Welireg (Belzutifan)

Prescription medicineOnly Available By Prescription

What if I find a lower price with another pharmacy?

We guarantee the lowest price on all of our prescription products. If you find your medications cheaper at any other recognized licensed mail order pharmacy, we will not only match their price, we will beat it by 25% of the difference. It is our 125% price match guarantee!

Example: If you find a product on Canada Drugs Direct for $50.00 and find the same product for $40.00 at another mail order pharmacy, we will provide you with a $12.50 discount, bringing your total to $37.50.

To get the discount please make sure to mention the price match to the customer service team when they call to collect payment for your order. Or call toll free at 1-888-904-8467 to place the order through the phone.

Terms & Conditions of Program

  • Guaranteed lowest price is only valid at the time of sale.
  • We will only match the current advertised price.
  • Products must be identical and in stock at the time of placing an order with a licensed mail order pharmacy. They must be an online Canadian pharmacy with an address in Canada.
  • Products must be authentic in brand and size (same manufacturer, same country of manufacture, same pack size, same strength and same quantity).
  • Products must be new. We cannot match the price of any used, short expiry or expired product.
  • Price match can only be issued over the phone with our customer service team. Please note at this time we cannot offer price matching for the products Ozempic or Saxenda.
What is a Generic Drug?

A generic drug is a copy of the brand-name drug with the same dosage, safety, strength, quality, consumption method, performance, and intended use. Before generics become available on the market, the generic company must prove it has the same active ingredients as the brand-name drug and works in the same way and in the same amount of time in the body.

The only differences between generics and their brand-name counterparts is that generics are less expensive and may look slightly different (eg. different shape or color), as trademarks laws prevent a generic from looking exactly like the brand-name drug.

Generics are less expensive because generic manufacturers don't have to invest large sums of money to develop a drug. When the brand-name patent expires, generic companies can manufacture a copy of the brand-name and sell it at a substantial discount.


Welireg is a prescription medication that treats von Hippel-Lindau (VHL) disease in people with hemangioblastomas, renal cell carcinoma (RCC), or pancreatic neuroendocrine tumors (pNET).

Welireg works by inhibiting the activity of hypoxia-inducible factor-2 alpha (HIF-2a), a protein that plays a key role in promoting tumor growth. By blocking HIF-2a, Belzutifan helps to suppress the formation and progression of renal cell carcinoma.

Fact Table




US DailyMed


No Data Available

Legal status


Chemical Name


Elimination half-life

14 hours

Dosage (Strength)



Consult Doctor



Protein binding


PubChem CID





No Data Available

ATC code






Routes of administration

By mouth


The usual dosage is 120 mg by mouth once daily, with or without food. Welireg is available as 40 mg tablets.


The active ingredient in Welireg is belzutifan.


Common drug-drug interactions may include:

  • Acetohexamide
  • Acarbose
  • Albiglutide
  • Alogliptin
  • Atogepant
  • Bexagliflozin
  • Canagliflozin
  • CarBAMazepine
  • Chlorpropamide
  • CloZAPine
  • CYP2C19 Inhibitors
  • CYP3A4 Inducers
  • Dapagliflozin
  • Dipeptidyl Peptidase-4 (DPP-4) Inhibitors
  • Dulaglutide
  • Empagliflozin
  • Ertugliflozin
  • Exenatide
  • First Generation Sulfonylureas
  • Gliclazide
  • Glimepiride
  • Glipizide
  • Glyburide (Glibenclamide)
  • Glucagon-Like Peptide-1 (GLP-1) Analogues
  • Hormonal Contraceptives
  • Incretin-Based Drugs
  • Linagliptin
  • Liraglutide
  • Lixisenatide
  • Metformin
  • Metiglinide Analogues
  • Miglitol
  • Nateglinide
  • NiMODipine
  • Pioglitazone
  • Pramlintide
  • Repaglinide
  • Rosiglitazone
  • Saxagliptin
  • Second Generation Sulfonylureas
  • Selpercatinib
  • Semaglutide
  • Sodium-Glucose Cotransporter-2 (SGLT2) Inhibitors
  • Sirolimus
  • Sitagliptin
  • Tacrolimus
  • Teplizumab
  • Thiazolidinediones
  • Tirzepatide
  • Tolazamide
  • Tolbutamide
  • Troglitazone
  • Ubrogepant


Your healthcare provider should monitor for symptoms of anemia during treatment. Monitoring may include watching for symptoms and checking blood labs. If anemia occurs, Welireg may need to be discontinued.

Oxygen saturation should be monitored before and during treatment with Welireg. If low oxygen (hypoxia) occurs, Welireg should be temporarily stopped. For life-threatening hypoxia, Welireg should be discontinued.

There are many potential drug-drug interactions with this medication. Tell your doctor about everything you are taking before starting this drug.

Side Effects

The most common adverse effects are:

  • Abdominal pain
  • Anemia
  • Arthralgia
  • Constipation
  • Cough
  • Decreased calcium
  • Decreased phosphate
  • Dehydration
  • Dizziness
  • Dyspnea
  • Edema
  • Fatigue
  • Flu-like symptoms
  • Headache
  • Hypertension
  • Hypoxia
  • Increased creatinine
  • Increased aspartate aminotransferase
  • Leukocytosis
  • Musculoskeletal pain
  • Myalgia
  • Nausea
  • Retinal detachment
  • Retinal vein occlusion
  • Upper respiratory tract infection
  • Visual impairment
  • Vomiting
  • Weight gain


Welireg [package insert]. Whitehouse Station, NJ: Merck; 2021.

IMPORTANT NOTE: The above information is intended to increase awareness of health information and does not suggest treatment or diagnosis. This information is not a substitute for individual medical attention and should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. See your health care professional for medical advice and treatment.

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