Speak to a healthcare professional
Speak to a healthcare professional if you’re thinking about taking weight loss medication and have an eating disorder.
Medications for diabetes and weight loss can be used to lower blood sugar in people with type 2 diabetes. They’re also used as a treatment for obesity as part of long-term weight management.
Types of weight loss medication
These types of medications include:
semaglutide tirzepatide liraglutide
Types of semaglutide
Ozempic® medication for type 2 diabetes that you inject to manage blood glucose levels Rybelsus® medication that comes in tablet form that can be used to treat type 2 diabetes Wegovy® medication that you inject to treat obesity
Types of tirzepatide
Tirzepatide is available under the brand name Mounjaro®. It’s a medication you inject. It’s prescribed to treat type 2 diabetes and obesity.
Types of liraglutide
Liraglutide is available under 2 brand names:
Victoza® medication that you inject to treat type 2 diabetes Saxenda® medication that you inject to treat obesity
Buying medicines online
Don’t buy these medicines online without speaking to a qualified healthcare professional.
If buying online you can check that your pharmacy is registered with the General Pharmaceutical Council to make sure it’s a genuine prescriber or pharmacy.
You can report someone who you think is selling medicines or medical devices illegally on the MHRA website.
Orlistat
There is a different type of weight loss pill used to treat obesity called Orlistat.
How weight loss medications work
These medications increase the level of hormones that are produced naturally by the stomach when you eat.
When taking the medication as prescribed, on average, people lose 5 to 20% of their starting bodyweight.
Speak to your prescriber if your medication is not working as well as expected.
The medications works by helping your body produce more insulin when needed. They also reduce the amount of glucose or sugar produced by the liver.
The medications also slows down how quickly food is digested. This can lead to weight loss as the digestion process can help you stay fuller for longer.
Some of your brain’s signals around food can change. This means you experience fewer cravings for food. This is also known as reducing food noise.
Taking weight loss medication alongside other medications
Weight loss medications can change how your body absorbs certain drugs into your stomach. This may make another medication less effective.
Talk to your prescriber if you take other medication before starting any treatment.
Taking weight loss medication and HRT
Taking weight loss medication can affect the effectiveness of oral HRT treatment.
Speak to your prescriber before taking any treatment.
Taking tirzepatide and oral contraceptives
Tirzepatide (Mounjaro) may reduce the effectiveness of oral contraceptives like the combined pill. You should use additional non-oral contraception, like condoms, for the first 4 weeks and for 4 weeks after any increase in dose.
There is no evidence to show that other weight loss medicines, like semaglutide, reduces the effectiveness of oral contraceptives.
Pregnancy and breastfeeding
Diabetes and weight loss medication should not be taken while you’re:
pregnant trying to become pregnant breastfeeding
If you’re using a weight loss medication and think you may be pregnant, speak to your prescriber as soon as possible.
Taking weight loss medication before an operation
Diabetes and weight loss medication slow the rate that your stomach empties. This means that there may be small risk of complications if you’re under anaesthetic.
If you have an operation coming up, you should continue to take your medicine as normal. Don’t stop the prescribed dose until you have talked to your anaesthetist and healthcare team about it.
How to take weight loss medication
Semaglutide, tirzepatide and liraglutide medication can be given in 2 different ways. These are:
oral tablets injections
Your prescriber will tell you how to take your medication. You should follow the directions on the label. Read the patient information leaflet that comes with your medicine too.
You should always start on the lowest dose under your prescriber’s advice. Slowly work your way up to the dose best suited to you, over time. This may not be the top dose as best treatment dose is very individual.
You should also let your prescriber know if you’re taking other prescribed medicines.
Read more about specific advice on diet and physical activity when taking weight loss medication
Switching types of medicine
While these medications are similar you should not switch from one to another before speaking to your prescriber.
Stopping weight loss medication
Talk to your prescriber if you’re thinking of stopping using weight loss medications. You may need to move onto a lower dose before stopping.
Read more about how to maintain weight loss
Possible side effects of semaglutide, tirzepatide and liraglutide
You should check the patient information leaflet that comes with your medicine for a full list of side effects.
Common side effects
Side effects of these medicines include:
constipation diarrhoea painful stomach cramps and abdominal pain nausea and vomiting headaches fatigue hypoglycaemia (low blood sugar)
Less common side effects
Less common side effects of these medications include:
changes to your vision kidney failure pancreatitis problems with your gallbladder an allergic reaction like a skin reaction to where the medication was injected
If you’re worried about side effects, speak to your prescriber.
Reporting side effects
You can report suspected side effects of vaccines, medicines and medical devices through the Yellow Card Scheme.
This can be done by:
visiting the Yellow Card Scheme website phoning the free Yellow Card hotline on 0800 731 6789 (available Monday to Friday, 9am to 5pm)