Saxenda Side Effects and Results: What the Evidence Shows
Saxenda's most common side effects — those reported in 5% or more of patients — are nausea, diarrhea, constipation and vomiting. In the 56-week pivotal trial, people on liraglutide 3 mg lost an average of 8.4 kg versus 2.8 kg on placebo, and 63.2% lost at least 5% of body weight.
Semaglutides.org provides information only, not medical advice. Talk to a licensed provider about your own care before making changes. Some telehealth links are affiliate links and are labeled where they appear.
Saxenda (liraglutide 3 mg) is a once-daily GLP-1 receptor agonist injection approved for chronic weight management. Its most common side effects — the adverse reactions reported in 5% or more of patients — are digestive: nausea, diarrhea, constipation, vomiting, dyspepsia and abdominal pain, along with headache, fatigue, dizziness, injection site reactions and hypoglycemia [1][6]. In the 56-week pivotal trial of 3,731 adults, the liraglutide group lost an average of 8.4 kg (about 18.5 pounds) versus 2.8 kg on placebo, a difference of −5.6 kg (95% CI −6.0 to −5.1) [2][3].
The label also carries a boxed warning about thyroid C-cell tumors seen in rats and mice, and it lists serious risks including acute pancreatitis, gallbladder disease, kidney injury from fluid loss, and severe gastrointestinal reactions [1][6]. An independent Cochrane review of 24 RCTs and 9,937 participants found liraglutide likely increases the share of people losing at least 5% of their body weight (RR 2.10, 95% CI 1.80–2.45, moderate certainty), and that it may increase any adverse events (RR 1.07, 95% CI 1.04–1.11, low certainty) and serious adverse events (RR 1.20, 95% CI 1.00–1.43, low certainty) compared with placebo [4].
What is Saxenda and who is it approved for?
Saxenda is liraglutide, a glucagon-like peptide 1 (GLP-1) receptor agonist given by subcutaneous injection. It was first approved in the United States in 2010 [1][6]. The pen is a 6 mg/mL solution in a 3 mL prefilled, single-patient-use device that delivers doses of 0.6 mg, 1.2 mg, 1.8 mg, 2.4 mg or 3 mg [1][6].
The FDA-approved indication is use alongside a reduced-calorie diet and increased physical activity to reduce excess body weight and maintain weight reduction long term, in [1][6]:
- Adults and pediatric patients aged 12 and older with a body weight greater than 60 kg and obesity
- Adults with overweight plus at least one weight-related comorbid condition
The label states two limitations of use: coadministration with other liraglutide-containing products or any other GLP-1 receptor agonist is not recommended, and safety and effectiveness have not been established in pediatric patients with type 2 diabetes [1][6]. The label was revised in February 2026 [1][6], and the DailyMed record was updated February 25, 2026 [1]. The packager listed on DailyMed is Novo Nordisk Pharmaceutical Industries, LP [1].
What are the most common side effects of Saxenda?
The prescribing information’s highlights section lists the most common adverse reactions, reported in 5% or more of patients, as: nausea, diarrhea, constipation, vomiting, injection site reactions, headache, hypoglycemia, dyspepsia, fatigue, dizziness, abdominal pain, increased lipase, upper abdominal pain, pyrexia and gastroenteritis [1][6]. That section groups these reactions under a single 5%-or-greater threshold and does not break out a separate percentage for each one.
In the 56-week SCALE Obesity and Prediabetes trial, the most frequently reported adverse events with liraglutide were mild or moderate nausea and diarrhea [2][3]. Serious adverse events occurred in 6.2% of the liraglutide group versus 5.0% of the placebo group [2][3]. The trial counted adverse events from the first dose until 14 days after the last dose [2].
The label directs anyone with a suspected adverse reaction to report it to Novo Nordisk at 1-844-363-4448 or to the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch [1][6].
How long does nausea from Saxenda last?
Nausea and diarrhea were the most frequently reported adverse events with liraglutide in the 56-week trial, and those events were mild or moderate in severity [2][3].
The trial used a step-up dosing schedule: patients started at 0.6 mg once daily and increased in weekly 0.6 mg increments until reaching 3.0 mg [2]. The label uses the same approach for standard prescribing: initiate at 0.6 mg per day for one week, then increase at weekly intervals until 3 mg is reached [1][6]. For pediatric patients, if an increased dose is not tolerated during escalation, the dose may be lowered back to the previous level, and escalation may take up to 8 weeks [1][6]. Any decision to change a dose schedule belongs with a prescriber.
What does the boxed warning about thyroid tumors say?
Saxenda’s label carries a boxed warning. It states that liraglutide causes dose-dependent and treatment-duration-dependent thyroid C-cell tumors at clinically relevant exposures in both sexes of rats and mice [6]. It is unknown whether Saxenda causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans, because the human relevance of the rodent findings has not been determined [1][6].
