A systematic review and meta-analysis published in 2021 found that, based on qualifying randomized clinical trials from 12 online databases, Lemon Balm may be effective in improving symptoms of anxiety and depression without the risk of serious side effects. The authors noted that, despite promising findings, additional high-quality studies are needed to better understand the clinical applications and efficacy of Lemon Balm.
A 2023 double-blind clinical trial examined the effects of Lemon Balm on depression, anxiety and sleep quality among participants with type 2 diabetes. (Rates of depression and anxiety, the study’s authors note, are higher among diabetic patients than the general population.) Over the course of the 12-week study, the intervention group consumed Lemon Balm in capsule form, while the control group took a placebo. No significant differences were observed in sleep quality, but researchers did find that participants who took Lemon Balm experienced a remarkable decrease in depression and anxiety.
A randomized, double-blind clinical trial published in 2021 studied the effects of Lemon Balm combined with fennel fruit extract on postmenopausal women experiencing sleep disturbance.
Participants who ingested the Lemon Balm blend for eight weeks received better scores in terms of their overall quality of life than those who received a placebo or citalopram, a prescription antidepressant.
A 2003 study suggests Lemon Balm may help improve cognitive function in older adults with mild to moderate Alzheimer’s disease. The parallel-group, placebo-controlled trial found that, after four months of consuming Lemon Balm daily, members of the intervention group significantly improved their scores on the Alzheimer's disease assessment scale (ADAS-cog) and the clinical dementia rating (CDR). Additionally, the intervention group experienced less agitation than the placebo group, suggesting that Alzheimer’s patients may also benefit from Lemon Balm’s calming effects.
Research dating back to 1999, suggests that Lemon Balm may be an effective treatment for herpes simplex, the virus that causes cold sores. In a double-blind, placebo-controlled, randomized trial, participants with a history of recurring cold sores applied Lemon Balm cream to the affected area four times a day over the course of five days. Compared to those who were given a placebo, individuals who used the Lemon Balm treatment experienced a shortened healing period, less spreading of the infection, and fewer painful symptoms.
One small study found that participants with persistent dyspepsia (stomach pain) experienced fewer and less intense dyspeptic episodes after eating a Lemon Balm-infused dessert than when they ate the same dessert sans Lemon Balm. However, the study authors note that the Lemon Balm was part of a blend that contained other potentially stomach-soothing herbs, so further research is required.
