I'm one of those cantankerous individuals who, unless I find myself in serious trouble, won't put man-made chemicals into my body
High blood pressure is correlated with a greater risk of serious trouble. Since you're concerned about chemicals, may I suggest you consider speaking to a medical professional or clinical dietician about reducing added, refined Sodium Chloride (salt), added refined C12H22O11 (sugars), as well as C8H10N4O2 (caffeine). Possibly add some "natural" food, eg a glass of beetroot juice, which is proven to significantly reduce blood pressure:
Drinking beetroot juice reduces high blood pressure, trial shows Medical News Today
While drugs may work like a charm and require little effort, there are various other ways to reduce blood pressure (I've tried with some success).