Example of drugs from plants are:

Aspirin, quinine, morphine and many more. However a large proportion of drugs made from plants are not medically used.

Drugs must be tested before given out to people to use. This is because they are substances that cause changes to the body. If they are not created correctly for the person, it could cause harm instead of help them. The first stage to testing a drug is with human cells grown in a laboratory to make sure it is not toxic to us, make sure it is safe. This first stage is very crucial as this is probably the first version of the drug and it may not be developed right. It is common for the substance to fail this first test. After the first stage the drugs are tested on animals. A specific amount is given and then the animal is monitored very carefully for more or less the whole time, looking for any effect to appear. If the drug passes the second stage it is tested on healthy human volunteers. They are given a miniscule amount to make sure that there are no problems. Finally an optimum dose of the drug is tested on them and they are monitored. There is always the possibility that the dose could have unexpected side effects that harm, causing the drug to undergo more development, costing more and more money.