Lemon balm is a rich source of antioxidant phenolic compounds,^[42][50] but its leaves have a relatively low essential oil content for a plant in the mint family, ranging from 0.01 to 0.72% of dry weight,^[17] with a tea extracting 10 mg/L.^[61] Because of the herb’s low content of volatile essential oil, the herb may be best used within six months of harvest.^[22]

Leaves: The dried leaves contain many polyphenols, notably rosmarinic acid, caffeic acid, chlorogenic acid, ferulic acid, isoquercetin (a glucoside of quercetin), gallic acid, and rutin; they also contain several triterpenes, notably oleanolic acid and ursolic acid.^[17] Lemon balm extracts use different solvents and different methods of extraction, which results in widely varying compositions.

Essential oil: There are two subspecies of lemon balm, M. officinalis officinalis and M. officinalis altissima, which differ in the composition of their essential oils: The oil of the officinalis subspecies contains important amounts of citral and/or neral, whereas these are only present in small quantities in the oil of the altissima subspecies. The composition of the essential oil also varies depending on where the plant is grown and the season in which the leaves are harvested. That said, the principal constituents of M. officinalis essential oil are as follows:^[17]

Taken from: Petrisor G et al. Melissa officinalis: Composition, Pharmacological Effects and Derived Release Systems – A Review. Int J Mol Sci. 2022 Mar 25;23(7):3591. doi:10.3390/ijms23073591.

As a traditional food plant and herbal medicine in many cultures, lemon balm has picked up a bevy of common names, and not all of them line up with our modern botanical definition of the species. In addition to the names listed as “also known as” on our lemon balm page, which are exclusively used for lemon balm, there are several common names that sometimes refer to lemon balm and sometimes to other plants. These include:

• Balm mint
• Mountain balm
• Balm
• Garden balm
• Lemon mint
• Badranjbuye
• Baadranjboyaa
• Billilotan
• Honey balm
• Faranjmoshk

These common names often refer to lemon balm, but they’re also sometimes used to refer to other plants, mostly in the mint family. For example, “billilotan” can refer to lemon balm (Melissa officinalis), catnip (Nepeta cataria), or Nepeta hindostana.^[22] Similarly, faranjmoshk is sometimes taken to mean lemon balm, but one study of Iranian herbal markets found that faranjmoshk seeds were actually Clinopodium graveolens.^[62] And although “honey balm” is often listed as a synonym for lemon balm,^[63] some plant sellers market the unfortunately named bastard balm (Melittis melissophyllum) under the more palatable name of honey balm.^[64] When considering an herb or herbal product sold under any of these names, always check to make sure it’s the desired botanical.

Lemon balm appears to reduce anxiety substantially, according to a 2021 meta-analysis of randomized clinical trials, although there wasn’t good agreement on the effect size between the studies included in the meta-analysis. Lemon balm may be more effective for immediate or situational (acute) anxiety than for long-term (chronic) anxiety. In the reviewed studies, lemon balm decreased acute anxiety in hospitalized patients with burns, acute coronary artery syndrome, and coronary artery bypass grafts, as well as in teenage girls with PMS, with an overall large effect size; it also decreased chronic anxiety in office workers and hospitalized patients with chronic stable angina, with an overall moderate effect size.^[12] However, there was a high risk of bias in most of the studies; more high-quality research is needed.

Based on the available evidence, lemon balm may also be useful for depression. The same 2021 meta-analysis found that there was a moderate reduction in depression with lemon balm. There were only three studies included in the analysis, but all the included studies showed similar results for short-term (acute) and long-term (chronic) depression.^[12] Again, more high-quality research is needed to confirm lemon balm’s usefulness for depression.

Lemon balm may also have benefits for sleep quality, especially in the contexts of depression, anxiety, stress, and anxiety-provoking heart conditions (chronic stable angina, benign palpitations, coronary bypass surgery). Multiple studies have evaluated lemon balm’s effect on sleep quality and onset in these contexts, finding that supplementation with lemon balm increased sleep quality scores^[25][4][26] and sleep duration,^[27] reduced insomnia,^[3][23] and hastened sleep onset.^[27] These effects may be due to anxiety reduction, as anxiety contributes to sleep problems. To date, the evidence supports the use of lemon balm for sleep in the context of anxiety, stress, depression or anxiety-provoking health conditions, but more research is needed to determine whether lemon balm can help with general insomnia.

Lemon balm has also been studied in combination with other herbs, such as valerian, for sleep;^[51][52][53] however, it’s not clear how much of the effect in these trials is due to lemon balm.

