Oddly enough, venom evolution is one of the most productive areas of medical research.
For example, Brazil has an enormous number of vipers, and annually a lot of snake bites. Finally someone noticed that the victims all experienced a significant, but not usually harmful drop in blood pressure. Once they isolated the responsible molecule in the venom, and synthesized it, they developed an entirely new class of high blood pressure medicines.
Other good venoms: Deathstalker scorpion venom against brain cancer; honey bee venom against cancer and some neuro-muscular diseases; tarantula venom for Muscular Dystrophy; Brazilian yellow scorpion venom which causes pancreatitis, which is showing the molecular action of how other diseases cause it; cobra venom for arthritis.
Saw-scaled viper venom against one of the most lethal forms of heart attack; Gila monster venom to treat Type 2 diabetes; vampire bat saliva against stroke; and, right now, sea anemone venom in treating autoimmune disease.
Scientists have only thoroughly evaluated some 1,000 types of venom from the estimated 100,000 known types of venomous animals in the world.
And of course, NOBODY has managed to characterize mother-in-law venom...