COLAZAL vs WELIREG

Independent side-by-side comparison.

Rated against independent regulatory sources·Last updated October 9, 2026·How we rate

Possible drug interaction. COLAZAL and WELIREG are different prescription medicines. Combining or switching between them can cause interactions — talk to a pharmacist or prescriber before making changes. This page is not medical advice.

Attribute	COLAZAL	WELIREG
Rating	74/100	72/100
Pharmacy pays	~$11.02 /30	—
Type	RX	RX
Active ingredient	BALSALAZIDE DISODIUM	BELZUTIFAN
Manufacturer	Valeant Pharm Intl	Merck Sharp Dohme
Dosage forms	Capsule	Tablet
Drug class	Aminosalicylate	—
Boxed warning	None	Boxed warning
Treats	Ulcerative Colitis	Von Hippel-Lindau Disease

colazal welireg

Rating

74/100

72/100

Pharmacy pays

~$11.02 /30

—

Type

Active ingredient

BALSALAZIDE DISODIUM

BELZUTIFAN

Manufacturer

Valeant Pharm Intl

Merck Sharp Dohme

Dosage forms

Capsule

Tablet

Drug class

Aminosalicylate

—

Boxed warning

None

Boxed warning

Treats

Ulcerative Colitis

Von Hippel-Lindau Disease

Frequently asked questions

Which is better-rated, Colazal or Welireg?

By our independent rating, Colazal scores higher — 3.7 vs 3.6 out of 5 for Welireg. Ratings are based on FDA regulatory (recall-safety) data.

What is the difference between Colazal and Welireg?

Colazal contains Balsalazide Disodium, while Welireg contains Belzutifan — they have different active ingredients.

Ratings are based on FDA regulatory (recall-safety) data. This comparison is for general reference only — not medical advice. Always consult a licensed professional before choosing or switching a medication.