Mint Family (Lamiaceae)
Lemon balm’s Latin name comes from Melissa, a nymph in Greek mythology who shared wisdom of the bees (De la Foret n.d.). It is renowned for its calming effect on the nervous system, its gentle fever supporting action, and antiviral properties specific to herpes viruses. Lemon balm has an uplifting vibe to it, different from chamomile, though both soothe and calm nerves.
Like its mint-family relatives, lavender and rosemary, smelling lemon balm almost immediately has effects on most people’s nervous systems, and both inhalation and ingestion have some anxiety-relieving and pain-relieving properties.
Anxiety, depression, mood
A systematic review of studies of the effects of lemon balm on anxiety and depression found that it significantly improved mean anxiety and depression scores compared to the placebo (Ghazizade et al., 2021). Limitations were variation between the studies and the small number of clinical trials among the studies, and most did not use placebo controls.
In one of the few double-blind, placebo-controlled, randomised studies, lemon balm demonstrated improvements on mood and cognition after laboratory induced stress (Kennedy et al., 2004). In this study of healthy volunteers, participants were given two different doses of lemon balm extract and a placebo, with a 7-day clearout period in between, and subjected to a 20-minute psychological stressor to induce stress on the treatment days. The Defined Intensity Stressor Simulation (DISS) Computerized Battery entailed mathematical processing, visual monitoring, auditory monitoring, and memory search tasks presented via a split screen. Lemon balm at a 600mg dose was found to ameliorate the adverse impact on mood triggered by the stressor simulation and increased self-ratings of calmness and alertness; the lower 300mg increased mathematical processing speed (Kennedy et al. 2004).
As would be expected of an herb that alleviates anxiety, lemon balm can also promote better sleep.
One open-label (not blinded) 15-day study assessed the impact of a standardised lemon balm extract on 20 volunteer participants with mild to moderate levels of anxiety and sleep impairment. Each volunteer took 600mg of lemon balm extract daily, divided into two doses, and were interviewed using a test based on standard evaluations for anxiety and depression. The results showed significant improvements in anxiety symptoms and insomnia, with 70% achieving full remission of anxiety; 85% achieving full remission of insomnia; and 70% achieving full remission of both. However, this was a pilot study that was conducted without a placebo control, so placebo effect cannot be ruled out.
Traditionally, lemon balm has been used to alleviate pains, such as pain associated with digestive distress, menstrual pain, and headaches. Animal model studies of pain have shown that lemon balm extract causes dose-related antinoniception, or reduced sensitivity to pain caused by external factors (Bounihi et al. 2013). This indicates that it may also be useful in pain caused by injury to the body, in addition to its traditional use for digestive or menstrual distress.
Menstrual pain / Potentially other spasm pain
In a double-blinded study of college students with menstrual pain, 100 volunteer participants were assigned to either receive a placebo pill or a pill with 330 mg extract of herb (Mirabi et al., 2017). Both groups took the pill for three days from the beginning of menstruation three times daily over two cycles. The findings showed that the lemon balm group had significantly less pain severity than the control group in each cycle. In addition, after the second cycle, the duration of pain was significantly less in the lemon balm group than the control group (Mirabi et al., 2017).
Because menstrual cramps are caused by contractions of the smooth muscle of the uterus, it’s likely that lemon balm’s action on spasms is how it soothes digestive cramping, and points to potential relief with other kinds of cramping/spasms.
Digestive / Colic pain
Traditionally, lemon balm has been used to soothe stomach cramping, and other cramping as mentioned above.
A recent study shows that it may even help alleviate colic pain in babies when breastfeeding mothers consume it. A single-blinded study on infantile colic was done to assess impact on pain during one week of treatment with lemon balm extract - participants receiving the treatment were unaware of what they were receiving (Naderi Dastjerdi et al., 2019). 110 breastfeeding mothers with moderate to severe postpartum pain were assigned to receive either a capsule containing 395g of lemon balm extract or 250 mg mefenamic acid, a pharmaceutical pain reliever, every six hours for 24 hours following childbirth. Pain was assessed using a numeric 10-point scale before and at set intervals after each dose was taken.
The results showed that pain intensity did not significantly vary during the first two hours after the first dose, but there was a significant difference between the two groups in the third hour. The severity was also significantly different between the two groups at the assessment points an hour after the second, third, and fourth dose (Naderi Dastjerdi et al., 2019). This study did not use a placebo group receiving a control substance, so it’s unknown if the benefit stems from the placebo effect on the mother that could have been transmitted to the baby.
Lemon balm is known to fight various herpes viruses. In one of the few double-blind, placebo-controlled trials on 115 patients, a standardised lemon balm cream was tested for the treatment of cold sores, or herpes simplex labialis (Wolbling and Leonhardt, 1994). Patients with cold sores lasting no more than 72 hours prior to joining the intervention were given either a lemon balm cream or placebo cream. The results showed that lemon balm treatment reduced the size of the lesions and redness faster than the placebo (Wolbling and Leonhardt, 1994).
Numerous in vitro studies have found that lemon balm extracts result in herpes simplex virus type 1 virus death at low concentrations and reduce the cytopathic effects of herpes simplex virus type 2 on healthy cells (Miraj and Kiani, 2017).
In an in vitro study, various extracts of lemon balm were tested on various cancer cell lines, but in vivo studies are needed in order to confirm these effects. The 96% ethanolic extract was found to be the strongest chemoprotective agent - which protects against side effects of certain anti-cancer drugs - on the breast cancer cell line (Ghiulai et al., 2020). It had an antiproliferative effect - suppressing cell growth - and caused cell death in the colon cancer cell line (Weidner et al., 2015), and an antitumour effect - preventing growth of tumours - on three tumour cell lines (Magalhães et al., 2018).
Another study explored the effect of lemon balm infusion on oxidative stress status in radiology staff exposed to persistent low-dose radiation at work (Zeraatpishe et al., 2011). This was a clinical trial in which 55 staff drank an infusion of 1.5g/100mL twice daily for 30 days. Blood plasma was tested for markers of oxidative stress before and after, and it was found that the infusion intervention improved plasma levels of several markers of stress and in plasma DNA damage (Zeraatpishe et al., 2011).
Lemon balm is very safe.