Effexor (venlafaxine hydrochloride) is a structurally novel antidepressant for oral administration. It is chemically unrelated to tricyclic, tetracyclic, or other available antidepressant agents. It is designated (R/S)-1-(2-(dimethylamino)- 1-(4-methoxyphenyl)ethyl) cyclohexanol hydrochloride or (+)-1 -(a-((dimethyl-amino) methyl)-p-methoxybenzyl) cyclohexanol hydrochloride and has the empirical formula of C17H27NO2 HCI. Its molecular weight is 313.87.

Venlafaxine hydrochloride is a white to off-white crystalline solid with a solubility of 572 mg/mL in water (adjusted to ionic strength of 0.2 M with sodium chloride). Its octanol water (0.2 M sodium chloride) partition coefficient is 0.43. Compressed tablets contain venlafaxine hydrochloride equivalent to 25 mg, 37.5 mg. 50 mg, 75 mg, or 100 mg venlafaxine. Inactive ingredients consist of cellulose, iron oxides, lactose, magnesium stearate, and sodium starch glycolate.