The question of whether we should buy medicine over the internet is hotly debated, but it is important to clarify the type of product in question. Buying vitamins or Arthritis relief over the internet is a very different thing to buying a prescription drug.
There are many medicines that you absolutely should not buy over the internet. Prescription drugs are one of these. Firstly they have not been recommended to you by your doctor and secondly the type of company that would sell these medicines illegally over the internet might also not be so scrupulous when it comes to the content of the drug. You literally do not know what you are buying and you could become severely ill or die.
Likewise you should be very careful buying non-prescription drugs that you do not know the manufacturer or seller. Even if they are labelled as herbal, this does not necessarily mean that they are not harmful or do not have side effects.
But that is not to say that you cannot buy vitamins and other such items on the internet. There are many reputable companies who sell vitamins on-line. Avoid any companies who make miraculous claims on their site or who are not transparent in their contact details on their website.