Side effects of the newest GLP-1

As of 2026, beyond the well-known GI effects (nausea, constipation, reflux), emerging real-world concerns with newer GLP-1 and dual/triple agonists include excess lean mass loss during rapid weight reduction, possible bone density decline if resistance training is absent, gallbladder disease, rare but serious pancreatitis, delayed gastric emptying severe enough to affect anesthesia safety, and small increases in resting heart rate. There are also increasing patient reports of libido changes and mood variability, though data are still evolving. Most of these aren’t “hidden,” but they’re under-emphasized because they’re uncommon, patient-specific, or still being clarified in long-term outcome studies.