What is the history diet pills, tablets used as medicines?

When did people started using tablets and pills as medicines?
When did people started using diet pills?

The history of "diet" pills would fill a large book. Over 99% 0f them are quackery pills. Phenylpropanolamine helped temporarily. There are a few others that help, but only temporarily. Then all the weight is regained. The best is Dexedrine and some of the illegal recreational and habituating drugs.The very best is will power which can be motivated by severely restricting the liberties of overweight people and making life costly …like increased airfares, increase in driver’’s license fees, etc.