(4R)-1,2,3,4-Tetrahydro-2-methyl-4,8-isoquinolinediol Hydrochloride Hydrate is an impurity of Phenylephrine (P320635), a selective α1-adrenergic receptor agonist used as a decongestant. Phenylephrine lowers intraocular pressure and is used as an agent to dilate the pupil.
