GLP-1 Advisor | One Day MD

Updated September 2026 GLP-1-based medicines have changed the treatment of obesity by making substantial, sustained weight loss possible for many people. But as the scale goes down, an important question follows: How much of the weight being lost is fat, and how much is lean tissue? This matters because long-term health is not determined by body weight alone. Preserving skeletal muscle, strength, physical function and nutritional adequacy is particularly important during substantial weight loss. The good news is that current evidence does not support the idea that GLP-1 therapies simply “eat away” muscle. Most weight lost with semaglutide and tirzepatide is fat mass. At the same time, measurable reductions in lean mass can occur, particularly during large or rapid weight loss. The most defensible strategy is therefore not to avoid effective obesity treatment, but to improve the quality of weight loss with adequate protein, progressive re...

By Dr. Frank Yap, MD · One Day Media Network · Last updated October 20, 2026 · Part of the GLP-1 Resource Hub Quick Answer This A–Z directory defines 53 GLP-1 and peptide terms, from adverse events and AOD-9604 to Zepbound. Each entry gives a plain-language summary, a CEBM evidence level and regulatory status, with links to our in-depth guides. As of October 2026, GLP-1 drugs such as semaglutide and tirzepatide are FDA-approved with strong trial evidence, while most “wellness” peptides (BPC-157, TB-500, KPV, MOTS-c, Semax, epitalon) remain unapproved and not yet legal to compound. Medical disclaimer: This directory is educational and is not medical advice. Do not start, stop or change any prescription or peptide without a licensed clinician. Affiliate disclosure: some pages in our network contain affiliate links (for example The Wellness Company and Amazon Associate...