The most common side effects of GLP-1 agonists tend to be gastrointestinal problems including nausea, diarrhea, vomiting, and constipation. These side effects tend to be mild to moderate in severity and transient, and tend to occur within the first 5 months of treatment during the dose-escalation phase. More serious side effects, while rare, include diabetic retinopathy, thyroid cancer, gallbladder-related events, kidney injury, hypoglycemia, and pancreas-related events, all of which have been reported in clinical trials.[1]
The GLP-1 receptor agonists are also associated with an elevation in resting heart rate by 1–4 beats per minute.[1] Physician and podcast host Peter Attia has reported that his clinic has observed an overnight heart rate elevation of 8–10 beats per minute in his patients, although this is an anecdotal report and not peer-reviewed research.[2]