许多药物都是经过反复试验后才被发现的。

Many drugs were found by trial and error.

《柯林斯英汉双解大词典》

许多药物可能不起作用，或者可能有危险的副作用。

Many of them may not work or may have side effects that can be dangerous.

youdao

许多药物原本都是来自于植物。

Many of our medicines originate in plants.

youdao

Many people in this room are currently suffering from a mood disorder, an anxiety disorder or both, and I won't ask for a show of hands but I know a lot of people in this room are on some form of medication for this disorder.

这个教室中的许多人,都正在遭受心境障碍,焦虑障碍,或是同时受到两者的困扰,我不会让你们举手示意,但是我知道,这里的许多人都正在使用药物,治疗这些心理障碍

耶鲁公开课 - 心理学导论课程节选