Salsolinol is a tetrahydroisoquinoline derived from dopamine which plays a role in neurotransmission and is a dopaminergic neurotoxin.

It has been linked to dopamine-related disorders including Parkinson's disease and alcohol use disorder. It is both synthesized in the human body and ingested in several common dietary sources.

Salsolinol is a catechol isoquinoline which is a yellow solid at room temperature. Salsolinol, as a chiral molecule, comes in two enantiomers: (R)-salsolinol and (S)-salsolinol. The two may have different biological effects.

The racemate can be synthesized via a Pictet-Spengler reaction. A chemoenzymatic, enantioselective synthesis of the (R)-enantiomer has also been reported. Salsolinol has been used as a starting material to prepare some tetrahydroisoquinoline-based prospective drugs.

Salsolinol is found in several edible plants, most prominently bananas and cocoa products as well as beer. Other plants, including black cohosh, which is used in many herbal remedies, also contain salsolinol.

Salsolinol is endogenously synthesized by multiple routes, although its origin in the human body remains controversial. There are two main routes for its production: one which is through a non-enantiospecific Pictet-Spengler reaction of dopamine and acetaldehyde, and one which is mediated by the enzyme salsolinol synthase.

Salsolinol synthase exclusively produces the (R)-enantiomer of salsolinol.

It has been speculated that salsolinol may also arise from salsolinol-1-carboxylic acid, which is formed by the reaction of dopamine and pyruvic acid. This transformation would occur via a proposed enzymatic pathway that has not been elucidated yet.