Because of this, Saxenda is contraindicated in people with a personal or family history of MTC and in people with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2) [1][6]. A separate contraindication covers hypersensitivity to liraglutide or any excipient in the product [1][6].
The label directs clinicians to counsel patients on symptoms of thyroid tumors: a mass in the neck, difficulty swallowing (dysphagia), difficulty breathing (dyspnea) and persistent hoarseness [6]. It also states that routine serum calcitonin monitoring or thyroid ultrasound is of uncertain value for early detection of MTC in patients treated with Saxenda [6].
What serious risks are listed in the label’s warnings?
Beyond the boxed warning, the prescribing information lists these warnings and precautions [1][6]:
- Acute pancreatitis (section 5.2): has been observed with GLP-1 receptor agonists, including Saxenda; discontinue if pancreatitis is suspected.
- Acute gallbladder disease (5.3): if gallstones (cholelithiasis) or gallbladder inflammation (cholecystitis) are suspected, gallbladder studies are indicated.
- Hypoglycemia (5.4): can occur in adults when Saxenda is used with an insulin secretagogue such as a sulfonylurea, or with insulin; the risk may be lowered by reducing the dose of those other drugs. Hypoglycemia also occurred in treated pediatric patients in the clinical trial even though those participants did not have type 2 diabetes; the label says to inform all patients of the risk and teach them the signs and symptoms.
- Heart rate increase (5.5): monitor heart rate at regular intervals.
- Acute kidney injury due to volume depletion (5.6): monitor renal function in patients reporting reactions that could lead to fluid loss.
- Severe gastrointestinal adverse reactions (5.7): use has been associated with gastrointestinal reactions, sometimes severe; Saxenda is not recommended in patients with severe gastroparesis.
- Hypersensitivity reactions (5.8): postmarketing reports include anaphylactic reactions and angioedema; discontinue and promptly seek medical advice.
- Pulmonary aspiration during general anesthesia or deep sedation (5.9): reported with GLP-1 receptor agonists in patients undergoing elective surgeries or procedures; patients should tell their healthcare providers about planned procedures.
Saxenda also delays gastric emptying, which may affect the absorption of oral medications taken with it; the label says to use such combinations with caution [1][6].
What did the independent Cochrane review find about side effects?
A 2025 Cochrane review pooled 24 randomized controlled trials with 9,937 participants, aged 31.3 to 64.7 years, with literature searches run on December 17, 2024. The review was funded by the World Health Organization [4].
Compared with placebo, liraglutide [4]:
| Outcome | Estimate | Studies / participants | Certainty |
|---|---|---|---|
| Any adverse events | RR 1.07 (95% CI 1.04–1.11) | 16 studies, 8,147 participants | Low |
| Serious adverse events | RR 1.20 (95% CI 1.00–1.43) | 20 studies, 8,487 participants | Low |
| Adverse events leading to withdrawal | RR 1.98 (95% CI 1.30–3.02) | 19 studies, 8,628 participants | Very low |
| Major adverse cardiovascular events (MACE) | RR 0.86 (95% CI 0.66–1.10) | 6 studies, 5,762 participants | Moderate |
| Mortality | RR 0.44 (95% CI 0.08–2.25) | 18 studies, 8,224 participants | Very low |
In plain terms, the review found liraglutide may increase any adverse events and serious adverse events, likely makes little to no difference in cardiovascular events, and leaves the mortality estimate very uncertain [4]. At long-term follow-up (104 to 162 weeks, 2 studies, 2,640 participants), serious adverse events showed RR 1.20 (95% CI 0.98–1.48) and withdrawal due to adverse events RR 2.16 (95% CI 1.59–2.93), both rated low certainty [4].
One caveat the reviewers flagged: 22 of the 24 included studies were funded by the drug manufacturer, with major manufacturer involvement in design, conduct, analysis or reporting in 13 of them [4].
How much weight did people lose in the main Saxenda trial?
The key trial is SCALE Obesity and Prediabetes (NCT01272219), a 56-week, double-blind study of 3,731 patients without type 2 diabetes who had a BMI of 30 or higher, or 27 or higher with treated or untreated dyslipidemia or hypertension [2][3].
