Over-the-counter medication · Bulk-Forming Laxative
psyllium
Also sold as Metamucil. Metamucil is used to relieve constipation that happens from time to time.
Data updated 2026-05-15
- OTC
- Availability
psyllium (Metamucil) is an over-the-counter Bulk-Forming Laxative. Metamucil is used to relieve constipation that happens from time to time.
Metamucil is a fiber supplement that helps you have regular bowel movements. It is a bulk-forming laxative.
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What it does
Metamucil is used to relieve constipation that happens from time to time.
Common side effects
Changes in bowel habits, Minor bloating
Key warnings
Taking this product without enough liquid may cause choking.
The sections below are summarized in plain English from psyllium's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Metamucil contains psyllium, a type of fiber. This fiber absorbs water in your intestines. This makes your stool softer and easier to pass.
Serious Warnings
Taking this product without enough liquid may cause choking. Be sure to mix with at least 8 ounces of water or other fluid and drink promptly.
Common Questions
How quickly will Metamucil work?
Can children under 12 take Metamucil?
What happens if the mixture gets too thick?
Can I take Metamucil with other medications?
How much liquid should I use?
What should I do if I experience bloating?
Can I take Metamucil every day?
What is the active ingredient in Metamucil?
Does Metamucil have a taste?
What should I do if Metamucil doesn't work?
What are the common side effects of psyllium?
What drug class is psyllium?
What pregnancy or breastfeeding source fields are listed for psyllium?
Related Medications in Bulk-Forming Laxative
Other drugs grouped near psyllium - same-class peers and common alternatives.
alosetron
Lotronex
Alosetron (Lotronex) is a medicine for women with severe diarrhea-predominant irritable bowel syndrome (IBS).
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aprepitant
Emend
Aprepitant (Emend) is a medicine that helps prevent nausea and vomiting.
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bisacodyl
Dulcolax
Bisacodyl is a medicine that helps you have a bowel movement.
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bismuth subsalicylate
Pepto-Bismol
Bismuth subsalicylate (Pepto-Bismol) is a medicine that can treat diarrhea and upset stomach.
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cimetidine
Tagamet
Cimetidine (Tagamet) reduces stomach acid.
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What the FDA Data Shows for psyllium
The FDA label for psyllium (sold under brand names such as Metamucil) classifies it as an over-the-counter product in the Bulk-Forming Laxative class. Metamucil is used to relieve constipation that happens from time to time. Official labeling lists 2 commonly reported side effects, including Changes in bowel habits, Minor bloating.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. Voluntary reports accumulate over the lifetime of a drug and reflect wide-ranging clinical use. Interaction data is drawn directly from FDA-approved prescribing information. Acquisition-cost data is surveyed weekly by CMS and updated as manufacturers report changes.
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 are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.
Last updated: January 30, 2025
PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.
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 from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.
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