Parkinson, born in 1567, spent his early life in Yorkshire. He moved to London at the age of 14 years to become an apprentice apothecary. Rising through the ranks, he eventually achieved the position of apothecary to James I, and a founding member of the Worshipful Society of Apothecaries in December 1617; until 1622 he also served on the Court of Assistants, the Society's governing body. In addition, he assisted the Society in obtaining a grant of arms and in preparing a list of all medicines that should be stocked by an apothecary. He was on the committee that published their "Pharmacopœia Londinensis" ("London Pharmacopœia") in 1618.