Vervain is a genus of annual and perennial flowering plants with about 250 species in the family Verbenaceae. Vervain can be chopped and boiled with water to make tea. The tea has been used as a herbal remedy for sleep problems. Rodents studies have indicated that it does have sleep promoting qualities.

Vervain chemical composition
Vervain  is an herb that has a number of compounds, including tannins, flavonoids such as hispidulin, jaceosidin, apigenin, 4'-hydroxywogonin, verbenalin and hastatoside.

Cancer protection
Afr J Tradit Complement Altern Med. 2013. Study on in-vivo anti-tumor activity of Verbena officinalis extract. It has in vivo anti-tumor effect, while causing no damage on the immune function.

Vervain Research study
Hypnotic effects of total aqueous extracts of Vervain hastata in rats.
Psychiatry Clin Neurosci. 2002.
The in vivo sedative property of the total aqueous extract of the aerial portion of Vervain hastata (Verbenaceae) (TAEV) was studied in male rats to establish its scientific basis in herbal medicine. The investigation was conducted using electroencephalogram (EEG) analysis, and the barbituric-hypnosis test. The results showed that TAEV potentiated the pentobarbital-induced hypnosis significantly by reducing sleep latency and increased sleeping time in a dose-dependent manner that was reversed by flumazenil. The EEG data demonstrated that extract administration augmented total sleep time, rapid eye movement (REM) sleep and non-REM sleep at the expense of wakefulness. The study's results clearly showed the scientific validity for the use of this plant as a sedative and possibly as a nerve tonic substance.

 Analysis of vervain flavonoids by HPLC/Diode array detector method. Its application to quality control.
J Agric Food Chem. 1999.
A reversed-phase HPLC procedure is proposed for the determination of seven flavonoids (luteolin, nepetin, hispidulin, jaceosidin, cirsimaritin, cirsilineol, and eupatorin) in vervain samples. A simple extractive technique was developed, involving only extraction with ethyl ether, which allowed the elimination of phenolic acids, yielding a sufficiently purified flavonoid fraction. All of the analyzed vervain samples showed a common flavonoid pattern, in which hispidulin and jaceosidin were the major compounds and nepetin was the minor compound.

Blue Vervain is verbana hastata.