Belviq And Qsymia: Comparison Of New Weight Loss Drugs

The Federal Drug Administration has now approved 2 new weight loss drugs — Belviq and Qsymia — which are available only be prescription. These two drugs are designed for the same purpose, although they are actually very different. So, what should you know about two and is either one right for you?


According to Qsymia manufacturer, Vivus, the drug should be available sometime in the 4th quarter of 2012. Still, the drug can only be distributed through certified pharmacies as women taking Qsymia must take birth control as well. Qsymia will probably be available in the later part of the year through large pharmacies online.

Belviq, on the other hand, must be scheduled by the Drug Enforcement Administration because there is a potential for abuse. Because this process can take up to 6 months, Belviq will probably be available to consumers sometime in the early part of 2013, although a speedier DEA ruling is possible.

Why were both drugs approved after previous denials?

For a long time, obesity was considered an issue of vanity instead of a real health issue. Now that research is showing the true risks obesity causes, from diabetes to depression, it is becoming accepted as a disease. Both weight loss drugs were turned down only two years ago over concerns of serious heart risks for patients. Until recently, the FDA was hesitant to approve weight loss drugs because of the risks they carry, although viewing them as a treatment for a real disease has opened the window for both Qsymia and Belviq.

How the Drugs Work

Qsymia and Belviq work in very different ways to accomplish weight loss. Qsymia is a combination of two drugs. The first is an appetite suppressant called phentermine, which is considered the safer “phen” part of the now banned fen-phen. It’s believed that phentermine supresses your appetite by releasing norepinephrine in the brain, which increases the appetite-regulating hormone called leptin. The other drug in Qsymia is topiramate, which is used to treat seizures and migraines. This drug aids in weight loss by increasing the body’s ability to burn calories, making you feel fuller and making the taste of food less appealing. Qsymia is scheduled as a controlled substance due to the phentermine aspect of its makeup.
Belviq, on the other hand, is a single drug that aids in weight loss by activating a receptor that increases serotonin in the brain. Because only small doses are used for weight loss, Belviq does not activate the serotonin switches that cause hallucinogens and other effects. Still, high doses of Belviq can trigger the switches, so the drug must be scheduled as a controlled substance by the DEA.

Who are these drugs intended for?

Both Qsymia and Belviq are approved to treat patients with a BMI of 30 or higher, or those with a BMI of 27 or higher with at least 1 weight-related condition present, such as type 2 diabetes.
Both drugs should not be taken by pregnant women. Qsymia in particular has known risks during pregnancy, as it can cause oral clefts and other defects during the first trimester, even during the first week of pregnancy before a woman has a positive pregnancy test. Qsymia must be taken with a reliable birth control to prevent pregnancy.
Qysmia should be avoided by pregnant women, those with glaucoma and hyperthyroidism, those taking a MAOI antidepressant and those allergic to either topiramate or phentermine, the 2 components of the drug.
Belviq should be avoided by those who take drugs already linked to valvular heart disease as well as pregnant women. Those who should exercise caution while taking Belviq include: men with a deformed penis, me with conditions that cause long-lasting erections and people who take specific medications for thought and psychotic disorders, a cold, mood disorders, migraines and depression.

Which is more effective?

There is still no way to tell which drug is more effective for weight loss. While you can consider the results of the clinical trials that led to approval by the FDA, keep in mind this is no way to compare the effectiveness of both drugs because the clinical trials were set up in different ways. Those taking Belviq lost 3% to 3.7% more weight than the group on the placebo, while those taking Qsymia lost 8.9% more weight than the group on the placebo after taking the drug for 12 months.

How long are the two drugs taken?

Both Belviq and Qsymia are designed to be taken indefinitely as long as patients do not develop side effects or fail to achieve weight loss, at which point they should be discontinued.
It’s also important to note that both are intended to be used along with proper diet and exercise to be effective.