Ephedrine is a naturally occurring substance that occurs in plants of the genus seaweed. It exhibits sympathomimetic properties. It is still sometimes used to treat hypotension and against narcolepsy. In the past, ephedrine was used more widely, for example as an asthma drug, as a rhinitis remedy (decongestion of the nasal mucosa) and in ophthalmology. However, due to newer, more selective drugs, it is not as commonly prescribed today. Due to its structural similarity to the narcotic drug methamphetamine (crystal meth), the distribution of ephedrine is strictly regulated. This makes potential abuse more difficult.