Most common side effects in the label
The label’s adult table lists reactions in at least 2% of people on Saxenda® and more often than on placebo. The rows below are those at 5% or more; the full table continues in the label [1].
In the adult trials, about 68% on Saxenda® and 39% on placebo reported digestive disorders. The label says most episodes were mild or moderate, the share of people reporting nausea declined as treatment continued, and 6.2% vs 0.8% stopped because of digestive reactions [1].
| Adverse reaction | Placebo (N=1941) % | Saxenda® (N=3384) % |
|---|---|---|
| Nausea | 13.8 | 39.3 |
| Diarrhea | 9.9 | 20.9 |
| Constipation | 8.5 | 19.4 |
| Vomiting | 3.9 | 15.7 |
| Injection site reaction | 10.5 | 13.9 |
| Headache | 12.6 | 13.6 |
| Hypoglycemia in type 2 diabetes | 6.6 | 12.6 |
| Dyspepsia | 2.7 | 9.6 |
| Fatigue | 4.6 | 7.5 |
| Dizziness | 5 | 6.9 |
| Abdominal pain | 3.1 | 5.4 |
| Increased lipase | 2.2 | 5.3 |
| Upper abdominal pain | 2.7 | 5.1 |
A reaction makes it into the label table only when at least 2% of people taking the medicine reported it and placebo users reported it less often; the placebo column shows how often the same complaint was reported without the medicine. The label also says these rates cannot be compared directly with other medicines’ trials [1]. The European Union product information (SmPC and package leaflet) is published by EMA [2]; local leaflets can differ in detail.
Serious side effects the label warns about
Saxenda® carries a boxed warning: in rodents, the active ingredient caused thyroid C-cell tumors, and it is not known whether this happens in humans. The label rules it out for anyone who has had medullary thyroid carcinoma (MTC), or whose close family has, and for people with MEN 2 (a hereditary endocrine tumour syndrome). Section 6 of the label lists these serious adverse reactions [1]:
- Risk of thyroid C-cell tumors (the boxed warning)
- Acute pancreatitis
- Acute gallbladder disease
- Low blood sugar (hypoglycemia), with a higher risk alongside insulin or sulfonylurea-type medicines
- Heart rate increase
- Acute kidney injury due to fluid loss (volume depletion)
- Severe gastrointestinal adverse reactions
- Hypersensitivity (allergic) reactions
- Food or liquid entering the lungs (pulmonary aspiration) under general anesthesia or deep sedation
What changed in the label in 2026
The “Recent Major Changes” section of the February 2026 label lists the former warning on suicidal behavior and ideation as removed in February 2026. Mood changes that worry you remain a topic for your clinician. [1]
What happens if I stop Saxenda®?
The label does not describe what happens to side effects or weight after stopping [1], and we did not find a Saxenda® withdrawal trial among the sources checked for this page.
Stopping, pausing or restarting is a decision to make with your prescriber.
Saxenda®, pregnancy and birth control
The label says to stop Saxenda® when a pregnancy is recognized, because weight loss offers no benefit in pregnancy and may harm the baby [1]. Its “Recent Major Changes” section lists the former pregnancy contraindication as removed in May 2025, replaced by this guidance [1].
Plans for pregnancy or breastfeeding are worth raising with your prescriber before they happen.
Should I mention Saxenda® before surgery or sedation?
Yes, according to the label. It describes rare postmarketing reports of food or liquid getting into the lungs (pulmonary aspiration) under general anesthesia or deep sedation in people taking GLP-1 receptor agonists, even when they had followed fasting instructions. The label says the data are not enough to recommend whether to change fasting or pause the medicine, and asks patients to tell their healthcare providers before any planned surgery or procedure [1].
Can I drink alcohol while taking Saxenda®?
The Saxenda® label does not mention drinking alcohol [1]. Two related facts come from general medical sources: heavy alcohol use is one of the most common causes of pancreatitis [3], which the label lists as a serious risk [1]; and drinking too much alcohol without enough food can cause low blood sugar in people with diabetes [4]. How alcohol fits with your treatment is a question for your prescriber.
Is hair loss listed for Saxenda®?
Hair loss is not in the Saxenda® clinical-trial tables. “Alopecia” (hair loss) appears in the label’s postmarketing section, which lists reports from a population of uncertain size, so neither how often it happens nor whether the medicine caused it can be reliably established [1].
For background, MedlinePlus describes a usually temporary kind of shedding (telogen effluvium) that can follow major physical stress, illness, surgery or crash diets [7]. A dermatologist or your prescriber can look at the cause.
Is burping listed for Saxenda®?
The label lists belching (eructation) among the adult table: 4.5% on Saxenda® vs 0.2% on placebo [1]. It does not describe the smell, so “sulfur burps” as such are not a label term; if burping comes with heartburn, vomiting or stomach pain that will not go away, the table below says who to contact.
Saxenda® is a trademark of Novo Nordisk. PepLabo is not affiliated with this company. This page is not medical advice; percentages come from clinical-trial tables in the label and do not predict what you will experience.
When to get help
| Sign | Who to contact | How fast | Source |
|---|---|---|---|
| Swelling of the lips, tongue, face or throat, struggling to breathe or swallow, fainting or a racing pulse | Emergency services. According to the guide, Saxenda® should be stopped and urgent medical help sought. | Emergency | Saxenda® Medication Guide [1]; MedlinePlus [6] |
| Belly pain that is severe and does not ease, whether or not you vomit; it can reach through to the back | Your healthcare provider right away; the guide says to stop using Saxenda®. If you cannot reach them, urgent care. | Emergency | Saxenda® Medication Guide [1]; NIDDK [3] |
| Ongoing nausea, vomiting or diarrhea, or dehydration signs such as feeling very thirsty, a dry mouth, urinating less than usual, dark urine or dizziness | Your healthcare provider, right away: fluid loss can lead to kidney problems. | Today | Saxenda® Medication Guide [1]; MedlinePlus [5] |
| Pain in the upper stomach, fever, yellowing of the skin or eyes, or clay-colored stools | Your healthcare provider (gallbladder problems). | Today | Saxenda® Medication Guide [1] |
| Shakiness, sweating, confusion, blurred vision or a fast heartbeat; the risk is higher alongside insulin or a sulfonylurea | Follow the low-blood-sugar plan from your healthcare provider; the guide asks you to discuss it before starting. | Today | Saxenda® Medication Guide [1]; MedlinePlus [4] |
| A new neck lump or swelling, a hoarse voice, difficulty swallowing or breathlessness | Your healthcare provider (thyroid section of the guide). | Today | Saxenda® Medication Guide [1] |
| A racing or pounding heart at rest that lasts several minutes | Your healthcare provider. | Today | Saxenda® Medication Guide [1] |
| A planned surgery or a procedure with anesthesia or deep sedation | Tell every healthcare provider involved that you use this medicine, before the procedure. | At your next appointment | Saxenda® Medication Guide [1] |
| Mild nausea, constipation, heartburn or other common side effects that you can manage | Mention them at your next appointment; a dated log helps. | At your next appointment | Common reactions: label section 6 [1] |
