Minoxidil, a trichogenic compound that stimulates the hair follicle, is a pro-drug converted to its active form, minoxidil sulfate, by sulfotransferase enzymes in the outer root sheath of hair. Minoxidil sulfate is required for both the promotion of hair regrowth and the vasodilatory effects of minoxidil. Minoxidil sulfate is an activator of the ATP-sensitive K+ (KATP) channel. The opening of K+ channels is thought to be an important mechanism in the regulation of hair follicles.

4-(M-Chlorophenylcarbamoyloxy)-2-butynyl)trimethylammonium (McN-A-343) is a selective muscarinic M1 receptors agonist, which leads to its widespread use as an aid to distinguish responses mediated through M₁ receptors from those utilizing M₂ or M₃ muscarinic receptor subtypes, especially in the CNS. McN-A-343 has a number of non-muscarinic actions. These include activation of some types of nicotinic acetylcholine receptors, antagonism of serotonin 5-HT₃ and 5-HT₄ receptor subtypes, inhibition of the uptake mechanism and a local anesthetic action.