After studying at Aberdeen University and Hanau in Germany, he established himself at Riga as a merchant, and subsequently in the West Indies, where he acquired property.

[2] After "thirty-five years' inexpressible suffering", and experimenting with every imaginable course of medical treatment, he accomplished "his own extraordinary cure" about 1822 by the simple expedient of swallowing a few vegetable pills of his own compounding at bed-time and a glass of lemonade in the morning.

His success led him to set up in 1825 as the vendor of what he called "vegetable universal medicines", commonly known as "Morison's Pills", of which the principal ingredient was said to be gamboge.

His medicines soon became highly popular, especially in the west of England, and in 1828 he opened an establishment for their sale in Hamilton Place, New Road, London, which he dignified with the title of "The British College of Health".

[2] In 1836, his business received heavy criticism as an apothecary Robert Salmon was indicted for the manslaughter of John M'Kenzie by administering large quantities of Morison's pills.