Patients were randomized 2:1 to once-daily liraglutide 3.0 mg (2,487 patients) or placebo (1,244 patients); both groups received lifestyle-modification counseling [2][3]. At baseline, the mean age was 45.1 years, mean weight 106.2 kg, mean BMI 38.3; 78.5% were women and 61.2% had prediabetes [2][3].
| Outcome | Liraglutide 3.0 mg | Placebo |
|---|---|---|
| Mean weight loss | 8.4 kg | 2.8 kg |
| Difference vs placebo | −5.6 kg (95% CI −6.0 to −5.1), P<0.001 | — |
| Lost at least 5% of body weight | 63.2% | 27.1% |
| Lost more than 10% of body weight | 33.1% | 10.6% |
The weight-change analysis used last-observation-carried-forward imputation for missing values [2][3]. The trial was funded by Novo Nordisk, and the sponsor planned and performed the statistical analyses [2][3].
What does the pooled independent evidence say about weight loss?
The Cochrane review found that over the medium term (26 to 68 weeks), liraglutide versus placebo produced a mean difference in percentage weight change of −4.72% (95% CI −5.32 to −4.12), across 16 studies and 6,050 participants, rated very low certainty [4]. The clearer finding was the share of people reaching a meaningful threshold: achieving at least 5% weight reduction had RR 2.10 (95% CI 1.80–2.45) across 18 studies and 6,651 participants, rated moderate certainty [4].
At long-term follow-up (104 to 162 weeks, 2 studies, 1,262 participants), percentage weight change showed a mean difference of −4.34% (95% CI −5.26 to −3.43), low certainty, and achieving 5% weight reduction had RR 1.78 (95% CI 1.51–2.09), moderate certainty [4].
Quality of life, measured with the IWQOL-Lite-CT physical function scale, showed a mean difference of 2.90 (95% CI −0.08 to 5.89), moderate certainty, which the reviewers classified as little to no difference [4]. Their overall conclusion: liraglutide likely increases the proportion of people achieving at least 5% weight loss in the medium term, and that effect is likely sustained longer term, while the impact on percentage weight change, MACE, quality of life and mortality is limited or uncertain [4].
Has Saxenda been compared head to head with weekly semaglutide?
Yes, a head-to-head randomized trial exists. STEP 8, published in JAMA, compared weekly subcutaneous semaglutide with daily liraglutide in adults with overweight or obesity without diabetes, with outcomes assessed at week 68 [5].
The trial record cited for this comparison contains the trial’s design but no outcome figures, so no head-to-head weight-loss numbers from STEP 8 can be reported here. For context on the treatment landscape, five drugs are FDA-approved for long-term weight management in adults: orlistat, phentermine/topiramate, naltrexone/bupropion extended release, liraglutide and semaglutide [5].
How is Saxenda dosed and taken?
The recommended dose is 3 mg daily [1][6]. Treatment starts at 0.6 mg per day for one week, then the dose increases at weekly intervals until 3 mg is reached [1][6]. For pediatric patients who do not tolerate an increased dose during escalation, the dose may be lowered to the previous level, escalation may take up to 8 weeks, and patients not tolerating 3 mg daily may be reduced to 2.4 mg daily [1][6]. Adults with type 2 diabetes should monitor blood glucose before starting and during treatment [1][6].
The injection goes subcutaneously into the abdomen, thigh or upper arm, once daily, at any time of day, without regard to meal timing [1][6]. The full prescribing information includes storage and handling details in section 16 and a Medication Guide [6].
What happens to weight after stopping Saxenda?
The indication itself frames Saxenda as a long-term treatment: it is approved to reduce excess body weight and maintain weight reduction long term [1][6].
The discontinuation question was built into the pivotal trial. After week 56, liraglutide-treated patients who did not have prediabetes were re-randomized 1:1 to either continue liraglutide or switch to placebo for 12 weeks, specifically to assess whether efficacy was maintained after discontinuation of treatment and whether there were safety issues related to discontinuation [2].
The label directs patients to the Medication Guide and to section 17, Patient Counseling Information, for guidance on use [6].
Has the Saxenda label changed recently?
Yes, and some changes may explain why older articles describe the drug differently. According to the label’s Recent Major Changes section [1][6]:
- Indications and Usage (section 1) was revised in May 2025.
- Dosage and Administration, Patient Selection (2.1) was removed in May 2025.
- Contraindications, Pregnancy (section 4) was removed in May 2025.
- Warnings and Precautions, Severe Gastrointestinal Adverse Reactions (5.7) was added in October 2025.
- Suicidal Behavior and Ideation (5.9) was removed in February 2026.
Pregnancy is now addressed under Use in Specific Populations (8.1): Saxenda may cause fetal harm, and it should be discontinued when pregnancy is recognized [1][6].
Does Saxenda cause suicidal thoughts?
No causal link has been established. European and United States regulators have not confirmed a causal relationship between these drugs and suicidality [7]. A pharmacovigilance analysis of the European EudraVigilance database covering January 1, 2021 through December 31, 2025 included 42,941 eligible case reports for liraglutide, semaglutide and tirzepatide. Suicide or self-injury events numbered 37 for liraglutide, 141 for semaglutide and 47 for tirzepatide; compared with tirzepatide, the reporting frequency was higher for liraglutide (ROR 2.54, 95% CI 1.60–4.01) and semaglutide (ROR 2.69, 95% CI 1.91–3.83) [7].
