Prescription medication · Bile Acid Sequestrant (Diabetes)
colesevelam
Also sold as Welchol. This medicine can help lower high LDL cholesterol in adults and children (10-17 years old) who have primary hyperlipidemia or heterozygous familial hypercholesterolemia.
Data updated 2026-05-15
- 952
- FDA reportsRarely reported
- 15
- InteractionsSeveral interactions
- 95% less
- Generic vs brandHuge savings
- $4.72
- Brand price (NADAC)
What the data shows
colesevelam (Welchol) is a prescription Bile Acid Sequestrant (Diabetes), among the least-reported drugs the FDA tracks (952 FDA reports), whose generic costs a fraction of the brand (about 95% less).
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
colesevelam (Welchol) is a prescription Bile Acid Sequestrant (Diabetes). This medicine can help lower high LDL cholesterol in adults and children (10-17 years old) who have primary hyperlipidemia or heterozygous familial hypercholesterolemia.
Colesevelam is a medicine that helps lower bad cholesterol (LDL-C) and control blood sugar in adults. It can also lower LDL-C in children ages 10-17 with certain cholesterol problems.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Brand Price
$4.72/unit
Generic Price
$0.22/unit
Generic Savings
95%
Generic Available
Yes (11 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
This medicine can help lower high LDL cholesterol in adults and children (10-17 years old) who have primary hyperlipidemia or heterozygous familial hypercholesterolemia.
Common side effects
Constipation, Upset stomach, Nausea
Key warnings
Colesevelam can raise your triglyceride levels, which could cause pancreatitis.
The sections below are summarized in plain English from colesevelam's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Colesevelam is a bile acid sequestrant. It works by binding to bile acids in your gut. This helps your body get rid of cholesterol and can also lower blood sugar levels.
How to Take It
The usual dose is 3.75 grams per day. You can take six tablets once a day, or three tablets twice a day with a meal and liquid. If you take the oral suspension, mix one packet with 1 cup of water, juice, or diet soda and drink it with a meal.
This is a plain-language summary of colesevelam's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
Pregnancy & Breastfeeding
This medicine is not absorbed into your body, so it is not expected to harm your baby during pregnancy. Talk to your doctor if you are pregnant or plan to become pregnant. This medicine is also not expected to pass into breast milk.
This is a plain-language summary of colesevelam's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule.
This is a plain-language summary of colesevelam's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store this medicine at room temperature, away from moisture and heat.
Side Effects (from patient reports)
Based on 952 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for colesevelam, by number of reports
- Diarrhea
Diarrhea
121 reports
- Shortness of breath
Shortness of breath
72 reports
- Cough
Cough
64 reports
- Muscle cramps
Muscle cramps
61 reports
- Tiredness
Tiredness
59 reports
- Feeling sick to your stomach
Feeling sick to your stomach
59 reports
- Common cold
Common cold
56 reports
- Heart problem
Heart problem
49 reports
- Stomach pain 48
Stomach pain
48 reports
- Irregular heartbeat 48
Irregular heartbeat
48 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for colesevelam each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where colesevelam sits
colesevelam has more FDA adverse-event reports than 7% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is colesevelam; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 952 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2006–2025.
Total Reports
952
Reports Mentioning Death
32
3.4% of reports — not proof of cause
Hospitalization Reports
277
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | DIARRHOEA | 121 |
| 2 | DYSPNOEA | 72 |
| 4 | COUGH | 64 |
| 6 | MUSCLE SPASMS | 61 |
| 7 | FATIGUE | 59 |
| 8 | NAUSEA | 59 |
| 9 | NASOPHARYNGITIS | 56 |
| 10 | CARDIAC DISORDER | 49 |
| 11 | ABDOMINAL PAIN | 48 |
| 12 | ATRIAL FIBRILLATION | 48 |
| 13 | CHEST DISCOMFORT | 48 |
| 14 | DYSPNOEA EXERTIONAL | 46 |
| 15 | DYSPHONIA | 45 |
| 16 | CORONARY ARTERY DISEASE | 43 |
| 17 | EOSINOPHILIA | 43 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Colesevelam can raise your triglyceride levels, which could cause pancreatitis. Tell your doctor right away if you have severe stomach pain. This medicine may also cause bowel obstruction, especially if you have stomach problems or have had major surgery on your stomach or intestines. Colesevelam can also lower the amount of fat-soluble vitamins your body absorbs.
Known Drug Interactions
7 DRUG INTERACTIONS Lithium: Risk of lithium toxicity ( 7.2 ) Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): Reduced diuretic, natriuretic and antihypotensive effects; increased risk of renal toxicity ( 7.3 ) Dual inhibition of the renin-angiotensin system: Increased risk of renal impairment, hypotension, and hyperkalemia ( 7.4 ) Colesevelam hydrochloride: Consider administering olmesartan at least 4 hours before colesevelam hydrochloride dose ( 7.5 ) Antidiabetic drugs: Dosage adjustment may be required ( 7.6 ) Cholestyramine and colestipol: Reduced absorption of thiazides ( 7.6 ) 7.1...