There are two types of herpes simplex virus (HSV): HSV-1 and HSV-2. Following the initial infection, HSV often becomes chronic, causing recurrent outbreaks of sores in either the oral or genital areas. Oral herpes is typically, but not always, caused by HSV-1; genital herpes is typically, but not always, caused by HSV-2. The sores (in oral herpes, “cold sores”) are often preceded by a tingling sensation, followed by blistering, which can be quite painful. The sores will resolve on their own without treatment in 2 to 3 weeks. There is no cure for HSV infection, but the duration of the sores can be reduced by treatment with oral or topical (applied to the skin) antiviral medication at the first sign of an outbreak; in people who have frequent outbreaks or are immunocompromised, the frequency of outbreaks may be reduced with longer courses of oral antivirals.^[54][55]

Many people with HSV use a commercial over-the-counter cream containing 1% dried lemon balm extract to treat oral or genital herpes sores.^[56] Two randomized, placebo-controlled trials of lemon balm cream for herpes sores have been published in English; the cream was moderately effective compared to the placebo.^[10][33][34] The first one, a 1994 trial in Germany in 115 people with oral or genital herpes who applied either 1% lemon balm cream or a placebo to the affected skin 2–4 times daily for 5–10 days, found that the cream reduced second-day redness and swelling, but not scabbing, lesion size, the number of blisters, or pain, compared to the placebo; additionally, more participants in the lemon balm group were judged to have healed well by 5 days than in the placebo group.^[34] The second, a 1999 trial in Bulgaria in 66 people with oral herpes who applied either lemon balm cream or a placebo 4 times a day for 5 days, found that the people who used the lemon balm had lower combined symptom scores on day 2 than people using the placebo, but the difference by day 5 was not significant.^[33] To summarize, based on the limited available research, lemon balm cream appears to be moderately effective for HSV sores and may ease the course of an outbreak.

Not much research has directly compared lemon balm to prescription antiviral medications. Topical lemon balm may be better at reducing pain than topical acyclovir, but slower to promote healing, according to a 2015 study in 60 people in Iran with oral herpes. The study compared the effectiveness of applying a lemon balm gel to the affected areas for seven days to that of applying acyclovir 5% cream. Both groups of participants had similar reductions in lesion size after seven days, but the lemon balm group reported less pain, and the lesions in the acyclovir group shrank much more quickly.^[11] However, it’s unclear from the study’s write-up when the treatments were applied — treatment is most effective before blisters appear, or at the latest within 48 hours of their appearance^[57] — or how often they were applied. Furthermore, oral antiviral medications are more effective than topical ones^[57] and are currently the standard of care for oral herpes.^[54] Although more research is needed, the current picture favors prescription oral antivirals over lemon balm.

Lemon balm has not been clinically studied for any of the many other manifestations of HSV infection, and should not be used to treat them. Other manifestations of herpes, including but not limited to ocular (eye) HSV, neonatal herpes, herpes encephalitis, and chronic severe HSV, can be serious and even fatal;^[54] medical attention should be sought.

There is very little human research on this front. A few randomized controlled trials in Iran have investigated lemon balm for psoriasis, itching after a burn, and oral lichenoid lesions.

Postburn itching: A 2019 study in hospitalized burn patients in Iran found that the participants who drank lemon balm tea twice daily, with snacks, reported less itching in the third week after the burn than the participants who didn’t drink lemon balm tea.^[58] However, this study had methodological and reporting issues, with a risk of bias in multiple areas.^[35]

Psoriasis: A study conducted in Iran in 2021 found that taking a syrup of lemon balm, Rosa damascena, and dates three times a day decreased disease severity and itching in people with psoriasis.^[36] Research in mice reported that a lemon balm decoction might help psoriasis by reducing dryness and improving the skin’s barrier function.^[59] More research in humans is needed.

Lichenoid lesions: A 2022 trial in Iran compared a lemon balm cream to triamcinolone paste (a topical steroid) for the treatment of erosive oral lichenoid lesions (inflamed patches in the mouth with a characteristic appearance), including oral lichen planus, drug-induced lichenoid reactions, and contact or transplant lichenoid reactions. The participants who used the lemon balm gel reported a greater reduction in pain compared to triamcinolone but had less of a reduction in lesion size.^[37]

Several randomized controlled trials in Iran have looked at lemon balm’s effectiveness for the symptoms of premenstrual syndrome (PMS), finding greater reductions in PMS symptoms with lemon balm than with a placebo. However, the existing research is of fairly low quality, and all the trials have been in young Iranian women; higher-quality research in a broader population is needed.^{[28][29][30][31]}

Rosmarinic acid (RA), which is found in lemon balm, has showed promise for Alzheimer’s disease (AD) in lab and animal studies, preventing amyloid β-protein from forming the fibrils that lead to the plaques and tangles characteristic of AD,^[5] but there isn’t much evidence that this will translate to people. An early randomized controlled trial (RCT) of hydroalcoholic lemon balm extract in 42 adults in Iran with mild to moderate AD found cognitive improvements over four months,^[9] although there was some risk of randomization and reporting bias in that trial. But more recent research hasn’t borne this out. A small 2020 RCT of lemon balm extract (providing 500 mg/day of RA) in 23 adults in Japan with mild dementia likely caused by AD found that, while lemon balm was safe and effective, there were no cognitive differences between the lemon balm and the placebo groups; the only significant difference was a reduction in the “irritation/lability” subscale on one test, which is in line with what we know about lemon balm’s calming effect.^[5] A follow-up RCT by the same researchers, of the same extract in the same dosage, in 323 adults without dementia but with subjective or mild cognitive impairment, failed to find any significant effect on cognition except in post-hoc subgroup analysis.^[6]