The authors of that analysis state their findings do not establish causality, are a measure of reporting disproportionality only, and do not contradict regulatory conclusions [7]. Gastrointestinal disorders were the most frequent adverse events in the database overall [7]. Separately, the label’s Recent Major Changes section shows the Suicidal Behavior and Ideation warning was removed from the Saxenda label in February 2026 [1][6].
Sources
- DailyMed. SAXENDA (liraglutide) injection, solution drug label information. Updated February 25, 2026.
- New England Journal of Medicine. A randomized, controlled trial of 3.0 mg of liraglutide in weight management.
- PubMed. A randomized, controlled trial of 3.0 mg of liraglutide in weight management.
- PubMed. Liraglutide for adults living with obesity.
- JAMA. 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.
- Novo Nordisk. Saxenda (liraglutide) injection prescribing information.
- PubMed. Reporting patterns of suicide- and self-injury-related events involving liraglutide, semaglutide, and tirzepatide: data from the European pharmacovigilance database.
- PubMed. Gastroparesis induced by glucagon-like peptide-1 receptor agonists: a systematic review of clinical features, diagnosis, management, and outcomes.
- PubMed. GLP-1 receptor agonists and musculoskeletal outcomes: a systematic literature review and meta-analysis.
- Reddit. r/liraglutide discussion thread on dosing up to 3 mg.
- PubMed. A randomized, controlled trial of liraglutide for adolescents with obesity.
- US Food and Drug Administration. Drug shortage detail page for liraglutide injection.
Frequently asked questions
How common is nausea on Saxenda, and does it fade?
Nausea is among the label's most common adverse reactions, those reported in 5% or more of patients, though the cited highlights section does not give a percentage for each reaction. In the 56-week trial, nausea and diarrhea were the most frequent events with liraglutide and were mild or moderate. Neither the label nor the trial report states how long nausea typically lasts.
Is the thyroid tumor warning based on human data?
No. The boxed warning reflects dose-dependent and treatment-duration-dependent thyroid C-cell tumors seen in rats and mice at clinically relevant exposures. It is unknown whether Saxenda causes such tumors, including medullary thyroid carcinoma, in humans, because the human relevance of the rodent findings has not been determined.
Can you stay on a lower dose instead of going to 3 mg?
The label's recommended dose is 3 mg daily, reached by starting at 0.6 mg per day for one week and increasing weekly. The label's dose-reduction provisions apply to pediatric patients, who may drop back a step during escalation or settle at 2.4 mg daily if 3 mg is not tolerated. Dose decisions for any individual belong with a prescriber.
How much weight is typical in a year on Saxenda?
In the 56-week pivotal trial, the liraglutide 3 mg group lost an average of 8.4 kg versus 2.8 kg with placebo, a difference of −5.6 kg (95% CI −6.0 to −5.1). A total of 63.2% on liraglutide lost at least 5% of body weight, and 33.1% lost more than 10%.
How does Saxenda compare with weekly semaglutide?
A head-to-head randomized trial, STEP 8, compared weekly subcutaneous semaglutide with daily liraglutide in adults with overweight or obesity without diabetes, with outcomes assessed at week 68. The cited trial record contains the design but no outcome figures, so no head-to-head weight-loss numbers can be reported here.
What happens to weight after stopping Saxenda?
The pivotal trial was designed to examine this: after week 56, liraglutide patients without prediabetes at screening were re-randomized 1:1 to continue the drug or switch to placebo for 12 weeks, to assess whether efficacy was maintained after discontinuation. The approved indication frames Saxenda as long-term treatment to maintain weight reduction.
Is Saxenda safe in pregnancy?
The label states Saxenda may cause fetal harm and should be discontinued when pregnancy is recognized. A pregnancy contraindication was removed from the label in May 2025, and pregnancy is now addressed under Use in Specific Populations (8.1).
Does Saxenda cause suicidal thoughts?
No causal link has been established. EU and US regulators have not confirmed one. In a 2021–2025 EudraVigilance analysis of 42,941 eligible reports across liraglutide, semaglutide and tirzepatide, suicide or self-injury events numbered 37 for liraglutide, 141 for semaglutide and 47 for tirzepatide; the authors state this reflects reporting disproportionality, not causality. The Suicidal Behavior and Ideation warning was removed from the Saxenda label in February 2026.
This article summarizes FDA labeling, published research and company information current as of September 14, 2026. It is not medical advice and does not replace a conversation with your own healthcare provider. How we research and verify.