GLP-1s typically go in one of three places: the abdomen, the thigh, or the upper arm. Ozempic, Wegovy, Mounjaro and Zepbound all use the same three.
And it does not matter which one you pick. That has actually been tested: the official prescribing information for both semaglutide and tirzepatide says your body absorbs the same amount of drug from all three sites. There is no spot that works better, no site that makes your dose go further.
Which leaves the question worth answering: how do you rotate so the spot you use in March still works properly in September?
Quick reference: Ozempic, Wegovy, Mounjaro and Zepbound
| Ozempic / Wegovy (semaglutide) | Mounjaro / Zepbound (tirzepatide) | |
|---|---|---|
| Approved sites | Abdomen, thigh, upper arm | Abdomen, thigh, back of upper arm |
| Upper arm | ”Only with help from someone else" | "Another person should inject in the back of the upper arm” |
| Distance from navel | At least 2 inches | At least 2 inches |
| Rotation | Change the site with each injection; do not use the same site each time | Rotate injection sites with each dose |
| Same region, different spot | Use a different site each week when injecting in the same body region (Ozempic) | You may use the same area but choose a different injection site in it |
| Site vs exposure | Similar exposure across all three | Similar exposure across all three |
| With insulin or other injectables | Same body region allowed, not adjacent, never mixed (Ozempic) | Do not inject in the same injection site used for other medicines |
| Injection site reactions | Ozempic 0.2%; Wegovy 1.4% vs 1% placebo | 6% at 5 mg, 8% at 10 and 15 mg, vs 2% placebo |
The short version: the guidance is basically identical across all four. Same three sites, same two inches from the navel, rotate every dose, upper arm needs another person, and the site never changes how much drug you absorb.
One row is worth your attention, and it is the last one. Lumps and redness at the injection site are far more common on Zepbound and Mounjaro than on Ozempic and Wegovy: 6 to 8 percent depending on dose against 2 percent on placebo, and 11.3 percent in people who developed antibodies to the drug. Ozempic is 0.2 percent and Wegovy 1.4 percent. So if you switched from Ozempic to Zepbound and started getting more reactions, that is the drug, not your technique.
On Ozempic? Regimen’s Ozempic app logs the shot in one tap, reminds you before the next one, and ties your side effects and weight to each dose step.
The three sites in practice
Abdomen. The workhorse. Enough subcutaneous fat to pinch on most people, easy to see, and a large enough area that you can rotate around it for weeks without repeating. Stay on softer tissue, clear of the navel and any scars.
Thigh. Front and outer, roughly the middle third between hip and knee. Easy to reach sitting down. More likely to sting if you carry less fat there, though how much a site stings is individual.
Upper arm. The fleshy back of the arm, and the one site both manufacturers say needs another person. Worth adding to a rotation if you have help, because a fourth and fifth position meaningfully extends the recovery window for every other site.
Wondering what is normal? Ozempic side effects by dose has every rate from Novo’s label, including the three warnings most articles skip.
Why rotation matters more on a weekly drug
This is the part that GLP-1 guidance tends to understate.
If you inject daily, an overused spot announces itself. It gets sore, you move. On a weekly medication you can return to the same comfortable square of abdomen for months and never get a warning, because nothing hurts. Lipohypertrophy builds silently. The lumps are usually painless.
The consequence is not dramatic, which is also why it goes unnoticed: tissue that has thickened absorbs unpredictably. You do not get a clear failure, you get a slow drift into weeks that feel inconsistent for no obvious reason.
A four-site rotation gives every area about a month to recover:
| Week | Site |
|---|---|
| 1 | Left abdomen |
| 2 | Right thigh |
| 3 | Right abdomen |
| 4 | Left thigh |
With a helper for both arms, a six-week cycle stretches it further. Within a site, move the precise spot as well: “left abdomen” is a palm-sized area, not a single point.
Four weeks is exactly long enough to forget which thigh you used. Regimen keeps your rotation and names the next site when the dose is due.
Track your rotation freeNovo adds a detail specific to staying in one region: use a different injection site each week when injecting in the same body region. In other words, “abdomen every week” is fine as long as it is not the same square of abdomen every week.
What to avoid, on any GLP-1
- Skin that is bruised, tender, red, hardened, or scarred
- Any firm patch you can feel, which should come out of the rotation entirely for months
- The area within two inches of the navel, which both manufacturers specify, and directly over scars
- Muscle. These are subcutaneous drugs. If you are lean, pinch the skin and inject into the fold
If you use insulin as well, the two labels differ slightly and the stricter one is easy to follow: Novo allows the same body region as long as the injections are not adjacent, while Lilly says not to inject tirzepatide in the same injection site used for other medicines. Neither product is ever mixed in a syringe with anything else.
A little bleeding afterwards is normal. Press gently with gauze or cotton, and do not rub.
The habit problem, and how to solve it
Almost nobody stops rotating on purpose. They stop because four weeks later they genuinely cannot remember whether the last one went in the left thigh or the right.
