Drugs are tested using computer models and human cells in a lab
Animal testing: animals are given a known dosage of the drug to monitor for side effects
Volunteers and people: the drug is tested on healthy volunteers first to check safety at a low dosage and find any side effects. Then tested on people with the illness to see if they are safe and effective
Licensing: after passing all tests, drug companies get approval to produce more of the drug. This process can take 10-15 years as scientists need to look for any severe side effects