Approved Injection Sites
Subcutaneous GLP-1 injections (semaglutide, tirzepatide, liraglutide) are approved for three site areas: the abdomen (at least 2 inches from the navel), the upper outer thigh, and the upper outer arm. All three sites offer access to subcutaneous fat tissue and are appropriate for 28-gauge or finer insulin pen needles or syringes. Intramuscular injection is not indicated — inject into the fat layer, not muscle.
Of these, the abdomen is the most commonly used because it's the most accessible for self-injection. The risk is that it becomes the only site — injected weekly, the same abdominal quadrant accumulates scar tissue (lipodystrophy) within months. This appears as firmness or lumpiness under the skin and causes inconsistent drug absorption. Systematic rotation prevents it.
Protocol's body map tracks every injection and shows when each zone was last used
Rotation Protocol
Use at minimum 4 distinct zones: abdomen left, abdomen right, left thigh, right thigh. Adding upper arm sites (left and right) gives you 6 zones — with weekly injections, each site recovers for 5 full weeks before reuse. This is the optimal rotation for preventing tissue changes on a once-weekly protocol.
Protocol's 3D body map tracks every injection to a specific zone and shows how long ago each was last used. The body map is available on iOS and Android — the only GLP-1 tracking app with this feature.