Regimen records the site with every dose and shows it back as a body map, so the next spot is already chosen when you pick up the pen. It logs how each week went alongside it, so an overused area shows up as a pattern instead of a hunch. Free for one medication, no time limit and no card.
Get Regimen freeWhatever you use, the test is the same: in four weeks, will it still know where you injected?
What about retatrutide?
Retatrutide is not approved anywhere, so there is no prescribing information to quote and no manufacturer site data behind it. In practice people use the same subcutaneous sites, and often the glute as well, which no approved GLP-1 lists. We keep that separate rather than folding assumptions into a page about drugs that do have labels: see retatrutide injection sites.
Sources
Semaglutide site lists, rotation instructions, the two-inch clearance, the upper-arm qualifier, the insulin guidance, the bleeding instruction and the 0.2 percent Ozempic reaction rate come from Novo Nordisk’s Ozempic prescribing information and Instructions for Use, revised May 2026, and the Wegovy prescribing information. The tirzepatide site list, rotation instruction, exposure statement, co-injection rule and the 6 to 8 percent reaction rates come from Lilly’s Zepbound prescribing information and Instructions for Use. Both manufacturers specify at least two inches from the navel. Neither lists the glute.
This article is for tracking and education. It is not medical advice, and dosing or administration questions belong with your prescriber.
Frequently asked questions
Where do you inject GLP-1 medications?
All of them use the same three subcutaneous sites: the abdomen, the thigh, and the upper arm. That is true for Ozempic and Wegovy (semaglutide) and for Mounjaro and Zepbound (tirzepatide). Both manufacturers also qualify the upper arm the same way: Novo says only with help from someone else, and Lilly says another person should inject there.
Does the injection site affect how well a GLP-1 works?
No. Novo's label states that similar exposure is achieved with subcutaneous administration of semaglutide in the abdomen, thigh, or upper arm, and Lilly's label says the same for tirzepatide. Both manufacturers tested it and found no meaningful difference. Site choice is about comfort and long-term skin health, not about absorbing more drug.
Which GLP-1 injection site is least painful?
Comfort is individual and depends mostly on how much subcutaneous fat you have at each site, so it is worth trying all three rather than assuming. Separately from comfort, how often a site reacts differs by drug: Ozempic reports injection site reactions in 0.2 percent of patients and Wegovy in 1.4 percent, while Zepbound reports 6 to 8 percent depending on dose against 2 percent on placebo.
How often should you rotate GLP-1 injection sites?
Every injection. Novo's instruction is to change the injection site with each injection and not use the same site each time, and Lilly's is to rotate with each dose. On a weekly drug this is easy to neglect, which is exactly why lipohypertrophy develops on GLP-1s. A four-site rotation gives each area about a month to recover.
Can you inject a GLP-1 and insulin in the same area?
The two manufacturers differ slightly. Novo says for Ozempic that you may inject it and insulin in the same body region, such as the stomach, but not right next to each other, and never mixed in one syringe. Lilly is stricter for tirzepatide: do not mix Zepbound with any other medicine and do not inject it in the same injection site used for other medicines. Follow the stricter rule if you are unsure, and confirm the spacing with your prescriber.
Is the injection site different for Ozempic versus Mounjaro?
The sites are the same, and so is almost all the guidance: three sites, two inches from the navel, rotate every dose, upper arm with help. The meaningful difference is not the site but the reaction rate. Lilly reports injection site reactions in 6 to 8 percent of Zepbound patients depending on dose, against 2 percent on placebo, while Novo reports 0.2 percent for Ozempic and 1.4 percent for Wegovy.
What is lipohypertrophy and why does it matter on a GLP-1?
Lipohypertrophy is the firm, fatty thickening that builds up in tissue injected repeatedly in the same spot. It is usually painless, which is why people do not notice it forming. It matters because changed tissue absorbs unpredictably, so a site you have overused can quietly make your weeks less consistent. It is the main reason rotation is worth the small effort.
Can you inject a GLP-1 in the glute?
The glute is not listed in any of the four labels. It is a conventional site for some peptides, but for branded GLP-1 pens there is no absorption benefit to leaving the labelled sites, and no manufacturer data supporting it. Stay with the abdomen, thigh, and upper arm.
How far from the belly button should you inject?
At least two inches, and both manufacturers say so. Novo's Ozempic and Wegovy Instructions for Use say to inject into the stomach area at least 2 inches from the belly button, and Lilly says the same in the Zepbound KwikPen Instructions for Use and its patient guidance. The tissue right around the navel is tougher and more fibrous, so stay clear of it and of scars.
What should you do if the injection site bleeds?
Novo's patient instructions say that if blood appears at the injection site, press lightly with a gauze pad or cotton ball, and do not rub the area. A small amount of bleeding or a brief sting is normal. Redness, swelling or a lump that persists is worth mentioning to your prescriber, and that area should be left out of your rotation until it resolves.
Is there an app that tracks GLP-1 injection sites?
Yes. Regimen records the site with every weekly shot and shows it back as a body map, so the next spot is already chosen when you pick up the pen. On a once-weekly drug that is the difference between real rotation and using the same side of your stomach for a year without noticing. Free for one medication.
