Lemon Balm (Melissa officinalis) is a popular herb from the mint family, frequently utilized for its calming properties. Its leaves, which release a distinct lemon scent, have been incorporated into traditional medicine for centuries. A common question concerns whether consuming lemon balm might act to increase the body’s estrogen levels. This article examines the scientific literature to clarify the herb’s known effects, particularly on the endocrine system, and its interaction with estrogen.
Traditional and Modern Applications
Lemon balm has a long history of use in folk medicine, primarily valued for its soothing influence on the nervous and digestive systems. It is consistently classified as a nervine herb, supporting its traditional use for conditions related to stress and agitation. Modern research supports its application in anxiety reduction, promoting a sense of calm without causing significant drowsiness at moderate doses.
The herb’s calming effects are largely attributed to its interaction with the brain’s gamma-aminobutyric acid (GABA) system. Compounds within the plant, notably rosmarinic acid, are thought to inhibit an enzyme called GABA transaminase. By slowing the breakdown of GABA, which is the main inhibitory neurotransmitter, lemon balm may increase its availability in the brain, contributing to its anxiety-reducing and sedative properties.
Beyond its psychological benefits, the herb is also frequently used to support sleep quality and aid in digestive comfort. Its volatile oils contain terpenes that are believed to contribute to its mild sedative and carminative (gas-relieving) effects. Some studies suggest that lemon balm can enhance memory and alertness under stressful conditions.
Investigating Lemon Balm’s Effect on Estrogen
The question of whether lemon balm increases estrogen levels is answered by examining its chemical composition and its activity at the cellular level. Estrogenic activity in plants is usually due to compounds known as phytoestrogens, which structurally mimic the human hormone estradiol and can bind to estrogen receptors. Lemon balm is not classified among the common phytoestrogen-rich herbs, such as soy or red clover, which contain isoflavones.
Scientific investigation has not found evidence that lemon balm directly acts as an estrogen agonist. In fact, some in vitro (test tube) studies hint at a potentially opposite effect in specific contexts. Certain extracts of Melissa officinalis have shown the ability to inhibit the growth of estrogen receptor-positive breast cancer cells (MCF7).
This anti-proliferative activity on estrogen-sensitive cells suggests that the herb’s compounds may exert an anti-estrogenic or neutral effect. This finding is from isolated cell studies and does not confirm a systemic effect in the human body, nor does it mean the herb is a treatment for cancer. There is currently a lack of clinical trial data demonstrating a measurable change in a person’s circulating serum estrogen levels following lemon balm consumption.
The herb is rich in phenolic compounds like rosmarinic acid and flavonoids, which are studied for their antioxidant and anti-inflammatory properties. While some flavonoids can interact with hormone pathways, the available scientific literature does not support the claim that lemon balm significantly increases estrogenic activity in humans. Its primary biological effects remain focused on the nervous system and the thyroid gland, not on the estrogen pathway.
Lemon Balm and Thyroid Function
While lemon balm does not appear to increase estrogen, it has a notable interaction with a different part of the endocrine system: the thyroid gland. This effect is medically significant and provides context for its overall hormonal profile. The herb contains phenolic acids, such as rosmarinic acid, which can interfere with the body’s thyroid hormone processes.
Extracts of Melissa officinalis have been shown to inhibit the binding of Thyroid Stimulating Hormone (TSH) to its receptors on thyroid cells. This molecular action can reduce the stimulatory signal that TSH sends to the thyroid gland, which may decrease the production of thyroid hormones like T4 (thyroxine).
This inhibitory action is why lemon balm has been studied for conditions involving an overactive thyroid, such as hyperthyroidism and Graves’ disease. In Graves’ disease, antibodies mistakenly mimic TSH, overstimulating the thyroid; lemon balm extracts have been shown in test tube studies to potentially block these autoantibodies from binding to the receptor.
For individuals with hyperthyroidism, this interference might be beneficial. However, for those with a normally functioning or underactive thyroid (hypothyroidism), consuming lemon balm could reduce thyroid hormone levels or interfere with the effectiveness of prescribed thyroid-replacement medications.
Safety Profile and Contraindications
Lemon balm is generally considered safe for most adults when consumed in common food amounts or used short-term in medicinal doses. Reported side effects are typically mild and may include minor symptoms like increased appetite, dizziness, nausea, or wheezing. The herb’s strong calming effects necessitate caution regarding its use alongside other sedating substances.
Combining lemon balm with prescription sedatives, sleep aids, or alcohol can result in excessive drowsiness or slowed breathing. Due to its sedative properties, individuals scheduled for surgery are advised to discontinue use at least two weeks beforehand.
The most significant contraindication relates to its interaction with the thyroid gland. People with any form of thyroid disease, particularly hypothyroidism, should avoid lemon balm because it may worsen the condition or counteract the effects of thyroid-replacement therapy. Furthermore, there is insufficient reliable data to confirm the safety of lemon balm during pregnancy or while breastfeeding, and professional guidance suggests avoiding its use during these times.