How Does Welchol Lower Cholesterol?

Welchol (Colesevelam) works differently than most other cholesterol medications. Instead of entering your bloodstream and affecting your liver directly (like statins do), Welchol works entirely inside your digestive system. Let's break down how this medication does its job in plain English.

The Basics: What Are Bile Acids?

To understand how Welchol works, you first need to know about bile acids. Bile acids are substances your liver makes from cholesterol. They get released into your intestines every time you eat, and their job is to help you digest fats from food.

Normally, after bile acids do their job in your intestines, most of them get reabsorbed back into your bloodstream and recycled by your liver. This is called the enterohepatic circulation — basically a recycling loop for bile acids.

How Welchol Breaks the Cycle

Welchol is a bile acid sequestrant — which is a fancy way of saying it "grabs" bile acids in your intestines and holds on to them. Here's the step-by-step process:

1. You take Welchol with a meal. The medication travels to your intestines along with your food.
2. Welchol binds to bile acids. The medication is a polymer (a large molecule with a special structure) that attracts and traps bile acids like a sponge.
3. Bile acids leave your body. Instead of being recycled, the bile acids bound to Welchol are eliminated in your stool.
4. Your liver makes more bile acids. Since the bile acid pool is now depleted, your liver needs to make new bile acids. To do this, it pulls cholesterol out of your blood.
5. Your LDL cholesterol drops. Your liver also increases the number of LDL receptors on its surface to capture more LDL cholesterol from the blood. The result? Lower LDL ("bad") cholesterol levels.

Think of it this way: Welchol forces your liver to use up cholesterol to replace the bile acids it lost, which lowers the amount of cholesterol circulating in your blood.

Why Welchol Stays in Your Gut

One important thing about Welchol: it is not absorbed into your bloodstream. The medication stays entirely in your digestive tract from start to finish. This is different from statins, which enter your blood and work directly on your liver cells.

Because Welchol doesn't enter your bloodstream, it tends to have fewer systemic side effects than some other medications. The trade-off is that most of its side effects are related to your digestive system — things like constipation and gas. For more on this, see: Welchol Side Effects: What to Expect.

How Does Welchol Help with Type 2 Diabetes?

Welchol is also FDA-approved to help control blood sugar in adults with type 2 diabetes. This might seem surprising for a cholesterol medication, but researchers have found that bile acids play a role in blood sugar regulation.

The exact mechanism for Welchol's blood sugar-lowering effect isn't completely understood, but scientists believe it involves:

• Changes in bile acid signaling. Bile acids activate certain receptors (like FXR and TGR5) that influence how your body handles glucose. By changing the mix of bile acids in your gut, Welchol may affect these signaling pathways.
• Effects on gut hormones. Welchol may increase the release of GLP-1, a hormone that helps your body produce insulin and manage blood sugar levels after meals.

While the diabetes benefit is a bonus for patients who also have high cholesterol, Welchol is not a substitute for primary diabetes medications like Metformin or insulin. It's used as an add-on therapy.

Welchol vs. Statins: What's the Difference?

People often wonder how Welchol compares to statins. Here are the key differences:

• Where they work: Statins work inside liver cells by blocking an enzyme called HMG-CoA reductase. Welchol works in your intestines by binding bile acids.
• Absorption: Statins are absorbed into your bloodstream. Welchol is not.
• LDL reduction: Statins typically lower LDL cholesterol by 30-50%. Welchol typically lowers LDL by 15-18% when used alone.
• Combination use: Welchol can be used together with statins for additional LDL lowering.
• Side effects: Statins can cause muscle pain and liver enzyme changes. Welchol mainly causes GI side effects like constipation and gas.

For patients who can't tolerate statins, Welchol is one of several alternatives. Learn about other options in our guide: Alternatives to Welchol.

Welchol vs. Other Bile Acid Sequestrants

Welchol isn't the only bile acid sequestrant available. Older medications in this class include:

• Cholestyramine (Questran): The oldest bile acid sequestrant. Comes as a powder that must be mixed with liquid. Known for a gritty texture and more GI side effects than Welchol.
• Colestipol (Colestid): Available as tablets and granules. Similar effectiveness to Welchol but may cause more GI symptoms.

Welchol was designed to be better tolerated than these older options, and it comes in more convenient forms (tablets, suspension, and chewable bars).

Why Take Welchol with Meals?

Welchol needs to be in your intestines when bile acids are released. Bile acids are released in response to eating, especially fatty foods. Taking Welchol with a meal ensures it's in the right place at the right time to bind those bile acids.

If you take Welchol on an empty stomach, it won't work as well because there won't be as many bile acids for it to bind.

Does Welchol Affect Other Medications?

Yes. Because Welchol binds substances in your intestines, it can also bind to other medications and reduce their absorption. This is why you need to take certain medications at least 4 hours before Welchol. For a complete list, see: Welchol Drug Interactions: What to Avoid.

Key Takeaways

• Welchol binds bile acids in your gut, forcing your liver to use cholesterol to make more — which lowers your LDL
• It is not absorbed into your bloodstream, so it has fewer systemic side effects
• It also helps lower blood sugar in type 2 diabetes, possibly through effects on gut hormones
• Always take Welchol with a meal so it can work properly
• Space other medications at least 4 hours before Welchol

For complete information about Welchol dosage and how to take it, read: What Is Welchol? Uses, Dosage, and What You Need to Know. If you need help finding Welchol at a pharmacy, visit MedFinder or read: How to Find Welchol in Stock Near You.