What we’ll cover

• What are injection site reactions?
• How common are they?
• Simple steps to ease discomfort
• When to reach out for clinical support

How common are they?

Injection site reactions are classed as a common side effect. This is defined as affecting between 1 in 100 and 1 in 10 people. What does that mean in a way that makes more sense? Essentially, whilst not everyone will get an injection site reaction, they’re not unusual either.

Tips to reduce the risk of injection site reactions

During your injection: 

• Rotate your injection site: Switch between your stomach, thigh or upper arm to avoid using the same area repeatedly.

After your injection:

• Apply a cold compress: A damp cloth or wrapped ice pack can soothe the area and reduce itching or swelling.
• Avoiding irritants: Using gentle, fragrance-free soaps, especially around the injection site, may help.
• Ask your pharmacist: They can recommend over-the-counter antihistamines or soothing creams as needed

If you have experienced an injection site reaction, some people find taking medication out of the fridge first can reduce their symptoms - simply because the medication is not as cold when they inject it!

When to seek support

Reach out to a clinician if:

• You notice increased pain, swelling, spreading redness and skin inflammation or warmth at the injection site
• There’s discharge from the area, or your symptoms are not improving
• You're unsure whether it's safe to inject again

Whilst it is rare to have serious side effects from an injection site reaction, it is important to seek help urgently with your local medical emergency service if you experience:

• Swelling of your lips, tongue or throat 
• Widespread Rash
• Shortness of Breath

Summary

Injection site reactions are a common side effect of injectable medications, including tirzepatide and semaglutide, but they’re typically mild and manageable. Redness and itching are the most frequently reported symptoms, and simple steps, like rotating injection sites and using a cold compress, can make a big difference. Most reactions resolve on their own, but if anything doesn’t feel right, make sure you reach out for help.