I forget the exact statistic, but it's like a spoonful of botulism toxin can kill millions of people. It really is potent.
But the difference between poison/toxin and medicine is often just dosage. There are myriad, countless medicines to discover in toxins. The toxin of an animal for instance a snake, is not one toxin, it's hundreds, each with individual action.
There is a reason the ancient greek symbol for medicine has two snakes on it. Anyway here's an old article on it in case anyone is interested.
*This is not the article I originally read as that was easily ten years prior but search engines and enshitified and have decided this is the closest they will give me.