1. The FDA cautions people to shun internet pharmacies that offer drastically lowered prices, don't require a prescription, or don't list a phone number. With any such sites, you run the risk of getting stuck with counterfeit, contaminated, or incorrect drugs, not to mention getting ripped off altogether. One of the oldest internet scams is for any old Joe to copy pictures from other sites, create a site in about half-an-hour, and offer a particular product at vastly discounted prices. Little do the customers now they're merely handing over a charge to their credit card to someone who has no intentions of ever delivering the product.
2. Try asking your insurance company if they have preferred online or mail-order partner pharmacies.
3. Use only legitimate operations approved by the National Association of Boards of Pharmacy. Their website is nabp.net.
4. Check out pharmacychecker.com for user comments and ratings of online pharmacies.