Lemon balm (Melissa officinalis) is somewhat unique in botanical health support. First, while many botanicals can take weeks or months to provide benefits, lemon balm can oftentimes provide an almost immediate effect. Secondly, lemon balm is considered a "biphasic" herb—meaning it can have different effects at different doses. For example, lemon balm has been shown to support both sleep and cognition. Sleep, cognitive support, stress relief At higher doses, and/or when combined with other calming herbs, lemon balm is a potent natural sleep aid. In this "sleep support" capacity lemon balm works primarily by enhancing the activity of GABA (gamma-aminobutyric acid), an inhibitory neurotransmitter. By increasing GABA levels, it lowers neuronal excitability, which is precisely why it helps the user wind down and drift off to sleep. But in it's other "cognitive" capacity, lemon balm improves cognitive function. This may seem counter-intuitive at first glance, but it's primarily due to the dose. At more moderate or targeted doses, the herb has been shown to modulate the hypothalamic–pituitary–adrenocortical axis. This modulation helps regulate cortisol—the body's primary "stress" hormone. By keeping stress levels in check, it prevents the cognitive "clouding" that happens when the human body is overwhelmed or fatigued. This is where the cognitive improvement comes from. At the same time this "cortisol modulation" effect (again, at the lower dose) also provides relief from feelings of anxiety and stress. *New study All of this was demonstrated in a new study, published in Therapeutic Advances in Psychopharmacology in February 2026. To conduct the study, researchers recruited 106 healthy young adults who reported experiencing moderate stress. The study subjects were then administered either a placebo or a single dose of a branded lemon balm product. The study subjects were then assessed at multiple points during the day—following a set of demanding cognitive tests. The researchers found that at five hours post-consumption, study subjects demonstrated better performance on the most demanding cognitive challenges compared to placebo. Why the smaller dose doesn't "put you to sleep" The core finding of the recent study is that cognitive performance and "calmness" are not actually opposites; for many people, they are partners. When you are under stress or experiencing cognitive overload (such as during a long workday), your brain often enters a "fight or flight" mode that impairs executive function. The researchers found that the lemon balm helped participants maintain a "calm but focused" state. By reducing the friction caused by stress, the brain was able to perform better on complex tasks. It isn't that the herb acts as a stimulant (like caffeine); rather, it acts as a buffer that clears away the "noise" of stress—allowing natural cognitive capacity to function at peak. The caveat The researchers noted that while the current study demonstrated cognitive performance support that lasted for at least five hours, it is a challenging area of research due to differences in doses and individual metabolism. In fact, the researchers documented different previous studies that reported different results. Some studies documented better executive function at three hours and six hours post-intervention, while others documented a decline in cognitive function. All of this highlights that lemon balm has great cognitive potential in a world experiencing sleep, stress and anxiety epidemics; however, it comes with an important caveat: taking too much can diminish the benefit. Consumers would be wise to rely on a proven, effective product with an appropriate dose, such as Optimal Calm from Optimal Health Systems. Click the banner ad on this page to learn more. - - - Sources: Therapeutic Advances in Psychopharmacology, Wikipedia (GABA).
