1. Mercury
For hundreds of years mercury was being used to treat numerous ailments comprising typhoid and syphilis.
2. Leeches
Leeches were used to get rid of “bad blood.” In 80’s they were used to save lives, reattach limbs, and make various transplants possible.
3. Meth
For the first time it was actually used on the battlefield to bring “wakefulness” in soldiers. Since then it is being used as a performance enhancer and weight loss remedy.