Scopolamine (also known as Hyoscine) is an alkaloid obtained from plants of the Nightshade family (Solanaceae), mainly from henbane (Hyoscyamus niger). It can be found in a variety of non-prescription sedatives.

Structurally similar to the neurotransmitter acetylcholine, it acts by interfering with the transmission of nerve impulses by acetylcholine in the parasympathetic nervous system, and typical symptoms of exposure include dilated pupils, rapid heartbeat, and dry skin, mouth, and respiratory passages.

Because scopolamine depresses the central nervous system, it is used as a sedative prior to anesthesia, but can also be used to treat various disorders characterized by restlessness and agitation, such as delirium tremens, psychosis, manias, and Parkinson's disease.

Overdosage of scopolamine causes delirium, delusions, paralysis, and stupor, and it is rarely abused.