Common side effects
GLP-1 and GLP/GIP medications slow gastric emptying and affect appetite signaling. The most common side effects are gastrointestinal: nausea, constipation, diarrhea, vomiting, reflux, burping, abdominal discomfort, and early fullness. Some people also report fatigue, headache, injection-site irritation, dehydration, or changes in food tolerance.
Why compounded products need extra caution
FDA-approved GLP-1 products typically use standardized pens or labeled products. Compounded GLP-1 products may be dispensed in multi-dose vials with syringes and unit-based instructions. That makes clear dosing instructions, provider education, and pharmacy quality controls especially important. Dosing errors can lead to excess exposure and more intense side effects.
Red flags
Seek medical guidance promptly for severe abdominal pain, persistent vomiting, signs of dehydration, fainting, possible allergic reaction, severe constipation, gallbladder-type pain, or if you think you injected the wrong amount. This page is educational and should not replace provider guidance.