Frequently asked questions

As with all medicines, you may get some side effects while taking weight loss injections. This is most likely when you first start taking treatment or after you’ve increased your dose. These side effects tend to go away within a few weeks and ease over time. Speak to your doctor if side effects aren’t getting better.

To find out more about any side effects you can expect for your weight loss injection, read the patient information leaflet that comes with your medicine.

Very common and common side effects of weight loss injections include:

• nausea (feeling sick)
• vomiting (being sick)
• diarrhoea or constipation
• headaches
• dizziness
• dry mouth
• injection site reactions, such as itching or redness

Serious weight loss injection side effects can include:

• common (Wegovy only): complications of diabetic retinopathy (if you have diabetes)
• uncommon: an inflamed pancreas (acute pancreatitis)
• rare: a serious allergic reaction (anaphylaxis)

If you experience side effects talk to your doctor or other healthcare professional. This includes any possible side effects not listed in the package leaflet. Call 999 or go to A&E if you get symptoms of any serious side effects.

Weight loss injections work by imitating natural hormones in your body that regulate your appetite and hunger levels. Mounjaro, Wegovy and Saxenda act on the hormone GLP-1 and Mounjaro acts on a second hormone too; GIP.

These hormones are released after you eat, attaching to receptors that send signals to your brain telling it that you’ve eaten and are full. Weight loss injections imitate these hormones, so you’ll feel fuller even while eating less. They also reduce how quickly your stomach empties after eating, which keeps you feeling full and so less likely get hunger urges.

If the missed Mounjaro® dose was 4 days ago or less:

• Take the missed Mounjaro® dose as soon as possible.
• Continue the usual weekly dosing schedule after taking the missed dose.

If more than 4 days have passed since the missed dose:

• Skip the missed Mounjaro® dose.
• Take the next scheduled weekly dose on the regular day.

Important dosing safety rule: Do not take two Mounjaro® doses within 3 days of each other.

• If the next scheduled dose is more than 2 days away (48 hours), take the missed dose as soon as possible.
• If the next scheduled dose is less than 2 days away (48 hours), skip that dose and take your next dose on the regularly scheduled day.
• If it‘s been 2 or more weeks (14 days) since your last dose, take the next dose on the regularly scheduled day or talk with your healthcare professional about how to restart your treatment.

Yes, you can drink alcohol while taking your weight loss treatment, but it should be in moderation. Alcohol and Mounjaro or Wegovy don’t specifically interact, but combining the two can still pose potential risks. GLP-1 medicines work by slowing gastric emptying and reducing appetite. This can sometimes cause nausea or stomach discomfort. And alcohol may make this worse.

In addition, drinking large amounts of alcohol can lead to side effects, such as low blood sugar. This can cause you to consume extra calories, which obviously negatively impacts your weight loss slowing your progress.

Women should try to limit themselves to one drink per day and men should not drink more than two. Try to avoid drinking on an empty stomach to reduce the risk of nausea and stomach irritation.

• Don’t drop your pen or knock it against hard surfaces.
• Keep your pen away from liquids.
• If you think that your pen may be damaged, don’t use it or try to fix it. Use a new pen.
• Keep the pen cap on until you are ready to inject, to reduce the risk of infection. Your pen will not be sterile if it is stored without the cap, if you pull the pen cap off and put it on again, or if the pen cap is missing.
• Store the Mounjaro® pen in the fridge between 2 and 8°F (36 and 46°F). Do not freeze.
• Store in the original, unopened packaging.

Since GLP-1s work by suppressing appetite, one of the first things you may notice after stopping taking your treatment is that you feel more hungry again. This is obviously going to encourage you to consume more food. It’s one of the reasons why people often quickly gain some of the weight they’ve successfully lost. It important to realise that obesity is a chronic condition and can’t be cured. It needs long-term treatment.

Speak to your doctor if you’re considering coming off your treatment and they can advise about the best way of doing so to support you in maintaining the weight loss you’ve worked so hard for. During your time on the treatment, if you’ve managed to make some healthy lifestyle changes too, it will be easier to keep the weight off.