Lemon Balm Clinical Evidence

Psychosomatic Medicine

Kennedy D, Little W, and Scholey A. Attenuation of Laboratory-Induced Stress in Humans After Acute Administration of Melissa officinalis (Lemon Balm). 2004. 66:607–613.

Topic:
Can lemon balm help alleviate stress?

Background:
Lemon balm is a fragrant herb thought to have a mild sedative effect. Can it reduce acute stress?

Study Type:
Human clinical intervention trial

Study Design:
Double-blind, placebo-controlled, randomized, balanced, crossover study. Subjects took single doses of either lemon balm or a placebo on separate days, with a seven-day washout period. Their mood was assessed at baseline and 1 hour post-dose. In between, they completed a 20-minute stress-inducing test (Defined Intensity Stressor Simulation). Cognitive performance on the test was also measured.

Subjects:
18 healthy subjects

Dosage:
A single dose of 300 or 600 mg of lemon balm or placebo

Results:
In subjects taking the higher dose, lemon balm alleviated the negative mood induced by the test. These subjects’ self-ratings of calmness were significantly higher than other subjects’. Additionally, subjects taking the lower dose were significantly faster at the test, with no loss of accuracy.

Conclusion:
These results suggest that the potential of M. officinalis to mitigate the effects of stress deserves further investigation.

Lemon BalmMechanism of Action:

Lemon balm (Melissa officinalis) has several anti-stress actions. It decreases blood levels of corticosterone, a stress hormone implicated in depression, and it increases brain levels of GABA. Lemon balm contains significant amounts of rosmarinic acid and the triterpenoids oleanolic acid and ursolic acid, all of which inhibit the activity of GABA transaminase — an enzyme that breaks down GABA. As a result, these phyto-nutrients increase GABA levels in the brain and promote relaxation. Analysis has shown that rosmarinic acid is the major compound in lemon balm responsible for its GABA activity. It is found in large amounts in the crude herb and extract.