Dr. Pep

Peptides · GLP-1 receptor agonist

Liraglutide: what the studies show

Every line below comes from a study, label or regulator record, checked by two models, with the source linked. Information, not medical advice. For adults 18+.

What it is

  • Liraglutide is a GLP-1 receptor agonist given as a daily injection under the skin. It is sold as Victoza (type 2 diabetes) and Saxenda (weight management). Generic liraglutide and the insulin combination Xultophy also exist.[1][2][3][4]
  • The Victoza label (2025) lists two uses: better blood-sugar control in adults and children 10 and older with type 2 diabetes, and fewer major heart events in adults with type 2 diabetes and established heart disease. The Saxenda label (2026) lists weight reduction and long-term weight maintenance, with diet and exercise, in adults with obesity, adults with overweight plus a weight-related condition, and children 12 and older with obesity who weigh over 60 kg.[1][2]

Bottom line

  • Liraglutide is an approved prescription drug. Large randomised trials show weight loss and fewer heart events, but the weight loss is smaller than with newer weekly drugs, nausea and vomiting are very common, and it carries a boxed warning about thyroid tumours seen in rodents. Compounded or 'research' liraglutide is not an FDA-reviewed product.[5][6][7][2][8]

What the human studies found

  • SCALE Obesity and Prediabetes (double-blind RCT, 3,731 adults with obesity or overweight and no diabetes, 56 weeks, with lifestyle counselling): liraglutide 3.0 mg daily lost a mean 8.4 kg versus 2.8 kg on placebo. 63.2% lost at least 5% of body weight versus 27.1%, and 33.1% lost more than 10% versus 10.6%. Nausea and diarrhoea were the most common side effects.[5]
  • SCALE Diabetes (RCT, 846 randomised adults with overweight or obesity and type 2 diabetes, 56 weeks): weight loss was 6.0% on 3.0 mg, 4.7% on 1.8 mg and 2.0% on placebo.[9]
  • SCALE Maintenance (RCT, 422 adults who first lost at least 5% on a low-calorie diet, 56 weeks): liraglutide 3.0 mg gave a further 6.2% loss versus 0.2% on placebo. 81.4% kept the first 5% loss versus 48.9% on placebo.[10]
  • LEADER (double-blind RCT, 9,340 adults with type 2 diabetes and high heart risk, median 3.8 years): heart death, non-fatal heart attack or non-fatal stroke occurred in 13.0% on liraglutide versus 14.9% on placebo (hazard ratio 0.87). Heart death alone was 4.7% versus 6.0%.[6]
  • Head to head with semaglutide: in STEP 8 (RCT, 338 adults without diabetes, 68 weeks), weekly semaglutide 2.4 mg gave -15.8% body weight versus -6.4% for daily liraglutide 3.0 mg. Stomach and bowel side effects were reported by 84.1% on semaglutide and 82.7% on liraglutide.[7]

Known risks and side effects

  • Boxed warning on both labels: risk of thyroid C-cell tumours, including medullary thyroid cancer. The labels say routine calcitonin tests or thyroid ultrasound are of uncertain value for early detection.[1][2]
  • In the Saxenda label's adult trials, nausea was 39.3% versus 13.8% on placebo, diarrhoea 20.9% versus 9.9%, constipation 19.4% versus 8.5%, and vomiting 15.7% versus 3.9%. In the 56-week trials about 10% stopped because of side effects versus 4% on placebo.[2]
  • Other label warnings: acute pancreatitis (including fatal cases), gallbladder disease, low blood sugar when used with insulin or a sulfonylurea, higher heart rate, acute kidney injury from fluid loss, serious allergic reactions, and pulmonary aspiration during anaesthesia or deep sedation.[2][1]
  • A meta-analysis of GLP-1 drugs found no clear rise in bowel obstruction overall, but a higher risk with liraglutide than with semaglutide.[11]

Legal status

  • FDA approved: Victoza (label 2025), Saxenda (label 2026), a generic liraglutide injection (label 2026) and Xultophy (insulin degludec plus liraglutide, label 2025).[1][2][4][3]
  • In a 2026 press announcement FDA proposed to exclude semaglutide, tirzepatide and liraglutide from the 503B bulks list, finding no clinical need for outsourcing facilities to compound them from bulk substances. Public comments were open until June 29, 2026. The final decision was not in the records held.[8]
  • FDA says compounded GLP-1 drugs are not reviewed for safety, effectiveness or quality, and should be used only when an approved drug cannot meet the patient's need (page updated 2026).[12]

Sources

  1. [1] Victoza (Liraglutide) Injection prescribing information
  2. [2] Saxenda (Liraglutide) Injection, Solution prescribing information
  3. [3] Xultophy 100/3.6 (Insulin Degludec And Liraglutide) Injection, Solution prescribing information
  4. [4] Liraglutide Injection prescribing information
  5. [5] A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management.
  6. [6] Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes.
  7. [7] Effect of Weekly Subcutaneous Semaglutide vs Daily Liraglutide on Body Weight in Adults With Overweight or Obesity Without Diabetes: The STEP 8 Randomized Clinical Trial.
  8. [8] FDA: FDA Proposes to Exclude Semaglutide, Tirzepatide, and Liraglutide on 503B Bulks List (press announcement)
  9. [9] Efficacy of Liraglutide for Weight Loss Among Patients With Type 2 Diabetes: The SCALE Diabetes Randomized Clinical Trial.
  10. [10] Weight maintenance and additional weight loss with liraglutide after low-calorie-diet-induced weight loss: the SCALE Maintenance randomized study.
  11. [11] Evaluating bowel obstruction and ileus events in patients on GLP-1 receptor agonists: a systematic review and meta-analysis.
  12. [12] FDA: FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss (updated 2026)