GLP-1 Injection Site Rotation Planner
Pick your available injection sites, choose your injection frequency, and get a rolling 12-week calendar showing exactly where to inject each time. The planner warns you if any site would be reused too soon, and lets you log each injection so you can track your history. Nothing uploaded.
Next Injection
12-Week Rotation Calendar
Injection Log
Learn more: GLP-1 injection site rotation
Why rotation prevents lipodystrophy and ensures consistent dosing
Each injection punctures skin and tissue, damaging fat cells and causing a mild inflammatory response. If you inject into the same small area repeatedly, the tissue hardens and develops lumps - a condition called lipodystrophy. This scarred tissue absorbs medication unevenly and slowly, which can lead to inconsistent blood levels and reduced drug effectiveness. Common clinical guidance for injectable medications recommends waiting at least 28 days before reusing any single site - this calculator uses that 28-day cooldown as its default. Proper rotation across multiple sites in the abdomen, thighs, and upper arms distributes the damage, heals cleanly, and ensures that each 0.25mg, 0.5mg, 1mg or 2mg injection absorbs predictably and consistently.
How the rotation schedule uses cooldown warnings to keep you safe
The planner generates a rolling 12-week injection schedule that automatically cycles through your chosen sites in order, respecting the 28-day cooldown period between uses of the same site. If you select only 2 sites and inject weekly, the calculator warns you that you'd reuse a site after just 14 days - not enough time. A warning threshold shows you the minimum number of sites needed for your injection frequency: weekly injections need at least 5 sites (35 days total rotation = 5 weeks per site before reuse); every-two-weeks needs 3. Log each actual injection date to track your real pattern and get accurate cooldown alerts.
FAQ
Why is the 28-day cooldown important for injection sites?
Each injection damages tissue microscopically, and the site needs time to heal and redistribute the medication evenly. Reusing a site too soon (within 28 days) causes lipodystrophy - hardened lumps and scar tissue that reduce drug absorption. This means a 1mg injection into a lumpy site may absorb as if you'd only injected 0.7mg. Proper rotation ensures consistent absorption and prevents painful, disfiguring tissue damage over months of therapy.
How many sites do I need to rotate through?
For once-weekly dosing, you need at least 4-5 sites. For once-every-two-weeks, you need at least 2-3 sites. The minimum sites = ceiling(injection frequency in days / 7 / 28 days cooldown) + 1. For example, weekly injections need 5 sites (7 × 5 = 35 days to cycle through all sites, giving each 28 days rest). If you have fewer sites than needed, you'll reuse sites too soon and risk lipodystrophy.
Should I rotate within the same site area or move between body areas?
Yes, rotate both ways. First, rotate between the large body areas (abdomen, thigh, upper arm) - this gives each area a longer rest. Then, within each area, rotate to a different injection site (at least 1-2 fingers' width away from the previous spot). This approach distributes the cumulative damage across your whole body and reduces the risk of lipodystrophy in any one spot. Moving between large areas gives 4-6 weeks of rest per area.