been used with favorable subjective effects; modern clinical data are more limited but consistent with a mild antispasmodic effect and with improvement of the anxiety associated with functional discomfort.
Topically, 1 percent lemon balm extract applied in commercial creams has shown efficacy in recurrent cold sores, with reduced healing time and outbreak severity, attributed to direct antiviral activity against herpes simplex virus type 1 documented in vitro.
The doses studied range from 300 to 1,200 milligrams per day of standardized extract, divided into one or several doses; for anxiety and sleep, 300-600 mg/day divided; for acute use (occasional stress), 600-1,000 mg as a single dose; the traditional infusion (1-3 teaspoons of dried leaf per cup, 2-3 times a day) is a gentle and well-tolerated form; combinations with valerian, passionflower, or magnesium are common in commercial formulations.
Generally very well tolerated, with millennia of documented use; the adverse effects are rare and mild (daytime drowsiness if overdosed, occasionally digestive discomfort); people with hypothyroidism should take theoretical caution because in vitro data suggest that lemon balm may mildly inhibit TSH uptake (with no documented clinical relevance at usual doses, but caution is advisable); those taking pharmacological anxiolytics, sedatives, or hypnotics may experience mild potentiation of the sedative effect; in pregnancy and breastfeeding the data are limited, although it has traditionally been used as an infusion without problems at moderate doses; in children, a gentle infusion is well tolerated for mild colic or irritability.
Information, not medical advice. Scientific evidence reflects the quality of the studies.