Quick answer: Retatrutide has no FDA-approved label; its injection-site study used the thigh, upper arm and abdomen. Once a week across 4 areas (left and right abdomen, left and right thigh), each spot comes round again every 4 weeks. Enter your own start date, days and areas above to get your dated plan.
How the planner builds your rotation
The planner lists the areas you tick in a fixed order (abdomen left and right, then thighs, then upper arms) and repeats that list for as many injections as you plan. It puts each injection on the next day you inject, starting on the first of your injection days on or after your start date. If you have already started rotating, choose the last spot you used and the plan picks up from the next one.
With one spot per area, the two rotation orders give the same plan. With two or more spots per area, New area each injection moves to a different area every time and uses the next spot when it returns, while Finish one area, then move uses every spot in one area, one injection each, before moving to the next area. Either way, every spot is used once before any spot repeats, so the number of days before the same spot comes back is the same; only how often you return to the same area changes.
How often each spot comes back (once a week)
| Areas | 1 spot each | 2 spots each | 3 spots each | 4 spots each |
|---|---|---|---|---|
| 2 | 2 weeks (14 days) | 4 weeks (28 days) | 6 weeks (42 days) | 8 weeks (56 days) |
| 4 | 4 weeks (28 days) | 8 weeks (56 days) | 12 weeks (84 days) | 16 weeks (112 days) |
| 6 | 6 weeks (42 days) | 12 weeks (84 days) | 18 weeks (126 days) | 24 weeks (168 days) |
Weeks between two injections at the same spot: the number of spots in the rotation (areas times spots per area), one injection a week. These are counts, not a recommended rest period. If you inject more than once a week, the planner works out the days for your own schedule.
What this planner does not do
It does not choose your sites, tell you which area is best, or set your dose or dosing days. It lays out the areas and days you enter. It cannot see your skin: if a spot is sore, bruised or damaged on the day, use the "Last spot you used" box to restart the plan from wherever you injected. Retatrutide has no FDA-approved label or instructions for use. Always consult a licensed healthcare provider. See the retatrutide injection sites guide for how to inject at each area.
Frequently asked questions
Where can you inject reta?
Retatrutide is investigational and has no FDA-approved label or instructions for use. Lilly's injection-site study (NCT05959096) gave it under the skin of the thigh, upper arm or abdomen (the study record: "LY3437943 administered subcutaneously (SC) in either thigh, upper arm, or abdomen"). The Zepbound (tirzepatide) and Wegovy (semaglutide) labels name the same three areas (sections 2.4 and 2.1). This planner rotates through whichever of those areas you choose.
How do you rotate reta injection sites?
There is no FDA-approved retatrutide label to set a rotation rule. The Zepbound and Wegovy labels both say "Rotate injection sites with each dose" (sections 2.4 and 2.1). Enter your start date, injection day and the areas you use, and the planner gives a site for every injection date, cycling through every spot before it repeats one.
Can you inject reta into your own upper arm?
Retatrutide has no FDA-approved label or instructions for use. For comparison, the label of Zepbound (tirzepatide, also made by Lilly) says "another person should inject in the back of the upper arm" (section 2.4). The planner leaves the upper arm unticked until you add it.
How long before the planner brings me back to the same spot?
It depends on how many areas and spots you rotate through and how often you inject. Once a week across 4 areas with one spot each, the same spot comes back every 4 weeks (28 days); keeping 2 spots in each area doubles that to 8 weeks. The planner shows the exact number of days for your own schedule. These are counts, not a recommended rest period.
Safety: Retatrutide is an investigational compound and is not approved by the FDA. This tool is educational only. It lays out the sites you choose on the dates you enter; it does not recommend an injection site, a dose or a dosing schedule. Always consult a licensed healthcare provider about your treatment.