In common with these compounds, phenylethanolamine has strong cardiovascular activity[1] and, under the name Apophedrin, has been used as a drug to produce topical vasoconstriction.

The amino-group makes this compound a weak base, capable of reacting with acids to form salts.

Early, classical pharmacological studies of phenylethanolamine were carried out by Tainter, who observed its effects after administering it to rabbits, cats and dogs.

Doses of 1–5 mg/kg, intravenously, caused no definite changes in respiration in cats or rabbits, and additional experiments showed that phenylethanolamine had no broncho-dilatory properties in animals.

In vivo and in vitro experiments involving cat and rabbit intestinal smooth muscle showed that the drug produced relaxation and inhibition.

A detailed examination of the mydriatic effect of phenylethanolamine led Tainter to conclude that this drug acted by direct stimulation of the radial dilator muscle in the eye.

[15] Research by Carpéné and co-workers showed that phenylethanolamine[16] did not significantly stimulate lipolysis in cultured adipocytes ("fat cells") from guinea pig or human.

Moderate stimulation (intrinsic activities about half that of the reference standard, isoprenaline) was observed in adipocytes from rat or hamster.

[20] The two enantiomers of phenylethanolamine were studied for their interaction with the human trace amine associated receptor (TAAR1) by a research group at Eli Lilly.