Liraglutide: daily GLP-1 injection explained

Liraglutide is a GLP-1 receptor agonist. The NHS gives two uses. For obesity it is sold as Saxenda, where it reduces appetite and helps you feel full for longer. For type 2 diabetes it is sold under names the NHS lists as Diavic and Zegluxen, where it lowers raised blood glucose, stimulates insulin production when needed, slows digestion so after-meal sugar stays steadier, and may help protect against heart disease.

It is a prescription-only medicine, and whether it is suitable is a decision for an assessing clinician. The NHS page does not state typical doses, so they are not given here.

Liraglutide is injected once a day under the skin of the thigh, tummy or upper arm, and the NHS says to rotate the injection site each day. A clinician or diabetes nurse teaches the pen technique before you start. Staying on a fixed time of day helps the routine, though the NHS page focuses on the missed-dose rule below.

If you are no more than twelve hours late, the NHS says inject straight away. If it has been more than twelve hours, skip the dose and continue as normal the next day. Never double up. If you have used more than your prescribed dose, the NHS says get help from NHS 111; do not drive yourself to A&E if told to attend, and take the pen with you.

The NHS lists nausea, vomiting, constipation, diarrhoea, headache, tiredness and irritation or redness at the injection site as common. Serious effects include anaphylaxis, low blood sugar with headache, vision change, dizziness, weakness, confusion, fast heartbeat and sweating, acute pancreatitis with severe stomach or back pain, and gallstones or gallbladder inflammation with severe abdominal pain.

The NHS says to call NHS 111 if you think you have a serious side effect. Avoid driving or using machinery if dizziness or vision problems occur.

• Severe abdominal pain that does not settle: seek urgent advice.

• Signs of a low sugar if you also take diabetes medicines: treat promptly and tell your team.

The NHS says liraglutide is not suitable if you have had an allergic reaction or serious side effect to it or another GLP-1 medicine, are aged seventy-five or over, have a stomach or bowel condition such as gastroparesis or inflammatory bowel disease, or have had acute pancreatitis. It notes that most adults and children aged ten and over can otherwise use it.

The NHS says liraglutide is not used in pregnancy because there is not enough information to say it is safe for the baby, and it is not used while breastfeeding because it is not known whether it passes into breast milk. Tell your doctor if you become pregnant, and use contraception during treatment if pregnancy is possible.

The NHS names other diabetes medicines (gliclazide, glimepiride, metformin, tolbutamide), insulin and other GLP-1 medicines (semaglutide, dulaglutide, exenatide, lixisenatide) as relevant to dose or combination decisions, and says to tell staff before general anaesthetic or sedation. Alcohol is best avoided because it can add to nausea and vomiting.

Speak to your prescriber before stopping, because the NHS says stopping suddenly is not recommended and a gradual reduction may be advised, particularly in diabetes. Suspected side effects can be reported through the Yellow Card scheme.