There’s evidence that lemon balm supplementation may reduce (improve) total cholesterol levels. It might also reduce LDL cholesterol and triglycerides in people with cardiometabolic conditions. The evidence is strongest for a small improvement to the total blood cholesterol level and mixed for LDL cholesterol and triglycerides.
A 2024 meta-analysis found that supplementation with lemon balm reduced total cholesterol, LDL cholesterol, and triglycerides, compared to a placebo. The included studies ran from 8–24 weeks, and lemon balm was given as leaf, powder, or tea in doses ranging from 700 mg/day to 4 grams/day. The effect size was small to moderate for triglycerides and total cholesterol and small for LDL cholesterol.[1] However, all the studies in this meta-analysis were in people with cardiometabolic conditions (type 2 diabetes, high cholesterol, chronic stable angina, premature ventricular contractions, or nonalcoholic fatty liver disease), so it’s not clear whether the results would apply to people with no diagnosed health conditions.
An earlier 2020 meta-analysis which did include some studies in people with no known health conditions, along with studies in people with cardiometabolic disorders, also found a small reduction in total cholesterol with lemon balm supplementation, particularly in shorter trials or those with a larger dose of lemon balm. In contrast to the 2024 meta-analysis above, the 2020 meta-analysis didn’t find any significant reductions in LDL cholesterol or triglycerides.[2] However, these interventions were shorter (6 to 12 weeks), and most of the included studies had a high risk of bias. Neither meta-analysis found any significant effect of lemon balm on HDL cholesterol.