Welchol (colesevelam) is a brand-name prescription medication. The Food and Drug Administration (FDA) has approved it to:

Here are some fast facts about Welchol:

  • Active ingredient: colesevelam
  • Drug class: bile acid sequestrant
  • Drug forms:
    • oral tablet
    • powder used to form an oral suspension

If Welchol works for your condition, your doctor will likely recommend you take it long-term.

As with other drugs, Welchol can cause side effects. Read on to learn about potential common, mild, and serious side effects. For a general overview of Welchol, including details about its uses, see this article.

* For this use, your doctor will only prescribe Welchol if you’ve tried diet and exercise that hasn’t worked to decrease your LDL.

Welchol can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took Welchol in clinical trials:

* For more information about this side effect, see “Side effect specifics” below.

Mild side effects can occur with Welchol use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Welchol’s prescribing information.

Mild side effects that have been reported with Welchol include:

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you develop a side effect while taking Welchol and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Side effect specifics” below.

Welchol may cause serious side effects. However, serious side effects from this medication are not common. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Welchol’s prescribing information.

If you develop serious side effects while taking Welchol, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported and their symptoms include:

* For more information about this side effect, see the “Side effect specifics” section below.
† An allergic reaction is possible after taking Welchol. However, it’s not clear whether this side effect occurred in clinical trials.

Welchol is approved to reduce low-density lipoprotein (LDL) cholesterol levels in children ages 10 to 17 years old. This is only for children with heterozygous familial hypercholesterolemia.

In clinical trials of Welchol, adults and children experienced similar side effects. However, the following symptoms were more common with children:

  • headache
  • vomiting
  • the common cold
  • increased blood levels of creatine phosphokinase (a type of protein)

If you’re concerned about side effects that your child may experience from taking Welchol, talk with their doctor.

Welchol may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

How do side effects of the Welchol powder and 625-mg tablet forms compare?

The side effects of the Welchol powder and the Welchol tablets should be similar. This is because both drug forms contain the same active ingredient, colesevelam. So, the side effects of both forms are likely the same.

If you have questions about Welchol’s drug forms and their side effects, talk with your doctor or pharmacist.

Do Welchol and its generic version have the same side effects?

Yes, Welchol and its generic version, colesevelam, have the same side effects. This is because both drugs contain the same active ingredient. So, they work in the same way to treat your condition.

In most cases, the generic version of a drug will be cheaper than the brand-name form. If you have questions about using colesevelam or Welchol, talk with your doctor or pharmacist.

Does Welchol cause memory loss?

No, Welchol is not known to cause memory loss. This side effect was not reported in clinical trials of the drug.

However, memory loss may be linked to other drugs that are prescribed to lower cholesterol levels. These include certain statin drugs, such as Lipitor (atorvastatin).

In addition, certain conditions, such as diabetes, may increase your risk of memory loss.

If you notice memory loss during your treatment with Welchol, talk with your doctor. They can help determine what’s causing your memory loss and the best treatment options for you.

Should I expect weight loss with Welchol?

It’s possible to experience weight changes, such as weight loss or weight gain, from your Welchol treatment. Weight changes were not commonly reported side effects in clinical trials of the drug.

In clinical trials, people reported weight changes between a loss of 0.6 kilograms (kg), about 1.3 pounds (lb), to a gain of 0.8 kg, about 1.8 lb. (One kg is about 2.2 lb.)

If you notice weight changes from your Welchol treatment, especially if they’re unexpected, tell your doctor. They can help determine what may be causing the changes in your weight.

Learn more about some of the side effects that Welchol may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Welchol.

Vitamin deficiency

It’s possible for Welchol to cause vitamin deficiencies (lower levels of vitamins than usual in your body). Specifically, Welchol can cause deficiencies in fat-soluble vitamins, such as vitamin A, D, E, or K. This side effect was not reported in Welchol’s clinical trials. However, it can still occur based on how the drug works in your body.

Vitamin deficiencies do not usually cause any symptoms. But, if vitamin deficiencies last a long time or are severe, you may experience the following symptoms:

  • bleeding or bruising easier than usual
  • nosebleeds
  • fatigue
  • weakness
  • hair loss
  • joint pain

You may have an increased risk of this side effect if you take Coumadin (warfarin), a blood thinner. And you may have a higher risk of vitamin deficiency if you have any malabsorption syndromes (conditions that decrease your absorption of nutrients).

If you have a vitamin K deficiency or have an increased risk of developing a vitamin K deficiency, tell your doctor. Taking Welchol can increase the risk of developing this condition even further.

What you can do

If you notice any symptoms of vitamin deficiency, tell your doctor. They can check your vitamin levels and confirm if you have a deficiency. Then, they’ll be able to prescribe you vitamin supplements to treat your condition.

To help prevent vitamin deficiencies, you should take your vitamins at least 4 hours before your Welchol dose.

Constipation

It’s possible to develop constipation from taking Welchol. In fact, constipation was one of the most common side effects that people taking Welchol reported in clinical trials.

Symptoms can include:

What you can do

If you experience constipation from taking Welchol, tell your doctor. They can recommend other medications that may help decrease this side effect. For example, your doctor may recommend taking MiraLAX (polyethylene glycol) or other drugs to decrease your constipation.

Muscle pain

Some people may experience muscle pain from taking Welchol. This was not a common side effect in clinical trials of the drug.

It’s also possible for other medications that you take along with Welchol to cause muscle pain. This may include statin drugs, such as Lipitor (atorvastatin).

What you can do

If you notice muscle pain during your treatment with Welchol, tell your doctor. They can determine what may be causing your muscle pain. And they’ll recommend the best ways to treat it. In some cases, they may recommend taking over-the-counter pain relievers, such as Tylenol (acetaminophen) or Advil (ibuprofen).

