Which weight loss injections are available in the UK?

The injectable medicines licensed for weight management in the UK include Mounjaro (tirzepatide), Wegovy (semaglutide) and Saxenda (liraglutide). Mounjaro and Wegovy are injected once a week; Saxenda is injected once a day. All are prescription-only, so a registered prescriber must decide whether one is suitable for you.

Are weight loss injections safe?

These medicines have been assessed by the MHRA, but like all medicines they have side effects and are not suitable for everyone. Digestive side effects such as nausea are common, and there are rarer serious risks such as pancreatitis and gallbladder problems. A prescriber will check your medical history before prescribing and should monitor you during treatment.

Do I have to stay on a weight loss injection forever?

These medicines are designed to be used alongside long-term changes to diet and activity. Studies in which people stopped treatment have generally found that weight tends to return over time. How long you stay on treatment is a decision to make with your prescriber, based on your progress, side effects and goals.

Jabs

Weight loss injections: UK comparison and guide

Weight loss injections (sometimes called jabs) are prescription-only GLP-1-based medicines injected under the skin, either weekly or daily. Compare how they work, how they are dosed and what the evidence says.

How they work

The injectable medicines used for weight management in the UK all act on the GLP-1 receptor, which helps regulate appetite and slows how quickly the stomach empties. Mounjaro (tirzepatide) also acts on the GIP receptor. They are used alongside a reduced-calorie diet and increased physical activity, not instead of them.

The medicines

UK licensed
Mounjaro
tirzepatide · Injection once a week
A once-weekly injection that acts on both GIP and GLP-1 receptors. Licensed in the UK for weight management alongside diet and physical activity.
Mounjaro guide
UK licensed
Wegovy
semaglutide · Injection once a week
A once-weekly semaglutide injection licensed in the UK for weight management and, in some patients, to reduce cardiovascular risk.
Wegovy guide
UK licensed
Liraglutide (Saxenda / generic)
liraglutide · Injection once a day
An older, once-daily GLP-1 injection for weight management. Branded Saxenda has reportedly been discontinued in the UK, with generic liraglutide available; check current branded availability with your pharmacist or prescriber.
Liraglutide (Saxenda / generic) guide

Side-by-side comparison

Facts from the UK product information where verified. Unverified fields are marked.

Comparison of Mounjaro, Wegovy, Liraglutide (Saxenda / generic)
Attribute	Mounjaro	Wegovy	Liraglutide (Saxenda / generic)
Active ingredient	tirzepatide	semaglutide	liraglutide
Drug class	GIP/GLP-1 receptor agonist	GLP-1 receptor agonist	GLP-1 receptor agonist
Manufacturer	Eli Lilly	Novo Nordisk	Novo Nordisk (Saxenda); generic liraglutide from other manufacturers
Form	Injection	Injection	Injection
How often	once a week	once a week	once a day
Device	KwikPen (multi-dose pre-filled pen)	FlexTouch pen	Pre-filled pen
Starting dose	2.5mg	0.25mg	0.6mg
Dose range	2.5mg to 15mg	0.25mg to 7.2mg	0.6mg to 3mg
UK status	Licensed in the UK for weight management	Licensed in the UK for weight management	Licensed in the UK for weight management
NICE guidance	NICE TA1026 (December 2024)	NICE TA875 (March 2023)	NICE TA664 (December 2020)
Common side effects	Nausea, Diarrhoea, Constipation, Vomiting, Indigestion and reflux, Injection site reactions	Nausea, Diarrhoea, Constipation, Vomiting, Indigestion and reflux, Injection site reactions	Nausea, Diarrhoea, Constipation, Vomiting, Headache, Injection site reactions

Weight loss injections: UK comparison and guide

How they work

The medicines

Mounjaro

Wegovy

Liraglutide (Saxenda / generic)

Side-by-side comparison

Head-to-head comparisons

Related guides

Frequently asked questions