Table 1.

Summary of herbal and supplements for improving sleep

Herbal/natural supplement	Key compounds	Proposed mechanisms of action	Evidence of efficacy	Safety considerations
Valerian	Valerenic acid, isovaleric acid, sesquiterpenes	Modulation of GABA receptors, serotonin receptors	Improved sleep quality and reduced sleep latency in several RCTs and meta-analyses	Generally well-tolerated; may interact with sedative medications
Hops	Alpha-acids (humulones), beta-acids (lupulones), essential oils	Modulation of GABA receptors, serotonin receptors, melatonin receptors	Improved sleep quality and reduced sleep latency when used in combination with valerian	Few reported adverse effects; may interact with sedative medications and alcohol
Kava	Kavalactones	Modulation of GABA receptors, dopamine, serotonin, and glutamate neurotransmitter systems	Reduced anxiety symptoms and improved sleep quality in several RCTs	Concerns about hepatotoxicity, particularly with non-aqueous extracts; may interact with sedative medications
German Chamomile	Flavonoids (apigenin, luteolin), terpenoids (bisabolol, chamazulene), coumarins	Modulation of GABA receptors, anxiolytic effects through serotonin and dopamine receptors	Limited clinical evidence; some studies show improved sleep quality in older adult and postmenopausal women	Generally well-tolerated; may cause allergic reactions in individuals sensitive to plants in the Asteraceae family
Cherry	Melatonin	Regulation of sleep-wake cycles	Improved sleep quality and duration in a small RCT	Well-tolerated; no significant adverse effects reported
Tryptophan	Tryptophan (amino acid)	Precursor for serotonin and melatonin synthesis	Small improvements in sleep latency and total sleep time in a meta-analysis	Generally safe; may cause mild side effects such as nausea and dizziness
Theanine	l-Theanine (amino acid)	Modulation of neurotransmitter systems involved in sleep regulation	Improved sleep quality and duration when used in combination with GABA in a small RCT	Well-tolerated; no significant adverse effects reported
Melatonin	Melatonin (hormone)	Regulation of sleep-wake cycles	Reduced sleep latency and increased total sleep time in individuals with primary insomnia in a meta-analysis	Generally safe for short-term use; long-term safety data lacking
Magnesium	Magnesium (mineral)	Involved in sleep regulation; deficiency associated with sleep disturbances	Improved sleep quality and reduced insomnia severity in older adults with insomnia in a small RCT	Well-tolerated; may cause gastrointestinal side effects at high doses
Zinc	Zinc (mineral)	Involved in neurotransmitter synthesis and sleep regulation; deficiency linked to sleep disturbances	Improved sleep quality and reduced insomnia severity in nurses with rotating night shifts in a small RCT	Generally safe at recommended doses; excessive intake may cause copper deficiency and other adverse effects

GABA, gamma-aminobutyric acid; RCT, randomized controlled trial