Whilst GLP-1 RA usage is effective at driving weight loss, the magnitude varies depending on factors such as the type of GLP-1 RA used, treatment duration, and the individual
Contributor Hope Ricciotti, MD, Editor at Large, Harvard Women's Health Watch Disclaimer: As a service to our readers, Harvard Health Publishing provides access to our library of archived content
Black and tarry stools may also occur due to: Abnormal blood vessels in the esophagus, stomach, or duodenum A tear in the esophagus from violent vomiting (Mallory-Weiss tear) Blood supply being cut off to part of the intestines Inflammation of the stomach lining (gastritis) Trauma or foreign body Widened, overgrown veins (called varices) in the esophagus and stomach, commonly caused by liver cirrhosis Cancer of the esophagus, stomach, duodenum, or ampulla of Vater When to Contact a Medical Professional Contact your health care provider right away if: You notice blood or changes in the color of your stool You vomit blood You feel dizzy or lightheaded In children, a small amount of blood in the stool is most often not serious

Dosing in the Phase 3 Diabetes Trial (TRANSCEND-T2D-1) A1C reduction: -1.7% to -2.0% across doses (from baseline 7-9.5%) Weight loss at 12 mg: 16.8% (-36.6 lbs) at 40 weeks Discontinuation due to adverse events was relatively low across all doses, similar to the patterns seen in TRIUMPH-4 The diabetes population typically loses less weight on GLP-1 drugs than the obesity-only population, which is consistent with what was observed: ~17% weight loss in T2D vs
Common areas include the calves, thighs, feet, hands, or back
The weight loss trajectory with retatrutide is steeper and more prolonged than those reported for tirzepatide and semaglutide in cross-trial comparisons