Mechanism: Colesevelam can stick to olmesartan in your stomach, which prevents your body from absorbing the blood pressure medicine correctly.
What to do: You should take your olmesartan dose at least 4 hours before you take colesevelam.
Concomitant use with colesevelam hydrochloride may increase the exposure of the following drugs: Metformin extended release. 7.2 Colesevelam Hydrochloride Drug Interactions that Increase the Exposure of the Concomitant Medication Table 5 Colesevelam Hydrochloride Drug Interactions that Increase the Exposure of the Concomitant Medication Metformin Extended Release (ER) Clinical Impact: In vivo drug interactions studies showed an increase in metformin extended release (ER) when coadministered with colesevelam hydrochloride [see Clinical Pharmacology (12.3) ].
Mechanism: Colesevelam can raise the levels of metformin in your body by increasing how much of the drug you are exposed to.
What to do: Your doctor may need to monitor your blood sugar more often or adjust your metformin dosage.
7 DRUG INTERACTIONS Concomitant use with colesevelam hydrochloride may decrease the exposure of the following drugs: Drugs with a narrow therapeutic index (e.g., cyclosporine), phenytoin, thyroid hormone replacement therapy, warfarin, oral contraceptives containing ethinyl estradiol and norethindrone, olmesartan medoxomil, and sulfonylureas (glimepiride, glipizide, glyburide). For patients on warfarin, monitor International Normalized Ratio (INR) frequently during initiation then periodically ( 7.1 ). Warfarin Clinical Impact: There have been postmarketing reports of reduced INR in...
Mechanism: Colesevelam can lower the amount of warfarin that gets into your blood by binding to the medicine in your stomach. This prevents the warfarin from being absorbed properly into your system.
What to do: Your doctor should check your blood clotting levels (INR) frequently when you start or stop this medication. They may need to adjust your warfarin dose.
7 DRUG INTERACTIONS Concomitant use with colesevelam hydrochloride may decrease the exposure of the following drugs: Drugs with a narrow therapeutic index (e.g., cyclosporine), phenytoin, thyroid hormone replacement therapy, warfarin, oral contraceptives containing ethinyl estradiol and norethindrone, olmesartan medoxomil, and sulfonylureas (glimepiride, glipizide, glyburide). Oral Contraceptives Containing Ethinyl Estradiol and Norethindrone Clinical Impact: In vivo drug interactions studies showed a decrease in exposure of ethinyl estradiol and norethindrone when coadministered with...
Mechanism: Colesevelam can reduce the amount of birth control medicine that enters your body. This happens because the drug can trap the birth control in your digestive system before it can work.
What to do: Talk to your doctor about the best timing for taking these medications to ensure your birth control stays effective. You may need to take them several hours apart.
7 DRUG INTERACTIONS Concomitant use with colesevelam hydrochloride may decrease the exposure of the following drugs: Drugs with a narrow therapeutic index (e.g., cyclosporine), phenytoin, thyroid hormone replacement therapy, warfarin, oral contraceptives containing ethinyl estradiol and norethindrone, olmesartan medoxomil, and sulfonylureas (glimepiride, glipizide, glyburide). In vivo drug interactions studies showed a decrease in exposure of cyclosporine when coadministered with colesevelam hydrochloride [see Clinical Pharmacology (12.3) ]. Examples: Cyclosporine Phenytoin Clinical...
Mechanism: Colesevelam can lower the levels of cyclosporine in your body by blocking its absorption. This means there might not be enough medicine in your blood to work correctly.
What to do: Your doctor should monitor your blood levels of cyclosporine closely. They may need to adjust your dose or change when you take the medicine.
This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.
Common Questions
Can I take this with other medications?
What if I have trouble swallowing the tablets?
Can this medicine cause weight gain?
Will this medicine cure my diabetes or high cholesterol?
How long will it take to see results?
Are there any foods I should avoid while taking this medicine?
Can I drink alcohol while taking this medicine?
What should I do if I experience side effects?
Is there a generic version of this medicine?
Can children take this medicine?
What are the common side effects of colesevelam?
Does colesevelam interact with other medications?
What drug class is colesevelam?
Is there a generic version of colesevelam?
Is colesevelam safe during pregnancy?
Related Medications in Bile Acid Sequestrant (Diabetes)
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dapagliflozin
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Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
Why some drugs demand precise dosing and monitoring
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
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What the FDA Data Shows for colesevelam
The FDA label for colesevelam (sold under brand names such as Welchol) classifies it as a prescription-only medication in the Bile Acid Sequestrant (Diabetes) class. This medicine can help lower high LDL cholesterol in adults and children (10-17 years old) who have primary hyperlipidemia or heterozygous familial hypercholesterolemia. Official labeling lists 14 commonly reported side effects, including Constipation, Upset stomach, Nausea.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 952 voluntary reports. The database also lists 15 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated moderate severity. NADAC pricing from CMS shows a generic unit cost of $0.22 versus $4.72 for the brand - a 95% generic savings.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: December 28, 2023
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages