(+)-pilocarpine

Pilocarpine is a drug used to treat dry mouth and glaucoma. It is a parasympathomimetic alkaloid obtained from the leaves of tropical South American shrubs from the genus Pilocarpus. It is a non-selective muscarinic receptor agonist in the parasympathetic nervous system, which acts therapeutically at the muscarinic acetylcholine receptor M3 due to its topical application, e.g., in glaucoma and xerostomia.
It is on the World Health Organization's List of Essential Medicines, a list of the most important medication needed in a basic health system.