What the label lists and what reports show

Omaveloxolone side effects

Omaveloxolone's FDA label: “Most common adverse reactions (incidence ≥20% and greater than placebo) are elevated liver enzymes (AST/ALT), headache, nausea, abdominal pain, fatigue, diarrhea, and musculoskeletal pain.” FAERS holds 1,695 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 (152 reports).

No generic listed

Check it at the source: the omaveloxolone FDA label on DailyMed (effective April 6, 2026, Biogen); 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 SKYCLARYS?
SKYCLARYS may cause serious side effects, including: increase in blood liver enzymes. Some people taking SKYCLARYS have had an increase in the level of liver enzymes in their blood. Your healthcare provider will do liver function tests before you start taking SKYCLARYS every month for the first 3 months after starting your treatment with SKYCLARYS during certain times as needed while taking SKYCLARYS If your liver enzymes increase, your healthcare provider may change your dose during treatment, stop treatment for some time, or completely stop treatment with SKYCLARYS. increase in a blood protein called B-Type Natriuretic Peptide (BNP). BNP tells how well your heart is working. Your healthcare provider will check your BNP levels before your treatment with SKYCLARYS. […]

Source: FDA drug label, Biogen, effective April 6, 2026 (SPL set 2709e870-df3d-f30f-e063-6394a90aeda1), via openFDA; the full label on DailyMed

What does the label list?

From the label: adverse reactions
Most common adverse reactions (incidence ≥20% and greater than placebo) are elevated liver enzymes (AST/ALT), headache, nausea, abdominal pain, fatigue, diarrhea, and musculoskeletal pain.

Table 3: Adverse Reactions Reported in 10% or More of Patients Treated with SKYCLARYS and Greater than Placebo (Study 1)

Adverse Reactions	SKYCLARYS 150 mg (N = 51) %	Placebo (N = 52) %
Elevated liver enzymes (AST/ALT)	37	2
Headache	37	25
Nausea	33	13
Abdominal pain	29	6
Fatigue	24	14
Diarrhea	20	10
Musculoskeletal pain	20	15
Oropharyngeal pain	18	6
Influenza	16	6
Vomiting	16	12
Muscle spasms	14	6
Back pain	13	8
Decreased appetite	12	4
Rash	10	4

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, continued
The following clinically significant adverse reactions are described in greater detail in other labeling sections: Elevation of aminotransferases [see Warnings and Precautions ( 5.1 )] Elevation of BNP [see Warnings and Precautions ( 5.2 )] Lipid abnormalities [see Warnings and Precautions ( 5.3 )] Most common adverse reactions (incidence ≥20% and greater than placebo) are elevated liver enzymes (AST/ALT), headache, nausea, abdominal pain, fatigue, diarrhea, and musculoskeletal pain. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Biogen at 1-844-987-3224- 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 with rates in clinical trials of another drug and may not reflect the rates observed in clinical practice. The safety of SKYCLARYS 150 mg once daily has been evaluated in 165 patients with Friedreich's ataxia, including 137 patients exposed for at least 48 weeks, and 125 patients exposed for at least 96 weeks. The most common adverse reactions in Study 1 (≥20% and greater than placebo) were elevated liver enzymes (AST/ALT), headache, nausea, abdominal pain, fatigue, diarrhea, and musculoskeletal pain. …

Source: FDA drug label, Biogen, effective April 6, 2026 (SPL set 2709e870-df3d-f30f-e063-6394a90aeda1), via openFDA; the full label on DailyMed

What do FAERS reports show?

1,695 reports list omaveloxolone among the medicines taken, each a report of something that happened, not proof the medicine caused it; 80 are coded as a death and 428 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 22 reactions below, 7 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

Fatigue (named in the label)152
Nausea (named in the label)124
Hepatic Enzyme Increased123
Product Dose Omission Issue (a use or a product term, not a reaction)106
Headache (named in the label)100
Diarrhoea (named in the label)92
Blood Cholesterol Increased82
Muscle Spasms (named in the label)75
Fall70
Atrial Fibrillation65
Alanine Aminotransferase Increased64
Urinary Tract Infection61
Abdominal Pain Upper57
Vomiting (named in the label)56
Death (an outcome recorded in the report)53
Friedreich^S Ataxia52
Asthenia49
Myalgia44
Dizziness43
Aspartate Aminotransferase Increased41
Drug Ineffective (a use or a product term, not a reaction)41
Pain41
Abdominal Discomfort40
Decreased Appetite (named in the label)40
Constipation38

Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms

What next?

Omaveloxolone: 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