Liraglutide (Saxenda / Victoza)

What liraglutide is

Liraglutide is a derivative of the gut hormone GLP-1, prescription-only and approved in the EU under two names: Victoza for type 2 diabetes and Saxenda for weight management. Since July 2026 there are also chemically manufactured preparations of the same active substance, Ablymico for weight management and Liraglutide STADA for diabetes.

What is rated is the state of knowledge. Liraglutide is well studied: randomized trials with thousands of participants, an endpoint trial in type 2 diabetes and more than 15 years of post-marketing surveillance. For placing it in the biohacking context, what matters most is the comparison with the newer substances semaglutide and tirzepatide.

How it works

Liraglutide activates the GLP-1 receptor. Gastric emptying is delayed, the feeling of fullness increases, insulin release is enhanced and glucagon release is dampened. Less hunger means less food intake, and this results in weight loss.

The target is the same as with semaglutide. The practical difference lies in the duration of action: liraglutide is injected once daily, semaglutide once a week. Tirzepatide and retatrutide additionally act on further hormone receptors, liraglutide only on the GLP-1 receptor.

What the studies show

SCALE: weight after 56 weeks

Pi-Sunyer 2015 (NEJM) randomized 3,731 adults without diabetes with a BMI of 30 or more, or 27 or more with dyslipidemia or high blood pressure, in a 2:1 ratio; both groups received lifestyle counseling. After 56 weeks, weight loss was 8.4 versus 2.8 kg, p<0.001. The most common events were mild to moderate nausea and diarrhea; serious adverse events occurred in 6.2 versus 5.0 percent. The study was funded by the manufacturer.

Three years in prediabetes

le Roux 2017 (Lancet) followed 2,254 participants with prediabetes from the same trial over 160 weeks. The time to a diabetes diagnosis was 2.7 times as long on liraglutide as on placebo, hazard ratio 0.21 (0.13 to 0.34). After three years, weight was 6.1 versus 1.9 percent below baseline. Only half of the participants stayed until the end, and those who dropped out were not followed further.

LEADER: heart and circulation in type 2 diabetes

Marso 2016 (NEJM) randomized 9,340 patients with type 2 diabetes and high cardiovascular risk, with a median follow-up of 3.8 years. Major events occurred in 13.0 versus 14.9 percent, hazard ratio 0.87 (0.78 to 0.97). Cardiovascular death 4.7 versus 6.0 percent, death from any cause 8.2 versus 9.6 percent. The hazard ratio is a relative measure; the difference between relative and absolute effect matters here too. In absolute terms, the groups differ by 1.9 percentage points on the primary endpoint; arithmetically, that is around 53 people treated over 3.8 years per event prevented. This value was calculated from the event rates and is not stated in the abstract.

STEP 8: liraglutide versus semaglutide

Rubino 2022 (JAMA) compared daily liraglutide with weekly semaglutide over 68 weeks in 338 adults with overweight without diabetes, open-label against each other, each blinded against placebo. Weight fell by 6.4 versus 15.8 percent, a difference of 9.4 percentage points. At least 10 percent was lost by 25.6 versus 70.9 percent. 27.6 percent on liraglutide and 13.5 percent on semaglutide stopped treatment early; gastrointestinal complaints were equally common at 82.7 and 84.1 percent.

SCALE Teens: adolescents

Kelly 2020 (NEJM) treated 251 adolescents with obesity for 56 weeks. A BMI reduction of at least 5 percent was achieved by 43.3 versus 18.7 percent. After stopping, BMI rose again more on liraglutide than on placebo. 64.8 versus 36.5 percent had gastrointestinal complaints; 10.4 percent discontinued because of side effects.

Where the data stop

• Heart protection in overweight without diabetes. LEADER included only people with type 2 diabetes. An endpoint trial like SELECT for semaglutide does not exist for liraglutide in overweight without diabetes.
• Equivalence with semaglutide. In the only head-to-head comparison, people lost less than half as much weight with liraglutide, and more than twice as many stopped treatment early.
• A lasting effect after stopping. In adolescents, BMI rose again after stopping. The three-year data in adults say nothing about the period afterwards, because those who dropped out were not followed further.
• Products from outside the pharmacy. The studies apply to the approved medicine. They do not apply to products from the gray market.

Status, approval and legal

Liraglutide is approved in the EU and prescription-only in Germany. Victoza was approved on June 30, 2009 for type 2 diabetes, Saxenda on March 23, 2015 for weight management. Saxenda is approved for adults with a BMI of 30 or more, or 27 or more with a weight-related comorbidity, and for adolescents aged 12 and over with obesity and a body weight above 60 kg. According to the approval, the maintenance dose is 3.0 mg daily. Anyone who has not lost at least 5 percent after 12 weeks on this dose should stop treatment according to the prescribing information.

On July 15, 2026, two preparations from STADA were approved whose active substance is manufactured chemically rather than in living cells: Ablymico for weight management and Liraglutide STADA for type 2 diabetes.

For weight loss, liraglutide is not covered by statutory health insurance: § 34 SGB V (German Social Code, Book V) excludes medicines for slimming and for regulating body weight. Liraglutide is not on the World Anti-Doping Agency’s 2026 Prohibited List; only semaglutide and tirzepatide are in the monitoring program.

Safety

The most common side effects affect the stomach and gut, above all nausea and diarrhea. In SCALE they were mostly mild to moderate; in adolescents, 64.8 percent had such complaints versus 36.5 percent on placebo.

Diseases of the gallbladder and bile ducts occur more often under GLP-1 receptor agonists. A meta-analysis of 76 randomized trials with 103,371 people found a relative risk of 1.37, 2.29 in weight-loss trials, with higher risk at higher doses and longer use. Inflammation of the pancreas did not occur more often on liraglutide than on placebo in LEADER.

On suicidal thoughts, the safety committee of the European Medicines Agency evaluated clinical trials, spontaneous reports and two studies using health data in April 2024 and found no evidence of a causal link.

Sources

• Pi-Sunyer X et al., N Engl J Med 2015 – SCALE Obesity and Prediabetes, RCT with 3,731 adults, 56 weeks
• le Roux CW et al., Lancet 2017 – three years of liraglutide in prediabetes, 2,254 participants
• Marso SP et al., N Engl J Med 2016 – LEADER, cardiovascular endpoints in 9,340 patients with type 2 diabetes
• Rubino DM et al., JAMA 2022 – STEP 8, semaglutide versus liraglutide, 338 participants
• Kelly AS et al., N Engl J Med 2020 – liraglutide in adolescents with obesity, 251 participants
• He L et al., JAMA Intern Med 2022 – meta-analysis of gallbladder and biliary disease under GLP-1 receptor agonists
• EMA – Saxenda, European public assessment report (EPAR)
• EMA – Ablymico (liraglutide, STADA), European public assessment report
• EMA/PRAC, meeting of April 8–11, 2024 – no causal link between GLP-1 receptor agonists and suicidal thoughts
• WADA Prohibited List 2026 (bilingual version by JADA)