For most folks with diabetes, regular check-ups at the doctor’s office to help fine-tune insulin dosage, monitor blood sugar levels and catch potential complications are a must to stay on top of this metabolic disease. That’s why a growing number of health care professionals are growing worried over this fact: Some forms of insulin can actually be bought without a prescription in the United States, allowing some patients to self-medicate, Kaiser Health News and NPR report.

There are two types of human insulin available over the counter; Eli Lilly makes one and the other is produced by Novo Nordisk. These are older, less concentrated versions of insulin that take the body longer to metabolize. These versions of insulin are also far cheaper than the newer, prescription-only options.

The U.S. Food and Drug Administration (FDA) supports the OTC options. The FDA said insulin is a very safe drug, and that more availability would, ultimately, mean better safety for patients. In addition, non-prescription insulin might also be an effective, cheaper option for patients with diabetes who don’t have health insurance.

Still, many doctors said those benefits don’t outweigh the potential risks of taking insulin without proper training or monitoring by a health care professional. That’s because taking the wrong dose of insulin can eventually destroy the body. What’s more, poorly managed diabetes is linked to a host of other health issues, including high blood pressure, kidney disease, nerve damage, loss of eyesight and stroke.

“We clearly think the newer versions are more close to what the body would do on its own,” said Todd Hobbs MD, chief medical officer at Novo Nordisk, which produces one type of OTC insulin. He also agreed with doctors that prescription versions of insulin are safer because they make it easier for patients to avoid wild fluctuations in their blood sugar levels.

For tips on how to better control your blood sugar with diabetes, click here.