Injection-Site Rotation Map

Tap a site each time you inject there. Every marker recolors by how long it has rested, and the longest-rested site is recommended next, so the same tissue is not used twice in a row.

Front view of a body; tappable markers sit over the common subcutaneous injection sites on the upper arms, abdomen, and front thighs

Tap any marked site to log an injection there today. The number on each marker is the days since it was last used.

Suggested next site …
Recency
  • Rested, ready (at or past cooldown)
  • Nearly ready
  • Recovering
  • Just used, avoid

How long tissue should rest before a site is "ready" again.

Injection-site rotation reference

Why rotate injection sites

Repeated subcutaneous injections into the same patch of tissue are the main cause of lipohypertrophy, the rubbery, thickened lumps of fat and scar tissue that build up at overused sites. Beyond being visible and uncomfortable, injecting into lipohypertrophic tissue changes how the drug is absorbed, making the effect erratic. Systematic rotation, leaving each site enough time to recover before it is used again, is the standard prevention, and the reason structured rotation is recommended for insulin and other repeated subcutaneous injections.

How the map works

The figure shows the common subcutaneous self-injection zones on the front and back of the body: the upper arms, the abdomen (kept clear of the area right around the navel), the flanks and upper buttocks, and the thighs. The anterior and posterior arm and thigh are different tissue, so they count as separate sites in the rotation, sixteen in all. Each time you inject, tap that site; the tool records today's date, resets that site's clock to zero, and recolors it.

What the colors mean

Every marker is shaded by how many whole days have passed since it was last used, and the number on each marker is that day count. Green means the site is at or past your recovery window and ready; blue means it is nearly there; amber means it is still recovering; red means it was just used and should be avoided. Because the meaning is also written in each marker's number and label, the map does not rely on color alone.

Why about 14 days

The default recovery window is 14 days, a commonly cited rest period for a subcutaneous site to recover before reuse. It is adjustable between 7 and 21 days to match your own protocol and the density of your rotation. The suggested next site is always the eligible site that has rested the longest; if no site has cleared the window yet, the tool falls back to the best-rested one and warns you that the rotation may be too small or too fast.

Cadence and cycle length

The cadence note does the simple arithmetic of how often your schedule returns to any one site: the number of sites in the rotation times the days between injections. If that cycle is shorter than the recovery window, the tool warns you, because it means tissue is being reused before it has fully rested. Adding sites or spacing injections further apart lengthens the cycle.

Data handling and privacy

Everything is computed and stored in your browser using local storage; nothing is sent to a server as you use the map. A reload restores your colored map exactly. Export your history as JSON or CSV for a backup, or build a share link to move it to another device. Creating a share link is the only action that sends anything off your device: the rotation state is saved under a short code so the link stays compact, and it happens only when you click Share.

Scope & safety

PepRecon is a research and education resource. This tool tracks where you have injected; it is not medical advice and does not establish a dosing or technique recommendation. Standard subcutaneous zones are shown for reference only; the safe sites and technique for your situation should come from a qualified clinician.

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