What the label lists and what reports show
Zilucoplan side effects
Zilucoplan's FDA label: “The most common adverse reactions (≥10%) in patients with gMG were injection site reactions, upper respiratory tract infection, and diarrhea.” FAERS holds 817 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 injection site pain (95 reports).
- No generic listed
- Boxed warning
Check it at the source: the zilucoplan FDA label on DailyMed (effective February 3, 2026, UCB, 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 ZILBRYSQ?ZILBRYSQ may cause serious side effects, including: See " What is the most important information I should know about ZILBRYSQ? " Inflammation of the pancreas (pancreatitis) and other pancreatic problems. Pancreatitis and pancreatic cysts have happened in people who use ZILBRYSQ. Your healthcare provider will do blood tests to check your pancreas before you start treatment with ZILBRYSQ. Call your healthcare provider right away if you have pain in your stomach area (abdomen) that will not go away. Your healthcare provider will tell you if you should stop using ZILBRYSQ. The pain may be severe or felt going from your abdomen to your back. The pain may happen with or without vomiting. These may be symptoms of pancreatitis. The most common side effects of ZILBRYSQ include: injection site reactions. upper respiratory tract infections. diarrhea. […]
Source: FDA drug label, NDA216834 (Ucb Inc), as published by UCB, Inc., effective February 3, 2026 (SPL set 9f1d53d6-e495-4a3a-8bb9-680a15d25034), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions (≥10%) in patients with gMG were injection site reactions, upper respiratory tract infection, and diarrhea.
Table 2: Adverse Reactions in at least 5% of Patients Treated with ZILBRYSQ and More Frequently than in Patients who Received Placebo in Study 1
| Adverse Reaction | ZILBRYSQ 0.3 mg/kg (n=86) % | Placebo (n=88) % |
|---|---|---|
| Injection site reactions | 29 | 16 |
| Upper respiratory tract infections | 14 | 7 |
| Diarrhea | 11 | 2 |
| Urinary tract infection | 8 | 5 |
| Nausea or vomiting | 8 | 7 |
| Lipase increased | 7 | 0 |
| Amylase increased | 5 | 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, continuedThe following clinically significant adverse reactions are discussed in greater detail in other sections of the labeling: Serious Meningococcal Infections [see Warnings and Precautions (5.1) ] Other Infections [see Warnings and Precautions (5.3) ] Pancreatitis and Other Pancreatic Conditions [see Warnings and Precautions (5.4) ] The most common adverse reactions (≥10%) in patients with gMG were injection site reactions, upper respiratory tract infection, and diarrhea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact UCB, Inc. at 844-599-2273 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. A total of 212 patients were treated with ZILBRYSQ 0.3 mg/kg in clinical studies in gMG. Of these, 137 patients were exposed for at least 6 months, and 87 were exposed for at least 1 year. In a placebo-controlled study (Study 1) in patients with gMG, 86 patients received ZILBRYSQ 0.3 mg/kg [see Clinical Studies (14) ]. Of these 86 patients, approximately 61% were female, 77% were White, 8% were Asian, and 8% were of Hispanic or Latino ethnicity. …
Source: FDA drug label, NDA216834 (Ucb Inc), as published by UCB, Inc., effective February 3, 2026 (SPL set 9f1d53d6-e495-4a3a-8bb9-680a15d25034), via openFDA; the full label on DailyMed
What do FAERS reports show?
817 reports list zilucoplan among the medicines taken, each a report of something that happened, not proof the medicine caused it; 40 are coded as a death and 329 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 18 reactions below, 4 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?
- Zilucoplan: 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