a FLOWER – a (Tetrahydrocannabinolic Acid) is the precursor to product (Tetrahydrocannabinol), the psychoactive compound in cannabis. a is found in raw, unheated cannabis plants and does not produce psychoactive effects. When exposed to heat through processes like smoking or vaping, a decarboxylates into product, becoming psychoactive and producing the well-known “more” associated with cannabis consumption.