What the label lists and what reports show
Naloxegol side effects
Naloxegol's FDA label: “The most common adverse reactions in clinical trials (≥3%) are: abdominal pain, diarrhea, nausea, flatulence, vomiting, and headache.” FAERS holds 3,902 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is diarrhoea (380 reports).
- No generic listed
Check it at the source: the naloxegol FDA label on DailyMed (effective September 1, 2026, Averitas Pharma, Inc.); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of MOVANTIK?See “What is the most important information I should know about MOVANTIK?” The most common side effects of MOVANTIK include: stomach (abdomen) pain, diarrhea, nausea, gas, vomiting, and headache. Tell your healthcare provider if you have any side effect that bothers you or that does not go away. These are not all the possible side effects of MOVANTIK. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Source: FDA drug label, Averitas Pharma, Inc., effective September 1, 2026 (SPL set 28596788-b73f-4247-85fc-3105f51fff5a), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions in clinical trials (≥3%) are: abdominal pain, diarrhea, nausea, flatulence, vomiting, and headache.
Table 1. Adverse Reactions Adverse reactions occurring in ≥3% of patients receiving MOVANTIK 12.5 mg or 25 mg and at an incidence greater than placebo. in Patients with OIC and Non-Cancer Pain (Studies 1 and 2)
| Adverse Reaction | MOVANTIK 25 mg (n=446) | MOVANTIK 12.5 mg (n=441) | Placebo (n=444) |
|---|---|---|---|
| Abdominal Pain Includes: abdominal pain, abdominal pain upper, abdominal pain lower, and… | 21% | 12% | 7% |
| Diarrhea | 9% | 6% | 5% |
| Nausea | 8% | 7% | 5% |
| Flatulence | 6% | 3% | 3% |
| Vomiting | 5% | 3% | 4% |
| Headache | 4% | 4% | 3% |
| Hyperhidrosis | 3% | <1% | <1% |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedSerious and important adverse reactions described elsewhere in labeling include: Opioid withdrawal [see Warnings and Precautions (5.1) ] Severe abdominal pain and/or diarrhea [see Warnings and Precautions (5.2) ] Gastrointestinal perforation [see Warnings and Precautions (5.3) ] The most common adverse reactions in clinical trials (≥3%) are: abdominal pain, diarrhea, nausea, flatulence, vomiting, and headache. (6.1) To report SUSPECTED ADVERSE REACTIONS, contact Averitas Pharma at 1-877-900-6479 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The data described below reflect exposure to MOVANTIK in 1497 patients in clinical trials, including 537 patients exposed for greater than six months, and 320 patients exposed for 12 months. The safety data described in Table 1 are derived from two double-blind, placebo-controlled trials (Studies 1 and 2) in patients with OIC and non-cancer related pain [see Clinical Studies (14) ]. Study 3 (n=302) was a safety extension study that allowed patients from Study 1 to continue the same blinded treatment for an additional 12 weeks. …
Source: FDA drug label, Averitas Pharma, Inc., effective September 1, 2026 (SPL set 28596788-b73f-4247-85fc-3105f51fff5a), via openFDA; the full label on DailyMed
What do FAERS reports show?
3,902 reports list naloxegol among the medicines taken, each a report of something that happened, not proof the medicine caused it; 286 are coded as a death and 890 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 20 reactions below, 9 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Naloxegol: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions