The biggest concern of using online pharmacies is, of course, health. Some people who use online pharmacies do not take the time to get diagnosed by a doctor or other health care professional they simply decide on their own what is causing their symptoms. They often use the wrong drug to treat their symptoms, which can lead to some serious consequences. It's also impossible to tell how a new drug will affect you or will interact with other medications, adding another level of risk to ordering from online pharmacies without first consulting a professional. Likewise, many online pharmacies do not properly warn users of side effects or give precise guidelines for taking the medication.

Many online pharmacies do not sell dangerous prescription drugs, which mean even if they do interact with other medications, they are usually not that dangerous. However, the government does warn that any prescription medication can lead to health risks, so online pharmacies should be used with caution.

Another concern many governments and health professionals have with online pharmacies is that international online pharmacies may use a different formula for some medications, replacing specific ingredients with generics or other materials. This means that even if your doctor has prescribed a certain medication, the medication you get from these overseas pharmacies may not be the same. It will most likely not be harmful, but it may not provide the same level of benefits.

Health agencies are also very concerned about counterfeit medication. Some online pharmacies have actually sold either medication that they created themselves or medication that was expired. If the pharmacy is based in the United States or Canada, the risk of this is fairly low since fake pharmacies set up in these countries are usually quickly shut down. However, if you purchase medication from pharmacies in Mexico or abroad, there's a chance the pharmacy may be out to scam you. There is a thriving black market for medication that is near or past its expiration date, and many online pharmacies try to sell these expired medications because they can make a huge profit on them. Some also sell counterfeit medications that are often nothing more than sugar pills. However, customers may pay hundreds for these.

Despite these warnings, there are many legitimate online pharmacies out there, and health agencies do recognize many of them as real pharmacies. However, you do have to examine the online pharmacy before you buy from it just to make certain you're not about to get scammed or end up with medication that either doesn't work or is expired. Check with a health care professional if it appears that you have purchased medication that is counterfeit or is not exactly what the online pharmacy promised. Remember, it's better to be safe than sorry.