https://en.m.wikipedia.org/wiki/Parasympathomimetic_drug

vs

https://en.m.wikipedia.org/wiki/Insect_growth_regulator

..

https://en.m.wikipedia.org/wiki/Parasympathomimetic_drug

Pharmaceuticals Supplements
Direct-Acting

These act by stimulating the nicotinic or muscarinic receptors.

Choline Esters:

Acetylcholine
(all acetylcholine receptors)

Bethanechol
(M3 receptors)

Carbachol
(all muscarinic receptors and some nicotinic receptors)

Methacholine
(all muscarinic receptors)

Plant alkaloids:

Arecoline
Nicotine
Muscarine
Pilocarpine (M3 receptors)