Lemon balm extract has also been studied for memory in young people without dementia, without conclusive results. Some lemon balm extracts have shown acetylcholine receptor activity in the lab, which is of potential interest both for cognition and for treatment of the cholinergic dysfunction seen in Alzheimer’s disease.^[8][7][60] A pair of pilot studies in the early 2000s tested the effects of lemon balm extract on a broad battery of cognition tests in young adults, with the second study focusing on an extract that showed cholinergic activity in the lab; the largest effect was a reduction in the speed of memory tasks after taking lemon balm (i.e., participants were slower to complete timed tasks), with a small improvement in accuracy for some doses and timepoints.^[8][7] Because of the large number of outcomes, the small number of participants, and the study design, these results are preliminary. Further, focused research would be needed to verify any positive effect of lemon balm extract on memory.

Although there’s not much evidence that lemon balm can help with memory, it might help with agitation in people with dementia when taken orally. A 2003 RCT of lemon balm extract for cognition in people with AD that recorded side effects noticed that the participants who were taking lemon balm experienced less agitation, although this wasn’t one of the study’s outcomes.^[9] And, as mentioned above, the 2020 Japanese RCT of lemon balm in people with AD noticed a reduction in irritation and lability.

Aromatherapy with lemon balm oil, diluted and applied to the skin, has also been evaluated for agitation in people with dementia, but the evidence so far is equivocal: One 2002 trial found that people with dementia who received lemon balm aromatherapy showed less agitation than those who received sunflower oil,^[38] but a similar 2011 trial found that there was no significant difference between lemon balm and sunflower oil.^[14]

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.^[2] 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.^[32] 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.

Lemon balm may benefit cardiovascular health by improving blood lipids: see FAQ:can-lemon-balm-reduce-cholesterol A 2020 meta-analysis of 6 studies found that lemon balm may also reduce systolic blood pressure (the first number in a blood pressure reading), but not diastolic blood pressure.^[32]

Although lemon balm has been recognized by the European Medicines Agency as a traditional herbal medicinal for digestion,^[21] there isn’t much human research into this use.^[41] Most studies have focused on lemon balm in combination with several other herbs. A 2019 in vitro study of lemon balm extract on mouse digestive system tissue (outside the mouse) found that lemon balm extract had a spasmolytic (muscle-relaxing) effect,^[41] which is in line with lemon balm’s traditional use as a digestive aid; however, much more research is needed into lemon balm’s effect on the human digestive system.

Maybe, although there is not much research in this area. One 2015 randomized clinical trial in 71 people in Iran with benign heart palpitations who took either a placebo or 1,000 mg of freeze-dried lemon balm extract for 14 days found that, in the 55 participants who completed the study, the participants who took lemon balm reported less-frequent palpitations than the participants who took the placebo. The number of participants in the lemon balm group with anxiety and insomnia also decreased more than in the placebo group.^[23] However, this was a single study; more research is needed.

There is very little human research, and it is not promising. A single 2016 randomized controlled trial in children with sleep bruxism (grinding teeth while asleep) didn’t find any effect after a month of lemon balm tincture.^[39]

There aren’t any clinical reports of drug interactions with lemon balm. However, it has the following theoretical drug interactions:^[40][43][42]

Additionally, there’s in vitro evidence that one component of lemon balm, rosmarinic acid, may inhibit some of the enzymes also used to process drugs: cytochrome P450 (CYP450) enzymes CYP2C19 and CYP2E1, and UDP-glucuronosyltransferases (UGTs) UGT1A1, UGT1A6, and UGT2B7. This could theoretically affect the metabolism of any prescription drugs processed by these enzymes, although there have been no reports of this to date.^[65][42]

No serious negative side effects (“adverse events”) have been reported with lemon balm supplementation to date, and no side effects have been reported when it has been taken for less than 8 weeks.^[42]

Allergic: Some hypersensitivity reactions, such as contact dermatitis, have been reported.^[40][42]

Ophthalmological: There are some anecdotal reports of an increase in intraocular pressure.^[40][42]

Cardiovascular: Although lemon balm is traditionally used to treat heart palpitations,^[23] one randomized controlled trial reported that some participants experienced palpitations as an adverse event during the study.^[40][42]

Neurological: In addition to lack of alertness, headaches, EEG changes, and sleep disturbances have been reported.^[40][12][42]

Hormonal: There is a theoretical concern that lemon balm could have an effect on thyroid hormones, which is supported by in vitro evidence, animal studies, and one case report of lemon balm being used as a part of a successful combination treatment in a patient with treatment-resistant Graves’ disease.^{[44][45][46][47][48]} For this reason, people with thyroid conditions might consider having their thyroid hormone levels checked when taking substantial doses of lemon balm.

Lemon balm is generally not considered to be potentially addictive or habit-forming, although there is one case report of an adult with anxiety who experienced restlessness, tremor, distractibility, and sweating when they stopped taking lemon balm.^[66]