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Generic name: colesevelamKOE-le-SEV-e-lam ]
Drug class: Bile acid sequestrants

Medically reviewed by on Sep 14, 2023. Written by Cerner Multum.

What is Welchol?

Welchol lowers "bad" cholesterol in the blood, which is also called LDL (low-density lipoprotein) cholesterol. Lowering your LDL cholesterol may reduce your risk of hardened arteries, which can lead to heart attacks, stroke, and circulation problems.

Welchol is used to treat high cholesterol in adults and children at least 10 years old.

Welchol is sometimes used together with "statin" cholesterol medications such as atorvastatin, lovastatin, simvastatin, Crestor, Lipitor, Pravachol, Zocor, and others.

Welchol is also used to improve blood sugar control in adults with type 2 diabetes mellitus. This medication is not for treating type 1 diabetes.

Welchol may also be used for purposes not listed in this medication guide.

Welchol side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Welchol may cause serious side effects. Stop using Welchol and call your doctor at once if you have:

Common side effects of Welchol may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


You should not take Welchol if you have diabetic ketoacidosis, very high triglycerides, a history of bowel obstruction, or a history of pancreatitis caused by high triglycerides.

Before taking this medicine

You should not take Welchol if you are allergic to it, or if you have:

Welchol may increase your triglycerides, which can increase your risk of pancreatitis (inflammation of the pancreas). Your doctor will perform blood tests to make sure your triglycerides are not too high for you to safely use this medicine.

Welchol is not for use in girls who have not yet started having menstrual periods.

Welchol should not be given to a child younger than 10 years old.

Tell your doctor if you have ever had:

Tell your doctor if you are pregnant or if you become pregnant.

The powder form of colesevelam may contain phenylalanine. Tell your doctor if you have phenylketonuria (PKU).

How should I take Welchol?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Take Welchol with a meal and a full glass of water or other liquid.

You may have to take several tablets at a time each time you take Welchol. Tell your doctor if you have trouble swallowing the tablet whole.

Welchol powder must be mixed with 8 ounces of water, fruit juice, or a diet soft drink. Stir and drink this mixture right away. Add a little more water to the glass, swirl gently and drink right away.

Do not change the dose or timing of any other cholesterol or diabetes medications without your doctor's advice.

You will need frequent blood tests.

Welchol is only part of a complete treatment program that may also include diet, exercise, and weight control. You may need to follow a special diet to prevent constipation while using this medicine. Follow all instructions of your doctor or dietitian.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the medicine (with food and a full glass of water) as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking Welchol?

Avoid eating foods high in fat or cholesterol, or Welchol will not be as effective.

What other drugs will affect Welchol?

Welchol can make it harder for your body to absorb other medicines you take, which could make those medicines less effective. If you take any of the following medicines, take them 4 hours before you take this medicine:

This list is not complete and many other drugs may affect Welchol. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

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