Lemon balm – The versatile "bee herb" for nerves, stomach and more

Lemon balm (Melissa officinalis) is one of the longest-used plants in European herbal tradition. Its calming effect on nervousness and sleep difficulties is officially recognised, its antiviral activity against herpes simplex viruses well documented – and current research is exploring its possible role in cognitive health in older age. A factual look at the evidence.

Where lemon balm comes from and what its leaves contain

Lemon balm originates in the eastern Mediterranean and western Asia and reached Central Europe through monastic medicine – it is already listed among the crops to be cultivated in Charlemagne's Capitulare de villis (around 800 AD). Its characteristic lemon scent, which attracts bees and gave the plant its Latin name "Melissa" (Greek for honeybee), comes from a complex mix of plant compounds in the leaves.

The leaves used medicinally (Melissae folium) contain, among other compounds:

• Essential oil with the monoterpenes citral (geranial and neral) and citronellal – responsible for the characteristic scent
• Rosmarinic acid and caffeic acid, the main representatives of the Lamiaceae tannins
• Flavonoids with antioxidant properties
• Beta-caryophyllene as a further aromatic constituent

Preclinical research has shown that lemon balm extract inhibits the enzyme GABA transaminase, which breaks down the calming neurotransmitter GABA in the brain (Awad et al., 2007 and 2009, in vitro/animal studies). Slower GABA metabolism is considered one of several possible explanations for the calming effects observed in clinical studies. Research literature also discusses a binding affinity to GABA-A receptors and involvement of the serotonergic system (Kennedy et al., 2002 and 2003, human studies on acute effects on mood and cognitive performance); however, a single, fully established mechanism of action does not yet exist.

Historically, lemon balm was already used in ancient Greece and in Arabic and medieval European medicine for nervous complaints, digestive problems and sleep disturbances. This long tradition makes it one of the most thoroughly studied plants of European herbal medicine in modern clinical research.

How a 2023 study examined stress and sleep quality

A randomised, double-blind, placebo-controlled human study published in Frontiers in Pharmacology in 2023 (Bano et al., DOI: 10.3389/fphar.2023.1250560) investigated the effects of a standardised, phospholipid-based lemon balm extract in 100 healthy adults with moderate emotional stress or sleep problems.

Over three weeks, participants took 200 mg of the extract twice daily (400 mg per day). In the lemon balm group, depression, anxiety and stress scores on the DASS-42 scale decreased significantly more than under placebo (all p < 0.001). Sleep quality, measured using the Pittsburgh Sleep Quality Index (PSQI), also improved more markedly in the lemon balm group: the score fell on average from 10.9 to 3.5 points, compared with 8.6 to 6.6 points in the placebo group (group × time interaction p < 0.001; lower scores indicate better sleep quality). The supplement was well tolerated, and no serious adverse events occurred.

An important caveat: the study tested a specific phospholipid-based extract (phytosome carrier system) with enhanced bioavailability. The results cannot automatically be extended to all lemon balm extracts.

What laboratory studies show about antiviral activity against cold sores

The antiviral activity of lemon balm extract against herpes simplex virus (HSV-1) is among the best-studied properties of the plant. In vitro studies show that rosmarinic acid, one of the main active compounds, inhibits the attachment of herpes viruses to host cells – in both aciclovir-sensitive and aciclovir-resistant strains (Schnitzler, Navid & Astani, Phytotherapy Research 2014, in vitro study).

At the clinical level, a double-blind, placebo-controlled, randomised study compared a standardised lemon balm cream (1% dry extract) with placebo in 66 people with recurrent herpes labialis (Koytchev, Alken & Dundarov, Phytomedicine 1999, human RCT). On the second day of treatment, the lemon balm group showed a significantly lower symptom score than the placebo group.

A later, smaller study compared lemon balm gel directly with 5% aciclovir cream (Ahadian et al., Jundishapur Journal of Natural Pharmaceutical Products 2015, human RCT, n = 60). No significant difference was found between the two treatments in lesion size or healing time; pain intensity decreased even more with lemon balm gel than with aciclovir on days 2 and 4. However, the authors note that lemon balm gel was overall not superior to the established therapy. In several European countries, a standardised lemon balm leaf cream is approved as a topical medicine for the treatment of herpes labialis.

