Question 1

What is liraglutide?

Accepted Answer

Liraglutide is a manufactured copy of a gut hormone, redesigned to last about a day. A 2011 review calls it the first once-daily human GLP-1 analogue developed for type 2 diabetes, which makes it the oldest molecule of this family on the site. GLP-1 is short for glucagon-like peptide-1, a hormone the intestine releases when food arrives. The same review gives the number behind that schedule: the half-life of liraglutide is 13 h following subcutaneous injection, making it suitable for once-daily dosing. A half-life is how long it takes for half an injected amount to clear the blood. Most of this page follows from those thirteen hours.

Question 2

What is the difference between Victoza and Saxenda?

Accepted Answer

One molecule, three cartons, and what separates them is printed rather than chemical. Recall listings filed in March 2021 describe Saxenda (liraglutide) Injection, 18 mg/3 mL (6 mg/mL), 1 x 3 mL Prefilled Pen and, on the same day, a Victoza pen at the same 6 mg/mL. The liquid in those two pens sits at one strength, and what differs is the indication on the box and the daily amount the approved label carries. A 2019 development history records that weight loss led to approval of liraglutide at 3.0 mg for obesity, while the diabetes carton came first and runs lower, its published trials working at 1.2 mg and 1.8 mg a day. A third listing names Xultophy 100/3.6, which is the same molecule premixed with a long-acting insulin.

Question 3

Why is liraglutide a daily injection when the newer ones are weekly?

Accepted Answer

Because thirteen hours is how long an injected amount lasts. A 2021 dose-finding trial of cagrilintide, an experimental copy of a different appetite hormone, shows the contrast. Its participants self-injected either weekly cagrilintide at one of five amounts, once-daily liraglutide 3·0 mg, or a volume-matched placebo. The liraglutide arm injected seven times in the week the comparison arm injected once. The same split runs through the diabetes work, where 577 adults were randomized to weekly semaglutide 1.0mg or once-daily liraglutide 1.2mg. The interval belongs to the molecule rather than to anyone prescribing it, so a weekly amount and a daily amount are not two settings of one dial. How the schedules differ across the whole family is covered on the class pages.

Question 4

Does liraglutide actually work for weight loss?

Accepted Answer

Yes, by a margin the pooled trials can measure, and by less than the newer molecules beside it. A 2024 review in JAMA gathered the randomised evidence and reports that liraglutide was associated with 4.7% greater weight loss (18 RCTs; 6321 participants) than placebo. A 2025 systematic review gives the upper end of what it found: up to 5.8% after 26 weeks, in trials of liraglutide 3.0 mg once daily. The 2024 review puts semaglutide at 11.4% and tirzepatide 15 mg at 12.4% greater weight loss, which is the comparison most readers mean, and the class comparison page takes it up. Those percentages are averages across thousands of randomised participants, and nobody in any of those trials had the average. Each trial behind them also ran a diet or activity programme alongside the injection, so the figure describes a combination rather than a compound on its own.

Question 5

How much weight did the liraglutide trials measure, and over how long?

Accepted Answer

Every published figure is tied to a fixed endpoint. The SCALE Insulin trial ran 56 weeks in people with overweight or obesity and insulin-treated type 2 diabetes. In it, individuals were randomized to liraglutide 3.0 mg (n = 198) or placebo (n = 198), combined with intensive behavioral therapy. At 56 weeks, mean weight change was -5.8% for liraglutide 3.0 mg versus -1.5% with placebo. A separate phase 4 trial scanned the fat packed in around the organs of the belly, where mean change over a median of 36·2 weeks was -12·49% with liraglutide against -1·63% with placebo. The measured endpoints among the research behind this page are 26, 40 and 56 weeks, so a figure for one month is arithmetic performed on an average rather than something anyone measured, and those are not the same claim.

Question 6

How long did people stay on liraglutide in the trials?

