Quick answer

Lemon balm is a lemon-scented herb taken as tea or extract. In small studies, some single doses between 300 and 1,600 mg raised self-rated calm for a few hours, and 400 mg a day of one extract gave better sleep scores in two short trials. Both findings are graded early, and it is generally well tolerated.^1,2,3,4,5

Key facts

The two placebo-controlled sleep trials both used the same branded extract, so their results may not carry over to teas or other products.^3,4
Rosmarinic acid from lemon balm peaks in the blood about an hour after a dose on an empty stomach.⁶
Older adults took a lemon balm extract daily for 96 weeks in one trial, with no differences from placebo in vital signs or physical measures.⁷
NIH's liver injury database reports no link between lemon balm extracts and liver harm.⁸

What lemon balm is

Lemon balm is a flowering perennial native to the eastern Mediterranean and western Asia, now grown widely.⁸

Lemon balm contains rosmarinic acid and other polyphenols, and a lemon-scented essential oil with citronellal, neral and geranial.⁵

In laboratory work, compounds in one lemon balm extract slowed the breakdown of GABA, a calming messenger in the brain. This is a proposed explanation for its effects, not something measured in people.⁹

FDA lists lemon balm as generally recognized as safe as a food flavoring.⁵

NIH's complementary health center publishes fact sheets on many herbs, but not on lemon balm. Most of what is known comes from small trials and from NIH's liver and lactation databases.^5,8,10

What the evidence shows

Both claims below are graded early: a handful of small, short trials, two of them with authors tied to the company behind the product tested. The amount studied sits beside each claim.^4,11

May increase feelings of calm for a few hours after a single dose*^1,2,11,12

Early evidence

Three small crossover trials from one UK group gave healthy young adults single doses and tracked mood for up to 6 hours. Self-rated calmness rose after 300 mg of one extract and after 1,600 mg of dried leaf, and 600 mg lessened the drop in mood caused by a stressful multitasking test in 18 people. Some doses slowed memory tasks or lowered alertness. In a larger 2026 trial of 106 stressed young adults, 300 mg did not change overall calmness, the main outcome, though calm returned faster after demanding tasks.

Amount studied: Single doses of 300 to 1,600 mg, depending on the product

May improve self-rated sleep quality, in short trials of one extract*^3,4,9

Early evidence

Two randomized trials tested the same phospholipid-bound extract at 400 mg a day. In 100 adults with poor sleep or moderate stress, three weeks lowered scores on a standard sleep quality questionnaire much more than placebo, but the lemon balm group started with worse sleep. In a crossover trial of 30 adults, 400 mg taken 30 minutes before bed for two weeks lowered a sleep difficulty score by 2.9 points more than placebo; its lead author directs the company that sells the product. An earlier 15-day open trial of 600 mg a day of another extract had no placebo group.

Amount studied: 400 mg a day of a phospholipid-bound extract for two to three weeks

In a 96-week trial in older adults with memory concerns, the extract did not change memory and thinking scores compared with placebo.⁷

The single-dose studies also show why dose matters. The same group found calm rising at one dose, alertness falling at another, and memory tasks slowing at others, depending on the product.^1,2

How much people take

Mood and attention studies gave single doses of 300 to 1,600 mg, depending on the product.^1,2,11,12

The two placebo-controlled sleep trials used 400 mg a day of a phospholipid-bound extract, either as 200 mg twice a day or as 400 mg in the evening.^3,4

There is no official recommended amount, and we found no trial of lemon balm tea on its own. The dosage guide lists every amount studied, from single doses to a 96-week course.

Leaf, tea and extracts

Lemon balm products are made from the leaves. Different preparations of the same plant can act differently: in one study, a dried leaf product had effects that an earlier extract did not.^2,8

Both placebo-controlled sleep trials used one branded extract bound to phospholipids, made for better absorption. Results from it may not apply to other lemon balm products.^3,4

Our Sleep formula's label says its lemon balm extract comes from the stem, leaves and flower. The studies above used leaf preparations.^2,8

What's in ours

What’s in ours

Sleep: Lemon Balm Extract, 100 mg per serving, from the label

Our Sleep formula contains 100 mg of lemon balm extract per serving. The sleep trials used 400 mg a day of a different, phospholipid-bound extract, so we make no lemon balm claim for it.^3,4

Side effects and who should ask first

Lemon balm is generally well tolerated. Nausea, vomiting, stomach pain, dizziness and wheezing have been reported occasionally.⁵

In single-dose studies, the highest dose of one extract lowered alertness for several hours, and some doses slowed timed memory tasks.^1,2

In a three-week trial, mild stomach upset was about as common with lemon balm (4 of 52 people) as with placebo (5 of 48).³

No upper limit has been set for lemon balm. Studies have used single doses of up to 1,600 mg, and an extract providing 500 mg of rosmarinic acid a day for 96 weeks.^2,7

In test tube studies, freeze-dried lemon balm extract blocked thyroid stimulating hormone (TSH) from binding to human thyroid cell membranes. We found no study testing whether this happens in people taking a supplement.¹³

No official source we could find names a specific medicine that interacts with lemon balm. That is not proof of safety. Because some doses lowered alertness, ask before combining it with sedatives or sleep medicines, and ask first if you have a thyroid condition.^1,13

Ask first if you are pregnant or breastfeeding. Nothing is known about lemon balm passing into breast milk⁵
Ask first if you take thyroid medicine, sedatives, sleep medicines or any prescription medicine
Ask first before giving it to anyone under 18
Do not drive or use machinery if it makes you drowsy¹

Questions people ask

Does lemon balm tea work like the extracts in studies?

Not necessarily. The trials used capsules of specific extracts or dried leaf, and different preparations of the same plant can act differently. We found no trial of plain lemon balm tea.^2,3

Is lemon balm safe to take every day?

Daily use has been studied for up to 96 weeks in older adults taking an extract providing 500 mg of rosmarinic acid, with no differences from placebo in vital signs or physical measures. It is generally well tolerated, but ask first if you are pregnant, breastfeeding, or take thyroid medicine or sedatives.^5,7

Does lemon balm help with focus or memory?

The results do not agree. A single 1,600 mg dose raised memory scores in 20 young adults, other doses slowed memory tasks, and a 96-week trial in older adults found no change in memory and thinking scores.^1,2,7

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Sources

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.