It's still a great big experiment, performed on people without informed consent.
By definition, a drug that has been through extensive clinical trials, the results of which were used to convince the FDA that the drug is safe and effective enough to grant regulatory approval is not “experimental.”
The only way you can get an experimental drug is if you volunteer to participate in a clinical trial. If you volunteer, you will be briefed as to the purpose of the drug and the risks and benefits of participating in the trial. You will then sign a consent form that stipulates that you have the right to withdraw from the trial at any time.
If you have not consented to participate in a clinical trial, then any drug you receive is FDA approved. This is a matter of federal law.