Why does my GLP-1 injection hurt?

This is the most common fixable cause. The Ozempic and Wegovy instructions both say to let the injection site dry before injecting, and MedlinePlus says to let the skin air dry. Pushing a needle through wet alcohol is widely thought to carry some into the puncture, which stings. Wipe, then wait until the skin looks and feels completely dry. It takes seconds.

Skin that is already irritated hurts more when you add a needle. The Wegovy instructions say not to inject where skin is tender, bruised, red or hard, and to avoid scars and stretch marks. The Zepbound vial instructions add skin that is scaly, pitted, thickened or lumpy. If last week's site is still sore, choose a different area entirely.

Bracing for a shot is instinctive, and it firms up the tissue at the site. Many people find the injection hurts less when they sit in a comfortable position, let the area go soft, and breathe out slowly as the needle goes in. Injecting into the thigh while standing on that leg, or into the abdomen while sitting hunched forward, makes relaxing harder.

It can. A review of factors that influence injection pain lists the injection site among them, alongside needle features and the formulation. Some people find one of the approved areas consistently more comfortable than another. As long as you keep rotating, it is reasonable to favor the area that hurts least for you.

Less than people assume. The Zepbound and Mounjaro pen instructions say it is not necessary to warm the pen to room temperature. In a 2025 randomized crossover study of 44 people self-injecting from autoinjectors, warming to room temperature did not change average pain scores, although some individuals noticed a difference either way. The formulation mattered far more than the temperature.

If you feel a cold pen stings, you can take it out of the refrigerator a little before injecting, as long as you stay within your product's room-temperature storage rules. Never warm a pen or syringe with hot water, a microwave or any other heat source. Novo Nordisk's prefilled syringe instructions specifically prohibit it.

Devices differ, so follow the one you have. Single-dose autoinjector pens go flat against the skin: the Zepbound pen's clear base sits flat on the skin before you unlock it. The Wegovy single-dose pen is different, because it only starts when pressed firmly, and its troubleshooting section suggests a firmer site, such as the thigh or upper arm, or standing up for an abdominal injection, if you have trouble. The Ozempic prefilled syringe uses a pinched fold of skin and a 45-degree angle. Using one device's technique on another is a common source of discomfort.

Yes, a needle that shifts in the skin during delivery is uncomfortable. Hold the device steady for the full time your instructions give, then lift straight away from the skin. Rocking the pen, lifting it early or twisting it on the way out all add to soreness.

Yes. The Ozempic and Wegovy FlexTouch instructions say to always use a new needle for each injection, to reduce the risk of contamination, infection, leaking medicine and blocked needles that lead to the wrong dose. The Zepbound KwikPen instructions say the same, to help prevent infections and blocked needles, and tell you not to store the pen with a needle attached.

The evidence is mixed. A small 2005 study of insulin pen needles found no increase in pain over a few reuses, while a 2026 review of pen needle reuse lists pain among its complications, along with tissue changes. Either way, the reasons the instructions give for a fresh needle are infection, leakage and blocked needles that deliver the wrong dose. Those are reason enough on their own.

A few things differ. The needle that goes into your skin has first been pushed through the vial's rubber stopper, and some people find that injection stings more. How much a single pass dulls a fine needle has not been well measured. Your technique also depends on the syringe your provider chose. The Zepbound vial instructions say your healthcare provider should tell you whether to pinch the skin, and to use a new syringe and needle for every injection.

If vial injections consistently hurt, ask your pharmacist or prescriber whether a different syringe or needle, or a different presentation of your medication, would suit you better. Do not improvise with needles or technique that your instructions do not describe.