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Belzutifan Side Effects

Medically reviewed by Last updated on Jun 1, 2023.

Applies to belzutifan: oral tablet.


Oral route (Tablet)

Warning: Embryo-fetal toxicityExposure to belzutifan during pregnancy can cause embryo-fetal harm.Verify pregnancy status prior to the initiation of belzutifan.Advise patients of these risks and the need for effective non-hormonal contraception. Belzutifan can render some hormonal contraceptives ineffective.

Serious side effects of Belzutifan

Along with its needed effects, belzutifan may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking belzutifan:

More common

Other side effects of Belzutifan

Some side effects of belzutifan may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

For Healthcare Professionals

Applies to belzutifan: oral tablet.


The most common adverse reactions, including laboratory abnormalities, that occurred during treatment with this drug were anemia, decreased hemoglobin, fatigue, increased creatinine, dizziness, headache, increased glucose, and nausea.[Ref]


Very common (10% or more): Hypertension (up to 16%)[Ref]


Very common (10% or more): Nausea (up to 36%), constipation (up to 21%), abdominal pain (up to 18%), diarrhea (15%)[Ref]


Very common (10% or more): Anemia (90%)[Ref]


Very common (10% or more): increased weight (up to 16%)[Ref]


Very common (10% or more): Myalgia (up to 25%), arthralgia (up to 21%), back pain (13%)[Ref]

Nervous system

Very common (10% or more): Headache (up to 44%), dizziness (up to 44%)[Ref]


Very common (10% or more): Visual impairment (including blurred vision, central retinal vein occlusion, and retinal detachment) (up to 21%)[Ref]


Very common (10% or more): Fatigue (up to 70%), peripheral edema (13%), Urinary tract infection (18%), upper respiratory tract infection (including bronchitis, sinusitis, viral upper respiratory infection) (up to 21%), increased creatinine (64%), increased glucose (34%), increased ALT (20%), increased AST (16%), decreased hemoglobin (93%), decreased leukocytes (11%)

Common (1% to 10%): Decreased corrected calcium, decreased phosphate[Ref]


Very common (10% or more): Insomnia (13%), anxiety (11%)[Ref]


Very common (10% or more): Dyspnea (up to 23%)[Ref]


1. (2022) "Product Information. Welireg (belzutifan)." Merck Sharp & Dohme LLC

2. (2022) "Product Information. Welireg (belzutifan)." Merck Sharp & Dohme (Australia) Pty Ltd

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.