Saxenda vs. Wegovy: daily liraglutide against weekly semaglutide

Both are Novo Nordisk GLP-1 receptor agonists approved for chronic weight management, and both are injected under the skin. The practical gap is how long each molecule lasts. Liraglutide has an elimination half-life of about 13 hours, so Saxenda is injected every day; semaglutide's is about one week, so Wegovy is injected once a week. Saxenda starts at 0.6 mg and rises by 0.6 mg each week to 3 mg, reaching full dose in week five. Wegovy starts at 0.25 mg and climbs every four weeks through 0.5, 1 and 1.7 mg to 2.4 mg by week 17, with a 7.2 mg option for adults afterwards. Both are approved from age 12; Saxenda additionally requires adolescents to weigh more than 60 kg. Wegovy also exists as a 25 mg daily tablet and carries cardiovascular risk-reduction and MASH indications that Saxenda does not. Saxenda is being withdrawn for commercial reasons, not safety ones.

STEP 8, published in JAMA in January 2022, is the direct comparison. It randomized 338 adults with overweight or obesity and without diabetes to semaglutide 2.4 mg weekly, liraglutide 3.0 mg daily, or placebo, all with diet and activity counseling, for 68 weeks. Mean weight change was -15.8% on semaglutide, -6.4% on liraglutide and -1.9% on pooled placebo, a difference of 9.4 percentage points between the active drugs. The spread widened at higher thresholds: 70.9% on semaglutide lost at least 10% of body weight against 25.6% on liraglutide, 55.6% against 12.0% lost at least 15%, and 38.5% against 6.0% lost at least 20%. Each drug's own label tells a consistent story. Saxenda's label reports -7.4% against -3.0% on placebo after 56 weeks in its largest trial of 3,731 adults, while Wegovy's label reports -14.9% against -2.4% on placebo after 68 weeks in STEP 1. STEP 8 was open-label between the two active drugs, which limits how far its tolerability findings can be pushed, but the weight difference was large and statistically clear.

Gastrointestinal effects dominate both. In STEP 8, 84.1% on semaglutide and 82.7% on liraglutide reported a gastrointestinal event, against 55.3% on placebo, so the burden was similar. What differed was who stopped: 12.6% on liraglutide discontinued for adverse events, against 3.2% on semaglutide and 3.5% on placebo. Saxenda's label lists nausea in 39.3% against 13.8% on placebo, diarrhea 20.9%, constipation 19.4%, vomiting 15.7% and injection-site reactions 13.9%. Wegovy's label for the 2.4 mg injection lists nausea in 44% against 16%, diarrhea 30%, vomiting 24% and constipation 24%. Both labels carry the boxed warning for thyroid C-cell tumors in rodents, both are contraindicated with a personal or family history of medullary thyroid carcinoma or MEN 2, and both list pancreatitis, gallbladder disease, low blood sugar with insulin or sulfonylureas, and a heart-rate increase.

For most people starting today, the choice has largely been made for them. Saxenda is being discontinued, with last shipments to wholesalers in late January 2027 according to NovoCare's Saxenda page (checked 28 Sep 2026), and its savings offer closed to new enrollees in June 2023. Starting a drug with a known end date means a second switch within months. Wegovy suits people who want a weekly injection, the larger STEP 8 result and the cardiovascular indication; NovoCare lists it at $349 a month self-pay, with $199 a month for the first two months of 0.25 mg and 0.5 mg for new patients through 31 December 2026 (NovoCare Wegovy price guide, April 2026 edition, checked 28 Sep 2026). Saxenda remains reasonable for someone already stable and tolerating it well while a planned transition is arranged, or for anyone whose prescriber has reason to prefer liraglutide's short half-life, which clears the body faster if a side effect appears. A personal or family history of medullary thyroid carcinoma or MEN 2 rules out both. Neither should be combined with another GLP-1 medicine, and a move between them needs a prescriber-led plan, not a same-day swap.