Until recently, the stomach was a “dead zone” for GLP-1s because stomach acid and digestive enzymes break down peptides before the body can absorb all of them. New oral GLP-1s are designed to protect peptides, the active ingredients in these medications, so they can survive the trip through your digestive tract.
The FDA approved the 25 mg pills for weight management because of how similar they were to injections in terms of weight loss and safety, says W. Timothy Garvey, MD, a professor of medicine at the University of Alabama at Birmingham.
Why does it take a 25 mg daily pill to do the same job as a 2.4 mg weekly injection? The higher dose ensures enough of the drug survives the trip through your system to be effective. The actual effect of the medication is nearly the same.
“The absorption of the oral med from the [gastrointestinal] tract into the bloodstream is poor, such that the amount of medication entering the bloodstream is similar for the oral and injectable,” Dr. Garvey says.