Why lemon balm leaves are officially recognised for nervousness and sleep difficulties

The German Commission E has officially recognised the use of lemon balm leaves for nervous sleeping difficulties and for functional gastrointestinal complaints. The European Scientific Cooperative on Phytotherapy (ESCOP) also lists lemon balm for nervousness, restlessness and irritability. For sleep difficulties and nervousness, lemon balm is often combined in herbal practice with other traditionally used plants such as passionflower, lavender or hawthorn.

On safety: caution is advised when taking lemon balm alongside sedatives, sleep medication or thyroid medication, as it may influence their effects; consulting a doctor is recommended (Ulbricht et al., 2005). Lemon balm tea in household amounts is considered safe; higher-dose extracts should only be used during pregnancy and breastfeeding after consulting a doctor.

What role lemon balm plays for digestive complaints

In preclinical research, lemon balm extracts have a relaxing effect on the smooth muscle of the gastrointestinal tract. Lemon balm leaves are a component of traditional herbal preparations for functional digestive complaints such as bloating and flatulence – an application also recognised by Commission E. In traditional European formulations, lemon balm is often combined for this purpose with other antispasmodic plants such as peppermint, caraway or fennel, for example in tea blends or stomach drops. The underlying mechanisms – modulation of smooth muscle and mild mucosa-protective effects – have been described in cell models and animal studies; larger placebo-controlled human studies on lemon balm alone for digestive complaints are still lacking, so this assessment relies mainly on traditional use and the Commission E approval.

What current research shows on lemon balm and cognitive health in older age

A young field of research is investigating the possible neuroprotective effect of lemon balm extract. Two smaller clinical studies are frequently cited:

In a double-blind, randomised, placebo-controlled study of 42 people with mild to moderate Alzheimer's disease, cognitive performance improved significantly more after four months of lemon balm extract than under placebo (ADAS-cog: p = 0.01; CDR: p < 0.0001) (Akhondzadeh et al., Journal of Neurology, Neurosurgery & Psychiatry 2003, human RCT). Agitation also occurred more frequently in the placebo group than in the lemon balm group.

A 24-week study of 23 people with mild Alzheimer's dementia tested an extract standardised to 500 mg of rosmarinic acid daily (Noguchi-Shinohara et al., Scientific Reports 2020, human RCT). No significant group difference was found on the cognitive test scores themselves; the total score of the Neuropsychiatric Inventory questionnaire (which captures behavioural and mood symptoms, among others) improved by an average of 0.5 points in the lemon balm group, while it worsened by 0.7 points in the placebo group (p = 0.012). The preparation was well tolerated, with no serious adverse events.

At the molecular level, it is discussed that rosmarinic acid affects the aggregation of beta-amyloid peptides and that lemon balm extract binds to cholinergic receptors in the brain. A narrative review published in the Asian Journal of Green Chemistry in 2026 summarises preclinical findings on Nrf2/ARE and NF-κB/MAPK signalling pathways (Yusupovna et al., 2026, narrative review, not a clinical study).

An important caveat: the clinical Alzheimer's studies available so far are small, short and partly contradictory – a larger study (Burns et al., 2011), for example, found no benefit of lemon balm oil aromatherapy over placebo for agitation. The evidence does not justify therapeutic claims, but it does point to a scientifically interesting avenue for further research.

A European plant combination for mental balance

Dosage forms and typical use at a glance

Form	Typical use	Area of application
Tea (dried leaves)	1–2 tsp per 150 ml hot water, steep 5–10 min, up to 3× daily	Digestion, mild nervousness
Extract / capsules	200–400 mg daily, depending on standardisation	Stress, sleep quality, general wellbeing
Tincture	2–3 ml, up to 3× daily	Nervousness, digestive complaints
Cream / gel (topical)	Several times daily on the affected area	Cold sores (available as an approved medicine)

What the evidence on lemon balm shows overall

Lemon balm is one of the most extensively studied plants of European herbal medicine, with a solid clinical basis for stress, sleep quality and topical use for cold sores. Research on cognitive health in older age is promising but still early and not yet sufficient to support specific recommendations. Anyone looking to support their nervous system and sleep with lemon balm will find standardised extracts – often combined with complementary plants – an approach that has been tested in several studies.

---

This article is intended for general information about lemon balm and does not replace medical advice, diagnosis or treatment. If you have health concerns, please consult a doctor or pharmacist.

---