What the label lists and what reports show
Colesevelam side effects
Colesevelam's FDA label: “In clinical trials, the most common (incidence ≥2% and greater than placebo) adverse reactions with colesevelam hydrochloride included constipation, dyspepsia, and nausea ( 6.1 ).” FAERS holds 2,013 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is diarrhoea (241 reports).
- Generic listed
Check it at the source: the colesevelam FDA label on DailyMed (effective December 28, 2023, A-S Medication Solutions); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsIn clinical trials, the most common (incidence ≥2% and greater than placebo) adverse reactions with colesevelam hydrochloride included constipation, dyspepsia, and nausea ( 6.1 ).
Table 1 Clinical Studies of Colesevelam Hydrochloride for Primary Hyperlipidemia: Adverse Reactions Reported in ≥ 2% of Patients and More Commonly than in Placebo
| Reaction | Colesevelam Hydrochloride N=807 | Placebo N=258 |
|---|---|---|
| Constipation | 11.0% | 7.0% |
| Dyspepsia | 8.3% | 3.5% |
| Nausea | 4.2% | 3.9% |
| Accidental injury | 3.7% | 2.7% |
| Asthenia | 3.6% | 1.9% |
| Pharyngitis | 3.2% | 1.9% |
| Flu syndrome | 3.2% | 3.1% |
| Rhinitis | 3.2% | 3.1% |
| Myalgia | 2.1% | 0.4% |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following important adverse reactions are described below and elsewhere in the labeling: Hypertriglyceridemia and Pancreatitis [see Warnings and Precautions (5.1) ] Gastrointestinal Obstruction [see Warnings and Precautions (5.2) ] Vitamin K or Fat-Soluble Vitamin Deficiencies [see Warnings and Precautions (5.3) ] In clinical trials, the most common (incidence ≥2% and greater than placebo) adverse reactions with colesevelam hydrochloride included constipation, dyspepsia, and nausea ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Cosette Pharmaceuticals, Inc. at 1-800-922-1038 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Studies Experience Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in clinical studies of another drug and may not reflect the rates observed in practice. Primary Hyperlipidemia In 7 double-blind, placebo-controlled clinical trials, 807 patients with primary hyperlipidemia (age range 18-86 years, 50% women, 90% Caucasians, 7% Blacks, 2% Hispanics, 1% Asians) and elevated LDL-C were treated with colesevelam hydrochloride 1.5 g/day to 4.5 g/day from 4 to 24 weeks (total exposure 199 patient-years).
Source: FDA drug label, NDA021176 (Cosette), as published by A-S Medication Solutions, effective December 28, 2023 (SPL set 0127afae-8d8d-43f2-97f9-4f99f6947e81), via openFDA; the full label on DailyMed
What do FAERS reports show?
2,013 reports list colesevelam among the medicines taken, each a report of something that happened, not proof the medicine caused it; 48 are coded as a death and 513 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 23 reactions below, 3 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Colesevelam: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions