Quote Originally Posted by Delta9
Dopamine injections into the cactus as it grows would increase it potency because dopamine is a biological precursor to the active component. Dopamine is a controlled substance as well however, but it is found in banana peel and is water soluble. In fact dopamine has been measured in banana peel at a value of up to 100mg dopamine/g of peel.

Save your banana peels in a big baggie in the freezer and when you got a huge bag full of frozen peel grind them up and simmer them in a huge pot with distilled water.
decoct them for a long time filter off the ground peel pulp and boil off most of the water. allow to cool and water/inject you cactus with the aqueous banana extract.

Humidity plays a role as well cactuses grown in humid environments are gennerally less potent than dry environments. Look for darker cactuses. Dark green are more potent than lighter colored cactuses.
Won't increase potency of the cactus! At best youy'd just be adding dopamine to your cactus. If you want to increase potency do a extraction and dose with mesc.