This is what i found
Medications and medical devices
The Food and Drug Administration (FDA) prohibits the importation, by mail or in person, of fraudulent prescription and non-prescription drugs and medical devices. These include unorthodox "cures" for such medical conditions as cancer, AIDS, multiple sclerosis or arthritis, to name just a few. The FDA also prohibits the importation of drugs that haven't been approved for use in the United States. Even if these drugs and devices are legal elsewhere, if the FDA has not approved them for use in the United States, they may not be brought in, not even under a foreign doctor's prescription or an American doctor's supervision. They may not legally enter the United States and can be confiscated should they arrive by mail. You may, however, order FDA-approved medications for which you have a valid prescription. Generally speaking, you should not order more than a three-month's supply, and a copy of your prescription should be included in the package. Customs cautions you that Internet sales of pharmaceuticals from other countries that largely trade in medicines may not be admissible into the United States. You might want to check with the Food and Drug Administration to determine admissibility before you purchase any medications over the Internet.
It sounds like you can order shit like clomid, t3, proviron, etc as long as you have a valid prescription. But how customs know whether you have one or not? Do they actually check?