A short history of medicine

I have a headache:

2000 BC: Here, eat this root. 1000 AD: That root is heathen. Here, say this prayer. 1850 AD: That prayer is superstition. Here, drink this potion. 1940 AD: That potion is snake oil. Here, swallow this pill. 1985 AD: That pill is ineffective. Here, take this antibiotic. 2015 AD: That antibiotic is artificial. Here, eat this root.

(Adapted from post originally published here).