What the label lists and what reports show
Ravulizumab side effects
Ravulizumab's FDA label: “Most common adverse reactions in patients with PNH (incidence ≥ 10%) were upper respiratory tract infection and headache.” FAERS holds 13,435 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 fatigue (1,777 reports).
- No generic listed
- Boxed warning
Check it at the source: the ravulizumab FDA label on DailyMed (effective October 9, 2025); 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 ULTOMIRIS?ULTOMIRIS can cause serious side effects including: See " What is the most important information I should know about ULTOMIRIS? " Infusion-related reactions. Infusion-related reactions may happen during your ULTOMIRIS treatment. Symptoms of an infusion-related reaction with ULTOMIRIS may include lower back pain, stomach (abdominal) pain, muscle spasms, changes in blood pressure, tiredness, feeling faint, shaking chills (rigors), discomfort in your arms or legs, or bad taste. […]
Source: FDA drug label, Alexion Pharmaceuticals Inc., effective October 9, 2025 (SPL set a9a590d9-0217-43c7-908d-e62a71279791), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions in patients with PNH (incidence ≥ 10%) were upper respiratory tract infection and headache.
Table 13: Adverse Reactions Reported in ≥ 5% in ULTOMIRIS-Treated Adult Patients with NMOSD in Study ALXN1210-NMO-307
| Body System Adverse Reaction | ULTOMIRIS (N=58) n (%) Blood and Lymphatic System Disorder |
|---|---|
| Lymphadenopathy | 3 (5) |
| Constipation | 4 (7) |
| Vomiting | 4 (7) |
| Diarrhea | 3 (5) |
| Gastroesophageal reflux disease | 3 (5) |
| Pyrexia | 5 (9) |
| Chills | 3 (5) |
| Fatigue | 3 (5) |
| Malaise | 3 (5) |
| Non-cardiac chest pain | 3 (5) |
| Vaccination site pain | 3 (5) |
| COVID-19 | 14 (24) |
| Urinary tract infection | 6 (10) |
| Cystitis | 5 (9) |
| Upper respiratory tract infection | 5 (9) |
| Nasopharyngitis | 3 (5) |
| Sinusitis | 3 (5) |
| Infusion related reaction | 4 (7) |
| Back pain | 7 (12) |
| Arthralgia | 6 (10) |
| Myalgia | 3 (5) |
| Headache | 14 (24) |
| Dizziness | 4 (7) |
| Migraine | 3 (5) |
| Cough | 3 (5) |
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) ] Infusion-Related Reactions [see Warnings and Precautions (5.6) ] Most common adverse reactions in patients with PNH (incidence ≥ 10%) were upper respiratory tract infection and headache. ( 6.1 ) Most common adverse reactions in patients with aHUS (incidence ≥ 20%) were upper respiratory tract infection, diarrhea, nausea, vomiting, headache, hypertension, and pyrexia. ( 6.1 ) Most common adverse reactions in adult patients with gMG (incidence ≥ 10%) were diarrhea and upper respiratory tract infection. ( 6.1 ) Most common adverse reactions in adult patients with NMOSD (incidence ≥ 10%) were COVID-19, headache, back pain, arthralgia, and urinary tract infection. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Alexion Pharmaceuticals, Inc. at 1-844-259-6783 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trial 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.
Source: FDA drug label, Alexion Pharmaceuticals Inc., effective October 9, 2025 (SPL set a9a590d9-0217-43c7-908d-e62a71279791), via openFDA; the full label on DailyMed
What do FAERS reports show?
13,435 reports list ravulizumab among the medicines taken, each a report of something that happened, not proof the medicine caused it; 941 are coded as a death and 2,634 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. Reports rose sharply in 2024 (4,318, against a median of 434 a year): FAERS counts follow reporting, which news, litigation and label changes can drive, not how often a reaction happens. Of the 20 reactions below, 10 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?
- Ravulizumab: 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