Short answer: Byetta (exenatide) is injected twice a day within 60 minutes before meals; Victoza (liraglutide) once a day at any time. Both treat type 2 diabetes; Victoza is also approved from age 10 and to lower heart risk.12 In LEAD-6, a 26-week head-to-head trial, HbA1c fell 1.12 points on liraglutide 1.8 mg vs 0.79 on exenatide 10 mcg twice daily.3
| Byetta (exenatide) | Victoza (liraglutide) | |
|---|---|---|
| Shots | Twice a day, within 60 minutes before the morning and evening meals; never after a meal1 | Once a day2 |
| Label dosing | 5 mcg twice daily; 10 mcg twice daily recommended after 1 month1 | 0.6 mg daily for a week, then 1.2 mg; may go to 1.8 mg2 |
| Approved for | Blood sugar in adults with type 2 diabetes1 | Blood sugar in type 2 diabetes from age 10; lowering heart attack, stroke and cardiovascular death in adults with heart disease2 |
| Boxed warning | None1 | Thyroid C-cell tumors seen in rodents2 |
| Nausea in label trials | 44% vs 18% on placebo (with metformin and/or a sulfonylurea)1 | 18% (1.2 mg) and 20% (1.8 mg) vs 5%2 |
| Kidney rule | Not recommended with creatinine clearance under 301 | No dose change; limited experience in end-stage disease2 |
| Missed dose | Skip it; resume with the next scheduled dose1 | Resume with the next scheduled dose; after more than 3 days off, restart at 0.6 mg2 |
| LEAD-6 HbA1c change (26 weeks) | −0.79 points3 | −1.12 points3 |
| LEAD-6 weight change | −2.87 kg3 | −3.24 kg3 |
Yes. LEAD-6 randomized 464 adults with type 2 diabetes, already on metformin, a sulfonylurea or both, to liraglutide 1.8 mg once daily (n=233) or exenatide 10 mcg twice daily (n=231) for 26 weeks, open label. From a starting HbA1c of 8.2%, HbA1c fell 1.12 points vs 0.79 (difference −0.33), and 54% vs 43% reached an HbA1c under 7%. Weight loss was similar: −3.24 kg vs −2.87 kg.3
Nausea lasted for a shorter time with liraglutide, and minor low blood sugar was less frequent: 25.5% vs 33.6% of people. Two people on exenatide with a sulfonylurea had a major low blood sugar episode. The trial was funded by Novo Nordisk, which makes Victoza.3
Victoza carries a boxed warning for thyroid C-cell tumors seen in rodents and is not used with a personal or family history of medullary thyroid cancer or MEN 2.2 Byetta has no boxed warning but lists low platelets caused by the drug and antibodies among its warnings.1 Both warn about pancreatitis, low blood sugar with insulin or a sulfonylurea, kidney injury from fluid loss, gallbladder disease and never sharing a pen.12
Any switch between them is planned with your prescriber. More detail: Byetta side effects, Victoza side effects, the Byetta and Victoza dosing schedules, what to do if you miss a Byetta dose or miss a Victoza dose, and the Exenatide and Liraglutide guides.