Liraglutide

What is liraglutide?

Liraglutide is a once-daily injectable drug that mimics GLP-1, a gut hormone that helps control blood sugar and appetite. It was developed by Novo Nordisk and approved by the FDA in 2010 as Victoza for type 2 diabetes. A higher-dose version, Saxenda, was approved in 2014 for chronic weight management.

Liraglutide was one of the first GLP-1 drugs to be widely used and the first to show a clear benefit on heart outcomes in people with type 2 diabetes. It has since been overtaken by once-weekly drugs such as semaglutide and tirzepatide, which lead to more weight loss. But it remains widely prescribed, and generic versions have been available in the US since 2024, which makes it one of the lower-cost options in its class.

How liraglutide works

After a meal, your gut releases GLP-1. It tells the pancreas to release insulin when blood sugar is high, tells the liver to make less sugar, slows how fast the stomach empties, and signals the brain that you are full. Natural GLP-1 is broken down within minutes. Liraglutide is a modified version that lasts long enough to be injected once a day.

The result is lower blood sugar, smaller appetite and, for most people, weight loss. Because the insulin effect depends on blood sugar being high, liraglutide on its own rarely causes low blood sugar.

In more precise terms, liraglutide shares 97% of its amino acid sequence with human GLP-1 and carries a 16-carbon fatty acid attached through a glutamic acid spacer. The fatty acid binds albumin in the blood and makes the molecules cluster at the injection site. Both slow absorption and protect against breakdown by the enzyme DPP-4, giving a half-life of about 13 hours. It acts on the GLP-1 receptor in the pancreas, gut and brain, including appetite-regulating areas of the hypothalamus and brainstem.

What the research shows on liraglutide

Liraglutide has an extensive evidence base from large randomized trials, most of them funded by its manufacturer.

For heart health, the LEADER trial enrolled 9,340 people with type 2 diabetes at high cardiovascular risk and followed them for a median of 3.8 years. Heart attack, stroke or cardiovascular death occurred in 13.0% of people on liraglutide and 14.9% on placebo. Cardiovascular deaths and deaths from any cause were also lower.² The trial was funded by Novo Nordisk and the National Institutes of Health.²

For weight loss, the SCALE trial randomized 3,731 adults without diabetes to the 3.0 mg dose or placebo for 56 weeks. People on liraglutide lost an average of 8.4 kg, compared with 2.8 kg on placebo. About 63% lost at least 5% of their body weight, versus 27% on placebo, and about a third lost more than 10%, versus 11%.⁴ In adolescents with obesity, liraglutide reduced BMI more than placebo, but BMI rose again after treatment stopped.⁷ A trial in children aged 6 to under 12 also found a greater reduction in BMI than placebo.³

Head-to-head trials show its limits. In STEP 8, weekly semaglutide led to a 15.8% average weight loss over 68 weeks versus 6.4% with daily liraglutide.¹ In type 2 diabetes, the SUSTAIN 10 trial of 577 adults found that semaglutide lowered HbA1c by 1.7 points versus 1.0 with a common liraglutide dose, and weight by 5.8 kg versus 1.9 kg, over 30 weeks.⁸

Two other findings stand out. In 195 adults who first lost an average of 13.1 kg on an eight-week low-calorie diet, combining liraglutide with regular exercise kept off more weight and fat than either alone over a year.⁵ In a small phase 2 trial in people with the liver disease now called MASH, liraglutide resolved the condition in more patients than placebo, though the trial was small.⁶

Studied for: Type 2 diabetes, Chronic weight management.

Liraglutide reference data

Liraglutide dosage in published research

How liraglutide is used in practice

Liraglutide is prescribed by primary care doctors, endocrinologists and obesity specialists. It comes in prefilled pens and is injected under the skin once daily. The dose is increased step by step over several weeks to reduce nausea. Victoza is used for type 2 diabetes. Saxenda is used for weight management in adults and adolescents with obesity, alongside diet and activity.

Many telehealth weight-loss services prescribe it, especially since generics lowered the price and when insurers will not cover weekly drugs. Because approved generics exist, there is little reason to use compounded liraglutide. Products sold online as research chemicals are not regulated and should be avoided.

Liraglutide risks and side effects

The most common side effects are nausea, diarrhea, vomiting, constipation and headache. In SCALE they were mostly mild or moderate.⁴ In the adolescent trial, digestive side effects affected about 65% of those on liraglutide versus 37% on placebo, and about 10% stopped treatment because of side effects.⁷

Serious but less common risks include gallbladder disease, pancreatitis and dehydration that can strain the kidneys. Liraglutide also raises resting heart rate slightly. In the weight-maintenance trial, faster heart rate and gallstones were seen more often with liraglutide alone than with liraglutide plus exercise.⁵

Liraglutide carries a boxed warning based on thyroid C-cell tumors in rodents. It should not be used by people with a personal or family history of medullary thyroid carcinoma or with multiple endocrine neoplasia type 2. It should not be used in pregnancy. Combined with insulin or sulfonylureas, it can cause low blood sugar. Because it slows stomach emptying, it can affect absorption of oral medicines and may matter before surgery under anesthesia. Weight usually returns after stopping.

Reported side effects

Alternatives to liraglutide

For weight loss, once-weekly semaglutide (Wegovy) and tirzepatide (Zepbound) produce substantially more weight loss in trials. Other approved options include phentermine-topiramate, naltrexone-bupropion and orlistat. Bariatric surgery remains the most effective option for severe obesity.

For type 2 diabetes, alternatives include weekly semaglutide (Ozempic), dulaglutide, tirzepatide (Mounjaro), SGLT2 inhibitors such as empagliflozin, and metformin. The right choice depends on heart and kidney risk, cost and tolerance.

Questions for a clinician

• What evidence applies to my situation, and at what level?
• What established alternatives should I consider first?
• What monitoring would be necessary, and how often?