Nausea

Nausea may occur during Welchol treatment. It was one of the most common side effects that people taking Welchol reported in clinical trials.

What you can do

If you’re feeling nauseous from taking Welchol, tell your doctor. They may recommend ways to decrease this side effect. In some cases, your doctor may recommend other drugs to help decrease your nausea.

Allergic reaction

As with most drugs, Welchol can cause an allergic reaction in some people. However, it’s not clear whether this side effect occurred in clinical trials.

Symptoms can be mild or serious and can include:

  • skin rash
  • itching
  • flushing
  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep taking Welchol. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Be sure to talk with your doctor about your health history before you take Welchol. This drug may not be the right treatment for you if you have certain medical conditions or other factors that affect your health. These are considered drug-condition or drug-factor interactions. The conditions and factors to consider include:

High triglycerides. Tell your doctor before starting Welchol if you have high triglyceride levels.* You may have an increased risk of developing pancreatitis if you have high triglycerides and take Welchol.

If your triglyceride levels are greater than 500 milligrams per deciliter (mg/dL), your doctor will recommend a different treatment option for you. This is because Welchol is contraindicated† in people with triglyceride levels above 500 mg/dL. If you have high triglyceride levels that are less than 500 mg/dL, your doctor will likely recommend treating this before taking Welchol.

Pancreatitis related to high triglyceride levels. If you’ve ever had pancreatitis due to high triglyceride levels, tell your doctor before you start taking Welchol. Your doctor will likely recommend a different treatment option for you. This is because Welchol is contraindicated† in people who’ve had pancreatitis from high triglycerides. Be sure to discuss your medical history with your doctor before starting Welchol treatment.

Bowel obstruction or other digestive problems. If you’ve ever had a bowel obstruction,* also called an intestinal blockage, tell your doctor. Welchol may increase the risk of developing a bowel obstruction. And the drug is contraindicated† in people who ever had this condition. Also be sure to tell your doctor if you have any digestive problems, such as gastroparesis. This condition may further increase your risk of having a bowel obstruction. If you have digestive problems, your doctor may monitor you throughout your treatment for symptoms of bowel obstruction.

Phenylketonuria. Before starting treatment with Welchol, tell your doctor if you have phenylketonuria (PKU). The powder form of Welchol for oral suspension contains phenylalanine. This may be harmful to people with PKU. Talk with your doctor to see if you can use the powder form of Welchol or if the tablet is a better option for you.

Allergic reaction. If you’ve had an allergic reaction‡ to Welchol or any of its ingredients, your doctor will likely not prescribe Welchol. Ask your doctor what other medications may be better options for you.

Malabsorption syndromes. It’s possible for Welchol to cause vitamin deficiencies as a side effect.‡ If you have any malabsorption syndromes (conditions that decrease your absorption of nutrients), you may have an increased risk of developing a vitamin deficiency. If your doctor recommends you take vitamin supplements, be sure to take them 4 hours before your Welchol dose.

* For more information about this side effect, see the “Serious side effects of Welchol” section above.
† A contraindication is a factor or condition that could prevent your doctor from prescribing a drug due to risk of harm.
‡ To learn more about this side effect, see the “Side effect specifics” section above.

Alcohol with Welchol

Welchol is not known to interact with alcohol. However, it’s possible for alcohol to increase the risk and severity of certain side effects that you may have from Welchol. For example, Welchol causes nausea as a side effect. So, if you drink alcohol while taking Welchol, this may worsen nausea further.

Also, drinking alcohol heavily can also increase your risk of pancreatitis (swelling of your pancreas). Since Welchol may also cause pancreatitis as a side effect, drinking alcohol may further increase this risk.

In addition, alcohol may cause changes to your blood sugar levels, which can affect your diabetes treatment.

Alcohol may also have an effect on other drugs that you take along with Welchol. For example, alcohol may interact with statin drugs, such as Lipitor (atorvastatin).

Talk with your doctor to see if it’s safe for you to drink alcohol during your treatment with Welchol. If it’s safe for you to drink alcohol, your doctor can advise how much is safe.

Pregnancy and breastfeeding while taking Welchol

Currently, it isn’t known if it’s safe to take Welchol during pregnancy. However, it’s likely safe to take the drug while breastfeeding.

There haven’t been any studies done in pregnant people to determine if Welchol is safe. Welchol is not absorbed well into the body. So, it isn’t expected that developing fetuses will be exposed to the drug.

In animal studies, there wasn’t an increased risk of congenital anomalies (also known as birth defects) when the drug was given during pregnancy. However, it’s important to note that animal studies don’t always indicate what may happen in humans.

In addition, Welchol is unlikely to pass into breast milk. This is because Welchol is not absorbed well into the body. So, a breastfed child will likely not be exposed to the drug. For this reason, it’s likely safe to breastfeed while you’re taking Welchol.

If you’re pregnant, planning to become pregnant, or breastfeeding, talk with your doctor before starting Welchol treatment. They can help determine if the drug may be safe for you.

You may experience side effects from your treatment with Welchol. However, most side effects are mild. If you’d like to learn more about Welchol, talk with your doctor or pharmacist. They can help answer any questions you have about side effects from taking the drug.

Besides talking with your doctor, you can do some research on your own. These articles might help:

  • More information about Welchol. For details about other aspects of Welchol, refer to this article.
  • Dosage details. To learn about dosage information for Welchol, see this article.
  • A look at your condition. For more information about cholesterol, see our cholesterol hub and these related articles. And for details about type 2 diabetes, see our diabetes hub and this list of articles.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.