Injection site rotation
Last reviewed 2026-06-11 · 5 min read
Bottom line: injecting the same spot over and over irritates the tissue under it. Rotating across a handful of sites — and writing down which one you used — keeps skin and muscle healthy and absorption consistent.
Why rotation matters
Repeated injections into one spot can cause lipohypertrophy — a rubbery thickening of the fat layer that's been documented for decades in insulin users. Beyond the lump itself, scarred or thickened tissue absorbs drugs erratically, which quietly changes what a "stable" dose actually delivers. Rotation is the boring fix: give each site time to recover before it's used again.
Common subcutaneous sites
Subcutaneous (subq) injections go into the fat layer. The usual map:
- Abdomen — at least two finger-widths from the navel, left and right. The most common choice for GLP-1s and many peptides.
- Thighs — front-outer middle third, left and right.
- Back of the upper arms — the fatty area, left and right.
- Upper buttock / flank ("love handle") — left and right.
That's already an 8-spot rotation — with one injection a day you return to a site about once a week, which is plenty of recovery time.
Common intramuscular sites
Intramuscular (IM) injections — typical for testosterone esters — go deeper:
- Ventrogluteal (side of the hip) — large muscle, away from major nerves; widely taught as the preferred glute site.
- Vastus lateralis (outer thigh) — easy to self-inject, left and right.
- Deltoid — fine for small volumes (commonly ≤ 1 mL).
- Dorsogluteal (upper-outer buttock) — traditional, but requires care to stay in the safe quadrant.
What a rotation log looks like
A useful log answers two questions instantly: where did the last shot go, and which site has rested longest? On paper that's a column next to your dose log. In Stack it's a body map: every dose records its site, and the app recommends the least-recently-used one next — so "did I already pin the left side this week?" stops being a memory game. Get the app →
Soreness notes are data
If a site is unusually sore, red or warm afterwards, write that down too. A pattern at one site (but not others) is exactly the kind of signal a log surfaces and memory loses — and it's worth showing a clinician.