Semaglutide
NHS information about the medicine semaglutide, including what it's used for, who can take it, how to take it and side effects.
What semaglutide is for
Semaglutide is a type of medicine called a GLP-1 agonist. It can be used to manage type 2 diabetes or treat obesity, by helping you lose weight when you combine it with exercise and changes to your diet.
You may also be offered semaglutide if you're living with obesity or overweight and:
- you have had a heart attack or stroke
- you have peripheral arterial disease (a condition affecting blood flow in the legs)
Semaglutide works for weight loss by reducing your appetite and helping you to feel fuller for longer.
For type 2 diabetes it works by lowering your blood sugar levels and helping your body to make more insulin if it's needed. It also slows digestion which keeps your blood sugar levels stable after meals.
If you need support to lose weight your doctor will refer you to a specialist weight management service. You'll only be prescribed semaglutide if your BMI meets the eligibility criteria.
If you're taking semaglutide for:
- weight loss, it comes as an injection that you give yourself once a week
- type 2 diabetes, it comes as an injection that you give yourself once a week and tablets that you take once a day
If you decide to get a private prescription for semaglutide injections (Wegovy), it's important to buy it from a registered pharmacy. There are some websites that sell fake weight loss medicines.
How to use semaglutide
Semaglutide comes as an injection that you give yourself once a week or tablets that you take once a day.
Always check the packet or leaflet that comes with your medicine. Ask a pharmacist or doctor for advice if you're not sure how to use it or you have any problems using it.
How to use semaglutide injections
Before you give yourself the injection, read the leaflet that comes with your medicine. It will show you how to get the injection pen ready.
Keep your injection pen in the fridge until you're ready to use it. Follow the instructions about how to store semaglutide on the packet or leaflet, as this may be different depending on the brand and type of pen.
When using semaglutide injections:
- try to inject on the same day each week – you can change the day of your injection as long as it's been at least 3 days since your last injection
- you can have it at any time of day
- inject into the fatty areas of your thigh, tummy or upper arm
- change the place you inject each week – you can use the same area but do not use the exact same spot
- inject into a different place if you inject insulin as well
How to take semaglutide tablets
When taking semaglutide tablets:
- take them as soon as you wake up – do not eat anything for at least 8 hours before you take semaglutide
- wait at least 30 minutes before eating, drinking or taking other medicines
- swallow tablets whole with half a glass of water (up to 120ml) – do not break, crush or chew the tablets
Ask a pharmacist for advice if you have problems swallowing tablets.
Side effects of semaglutide
Like all medicines, semaglutide can cause side effects, but not everyone gets them.
Common side effects
Common side effects of semaglutide include:
- feeling sick (nausea) and being sick (vomiting)
- constipation
- diarrhoea
- feeling tired
- itchy or red skin where you inject – redness maybe harder to see on brown or black skin
- hair loss
More about side effects
These are not all the side effects of semaglutide.
For a full list, see the leaflet that comes with your medicine or search for your medicine on the electronic medicines compendium website.
You can report any side effects you get on the Yellow Card website
Who can and cannot use semaglutide
Most adults can use semaglutide.
Semaglutide is not suitable for some people. For example, it may not be suitable if:
- you've had an allergic reaction to semaglutide or another GLP-1 agonist
- you have or have had an inflamed pancreas (acute pancreatitis)
Before taking semaglutide, tell your doctor or a pharmacist if you have any medical conditions.
Breastfeeding and semaglutide
Tell your doctor if you're breastfeeding. Semaglutide is not used while breastfeeding as the medicine passes into breast milk, and it's not known how it affects your baby.
Pregnancy and semaglutide
Tell your doctor if you're pregnant or get pregnant while using semaglutide. Semaglutide is not used during pregnancy as there's not enough information to say it's safe for your baby.
If you want to become pregnant, you should stop using semaglutide at least 2 months before you start trying.
Your doctor will recommend other medicines to treat type 2 diabetes while you’re pregnant.
Using semaglutide with other medicines, food and drink
There are some medicines, herbal remedies and supplements that may not mix well with semaglutide.
These include:
- some medicines to reduce blood clots such as warfarin
- levothyroxine, for an underactive thyroid
- insulin – your doctor or specialist nurse may need to adjust your dose
- other type 2 diabetes medicines like metformin and gliclazide
- a general anaesthetic (which puts you to sleep) or a sedative (which relaxes you) for an operation or dental procedure – tell the healthcare professional that you're using semaglutide
Before you use semaglutide, tell your doctor or a pharmacist if you're taking any other medicines, herbal remedies, vitamins or supplements.
Semaglutide and contraception
If there’s a chance you could get pregnant, you’ll need to use contraception while you’re using semaglutide.
Food, drink and alcohol with semaglutide
You'll need to eat a healthy, balanced diet while using semaglutide.
It's best not to drink alcohol, because it can increase side effects like feeling or being sick (nausea or vomiting).
Find out more about eating a healthy, balanced diet
Find out more about your medicine
To find out more about your medicine, you can:
- check the leaflet that comes with it
- search for your medicine leaflet on the electronic medicines compendium website
- speak to a pharmacist or doctor for advice – if you recently started taking it for type 2 diabetes or a heart condition or stroke, you can get help with newly prescribed medicines from a pharmacist as part of the New Medicine Service
