MINNEAPOLIS (WCCO) — Two new diet drugs are the first to be approved in more than a decade. Both Belviq and Qsymia helped people lose weight in clinical studies, but they do it in very different ways.

Qsymia will be available the fourth quarter of this year, and it looks like Belviq with be available first quarter of next year.

Qsymia combines an appetite suppressant and a medication for seizures and migranes. The drug is known to increase feelings of fullness, make foods taste less appealing and increase calorie burning.

Belviq causes weight loss by turning on a specific switch that increases levels of serotonin.

The drugs are not for everyone. They will only be prescribed to obese adults or overweight adults who have at least one additional health-related issue. Those include Type 2 Diabetes, high blood pressure, or high cholesterol.

There are risks associated with both drugs. Qsymia has particular risks for pregnancy. It can cause birth defects if taken in the first months of pregnancy, so women prescribed the drug must also be on birth control.

Pregnant or nursing women also cannot take Belviq.

At this point, there’s no way to know for sure which one works better. They haven’t been tested in a head-to-head clinical trial.

People taking Belviq had an average weight loss that was 3 to 3.7 percent greater than people taking placebo.

People taking Qsymia for up to one year had an average weight loss of 8.9 percent over those taking an inactive placebo.

However, these numbers cannot be used to compare the two drugs, as the clinical trials had different designs. Also, the drugs were effective only when given along with a balanced diet and exercise.