Drug discovery has the following stages.
The first one is in silico, this means that the scientific experiments or research is conducted or produced by means of computer modelling or computer simulation.
Then, the experiments or research becomes in vitro. This means that the process is performed or taking place in a test tube, culture dish, or elsewhere outside a living organism.
Subsequently, the process is performed or taking place in a living organism. This phase is called in vivo.
Lastly, clinical trials are made. These are research studies performed in people that are aimed at evaluating a medical, surgical, or behavioral intervention. They are the primary way that researchers find out if a new treatment, like a new drug or diet or medical device (for example, a pacemaker) is safe and effective in people.