Hydrastine is an alkaloid, one of the chief components of goldenseal (Hydrastis canadensis) which was discovered in 1851 by Alfred P. Durand. Goldenseal is unique from other hydrastine containing plants in that (-)-β- hydrastine is the only hydrastine isomer present, while the (+)-enantiomer is found in other hydrastine-containing plants. . While a number of therapeutic activities have been attributed to berberine, the pharmacological effects of hydrastine are less studied and its safety profile is poorly understood and to frame the relevant pharmacological effects of hydrastine within the specific stereochemistry found in goldenseal. Hydrastine has been shown to have several specific biological activities including, inhibition of tyrosine hydroxylase in PC-12 cells, a relaxant effect on guinea pig isolated trachea, and inhibition of several cytochrome P450 (CYP) enzymes. Toxicological studies performed on goldenseal powder in mice and rats indicate that at commonly used doses goldenseal supplements are non-toxic, thus its constituents are likely to be safe for human use when taken at reasonable doses. Despite goldenseal’s widespread usage, the pharmacokinetics of hydrastine in humans has not been adequately described. While it is difficult to determine the proper dosage range for any herbal product, a recent extensive survey of the literature suggests a daily dose of Hydrastis in the range of 0.9 to 3 g per day. Hydrastine has been reported to elicit abortifacient effects and induce preterm labor in pregnant women when taken orally.