Apigenin is a naturally occurring flavonoid found in various plants such as chamomile. Its use for supporting insomnia is primarily based on emerging scientific evidence rather than longstanding traditional use. Several preclinical studies have investigated the potential sedative and anxiolytic effects of apigenin. Mechanistically, apigenin is believed to bind to benzodiazepine receptors on the GABA_A receptor complex in the brain, which may contribute to its calming and sleep-promoting properties.

Animal studies show that apigenin can prolong sleep time and reduce the time needed to fall asleep, presumably by enhancing GABAergic neurotransmission. For instance, a study published in "Biochemical Pharmacology" (2000) demonstrated that apigenin exerts anxiolytic and mild sedative effects in mice without causing significant muscle relaxation or motor impairment. However, robust human clinical data are lacking. Only a few small studies, often involving chamomile extracts (which contain apigenin among other components), suggest potential benefits in improving sleep quality in humans, but these are not definitive and do not isolate apigenin as the sole active compound.

In summary, while early scientific evidence—mainly from animal and in vitro studies—suggests a plausible mechanism for apigenin’s sedative effects, the overall evidence supporting its use for insomnia is limited (rated 2/5). Larger, well-controlled human trials are needed to confirm its efficacy and safety as a treatment for insomnia.