Ask Dr. Lo: semaglutide

How does semaglutide work? What makes it safer than its prescription weight loss predecessors?

In the past, the most effective weight loss drugs were amphetamine-based diet pills (“speed,” phentermine and others).

As you would expect, they dramatically suppressed appetite and gave people a very energetic, euphoric effect. But almost nobody keeps weight off after taking those drugs, and they shouldn’t be used long term due to addiction and other health risks.

Fenfluramine was another weight loss drug often combined with phentermine (fen-phen). It was withdrawn from the market after heart risks were discovered.

Semaglutide is a GLP-1, unrelated to all other weight loss medicines. The first GLP-1 was approved in 2008 for diabetes, so that family of drugs has been around for more than 15 years with no new long-term side effects uncovered during that time.

Unlike those old-fashioned diet pills, semaglutide slows down food absorption, making you feel full longer. When you absorb calories more slowly, your body has a better chance to use those calories as energy, rather than being forced to store them as fat.

Semaglutide has recently been shown to reduce appetite by suppressing the food reward center in the brain.

In my 30 year experience treating overweight patients, semaglutide is the most effective AND lowest risk weight loss medicine I have ever prescribed.