Accepted Answer

The published horizon is about a year on the injection, and then a year watching what followed. A Copenhagen trial ran its four arms for a full year, and the same people were then invited to a post-treatment study with outcome assessments one year after treatment termination, at week 104. The children's trial and the insulin trial each ran 56 weeks, and that is how far the evidence reaches. A trial's length is a protocol decision rather than a boundary anyone discovered, so it does not describe how long a person may carry on. What people actually did is a separate measurement, and it is untidier: a 2025 review of real-world use reports high discontinuation rates of GLP-1RAs (20%-50%) within the first year, and the use of much lower doses than those evaluated in clinical trials.

Question 7

Why is Saxenda being discontinued?

Accepted Answer

The word is doing two jobs, and separating them is most of the answer. One sense is a company retiring a carton, and no regulatory notice among the research behind this page records a decision to stop selling Saxenda, so on that reading the record is silent. The other sense is people stopping, and a 2025 review of real-world use notes that many patients stop using them within the first year due to side effects or high costs of the medications. The supply picture has also changed in a way that is easy to mistake for a withdrawal: a Class II recall notice dated 2026 covers a liraglutide injection at 18 mg/3 mL (6 mg/mL) manufactured for Lupin Pharmaceuticals, which is a generic at the same strength as the branded pens. A brand sharing its market with generics and a medicine leaving the market are different things.

Question 8

How far into human testing has liraglutide gone?

Accepted Answer

Further than almost anything else on this site, and across four trial phases. The liver work was phase 2, run as a multicentre, double-blinded, randomised, placebo-controlled trial in four UK medical centres. The two trials in children and the insulin trial were phase 3. The fat-scanning study was a phase 4, single centre trial, which means it ran after approval had been granted. Liraglutide also has a heart-outcome trial of its own inside the largest pooling of them, a 2019 analysis in which seven trials, with a combined total of 56 004 participants, were included. LEADER is the liraglutide entry on that list. The useful point is not the phase numbers, but that every figure on this page traces back to a registered trial of a named, manufactured pen, which is exactly what an unlabelled vial carrying the same chemical name cannot offer.

Question 9

What did liraglutide do for blood sugar?

Accepted Answer

Blood sugar is what the molecule was built for, and it is the older half of the record. A 2011 review reports that liraglutide increases insulin secretion in a glucose-dependent manner, and improves the insulin response in patients. Glucose-dependent means the push on insulin follows the sugar level, which is why the same review records no major or minor hypoglycaemia in the patients it covers. Hypoglycaemia is blood sugar falling too low. HbA1c is the blood test that reflects average sugar over recent months, and the review reports that liraglutide got significantly more patients to their HbA1c targets than the comparators of its day. In that 577-person trial, mean HbA1c decreased by 1.7% with semaglutide and 1.0% with liraglutide. What one open-label trial settles, and what it does not, is comparison work taken up on the class comparison page.

Question 10

Has liraglutide been tested in children?

Accepted Answer

Yes, and further down the age range than anything else in this family. A 2025 phase 3a report notes that no medications are currently approved for obesity in children younger than 12 years of age. It then randomised children aged six to under twelve, and a total of 82 participants underwent randomization; 56 were assigned to the liraglutide group and 26 to the placebo group. At week 56, the mean percentage change from baseline in BMI was -5.8% with liraglutide and 1.6% with placebo. An earlier trial worked in patients who were 10 to less than 17 years of age, assigned to liraglutide or to placebo for 26 double-blind weeks. In those patients, glycated haemoglobin fell by 0.64 percentage points with liraglutide and rose by 0.42 with placebo. The investigators named the cost as well, reporting increased gastrointestinal adverse events in those patients. Both trials are small by adult standards, at 82 and 135 randomised.

Question 11

What else has liraglutide been tested for in people?

Accepted Answer

Two less obvious uses carry randomised evidence of their own. The first is the liver. A 2016 phase 2 trial gave subcutaneous injections of liraglutide (1·8 mg daily) or placebo to overweight patients with non-alcoholic steatohepatitis, which is fat-driven liver inflammation. Nine of 23 patients on liraglutide who had an end-of-treatment biopsy saw that inflammation resolve, against two of 22 on placebo. Fifty-two people were randomised in all, a signal rather than a settled answer. The second is polycystic ovary syndrome, or PCOS. A 2025 meta-analysis of liraglutide with metformin drew on 19 RCTs involving 1657 women with PCOS, and body-mass index fell against metformin alone in that pooled trial evidence. Its authors add the line that matters most, that the overall certainty of evidence was low due to risk of bias and heterogeneity. Low certainty across 1,657 women is still low certainty. A separate phase 4 entry called LIPT tested liraglutide in polycystic ovary syndrome and is recorded as completed.

