Insomnia is a common sleep disorder which is prevalent in women and the elderly. Current insomnia drugs
mainly target the γ-aminobutyric acid (GABA) receptor, melatonin receptor, histamine receptor, orexin, and serotonin
receptor. GABAA receptor modulators are ordinarily used to manage insomnia, but they are known to affect sleep
maintenance, including residual effects, tolerance, and dependence. In an effort to discover new drugs that relieve
insomnia symptoms while avoiding side effects, numerous studies focusing on the neurotransmitter GABA and herbal
medicines have been conducted. Traditional herbal medicines, such as Piper methysticum and the seed of Zizyphus jujuba
Mill var. spinosa, have been widely reported to improve sleep and other mental disorders. These herbal medicines have
been applied for many years in folk medicine, and extracts of these medicines have been used to study their
pharmacological actions and mechanisms. Although effective and relatively safe, natural plant products have some side
effects, such as hepatotoxicity and skin reactions effects of Piper methysticum. In addition, there are insufficient evidences
to certify the safety of most traditional herbal medicine. In this review, we provide an overview of the current state of
knowledge regarding a variety of natural plant products that are commonly used to treat insomnia to facilitate future
Hypnotic, insomnia, natural products, sedatives, γ-aminobutyric acid.
State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Xian Nong Tan Street, Beijing 100050, P.R. China.