Question 12

Which liraglutide findings exist only in animals?

Accepted Answer

Several findings quoted often about liraglutide have only been seen in rodents. A 2024 study reports that liraglutide significantly accelerates wound closure in diabetic mouse models, which is a long way from a healing claim in a person. A 2024 heart study used a mouse model of heart failure, where liraglutide on its own or with a diabetes tablet significantly improved diastolic function in those mice. Diastolic function is how well the heart relaxes and fills between beats. In a third, mice on a high-fat diet were given liraglutide, which not only improved glucose metabolism, but also ameliorated tissue damage in the livers of those animals. Mouse skin, mouse hearts and mouse livers are where those three results sit. Only the liver question also has a randomised human trial behind it, the phase 2 study described above.

Question 13

Is liraglutide approved, and what for?

Accepted Answer

Yes, and the approval is specific rather than general. A 2023 review in JAMA counts six medications currently approved by the US Food and Drug Administration for long-term use in obesity, and among them the GLP-1 agonists are semaglutide and liraglutide only. The 2019 development history records the same molecule in use for obesity as well as for type 2 diabetes, which is two regulatory decisions rather than one. What an approval does not reach matters as much. It covers a named pen, made by a named firm to a filed specification, for a named indication at a labelled daily amount. An approval granted for blood sugar is not one granted for weight, and an approval for adults is not one for children. None of it follows the chemical name into a different container.

Question 14

Is a compounded or research-grade liraglutide vial the same thing?

Accepted Answer

The molecule can be identical and the record still is not. The approved record belongs to the approved pen, and a compounded or research-grade vial carries the same chemical name and none of the label, the indication or the trial evidence that name earned. The enforcement register shows what a tracked supply looks like when something goes wrong with it. Three liraglutide listings filed on one day in March 2021, covering the Saxenda, Victoza and Xultophy sample pens, were pulled over temperature abuse, because product samples were stored at temperatures below 32* F which is not in accordance with storage requirements. A 2026 listing covers a generic pen withdrawn over the presence of particulate matter: a white thread-like structure in the cartridge. Both notices exist because each batch was filed, numbered and traceable to a named firm.

Question 15

What is documented about liraglutide side effects?

Accepted Answer

One paragraph, because the class page carries the depth. A 2024 review in JAMA gives the common ones for these medicines as nausea (28%-44%), diarrhea (21%-30%), and constipation (11%-24%) among the patients in its trials. Two records are specific to liraglutide, and the first is a European pharmacovigilance analysis that identified 31,444 adverse event reports across three molecules, of which liraglutide accounted for 16,748, or 53.2%. The same analysis counted nine deaths, eight of them with liraglutide and one with semaglutide. A reading of the FDA's reporting system found liraglutide had significance in both signals in dysphonia, dysgeusia, tinnitus, and Bell's palsy, where dysphonia is hoarseness and dysgeusia is a distorted sense of taste. Report counts are not rates, and they climb with how long and how widely something has been used. Liraglutide has been in use longer than either weekly molecule it is usually set against.

Question 16

How does liraglutide work?

Accepted Answer

This part was mapped after the clinical results arrived, and mostly in rodents. The appetite effect appears to run through a small cluster of brain cells called the arcuate nucleus. A 2014 study in rats and mice concluded that receptors on two appetite-controlling cell types in that cluster likely mediate the weight loss liraglutide produces. A 2022 mouse study added the delivery route, finding that liraglutide is shuttled into the mouse hypothalamus by cells called tanycytes, bypassing the blood-brain barrier that normally keeps large molecules out. The gut side is plainer: the 2011 review reports that liraglutide delays the rate of gastric emptying, reduces energy intake and exerts a moderate suppression on hunger in the patients it covers. Those are rodent maps of a human outcome, and the trials themselves measured what happened to weight and to blood sugar rather than which cells did the work.

Liraglutide