Drug & supplement interaction

Chitosan + Colestipol

Colestipol brand name: Colestid.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Chitosan and Colestipol in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Colestipol states a food rule worth keeping to, and the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Chitosan and Colestipol

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Colestipol and Chitosan in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Chitosan safety at a glance

Chitosan overall Use caution Generally well tolerated short-term, but quality evidence is limited and shellfish allergy is a concern.
Pregnancy Avoid Not enough safety data; avoid use during pregnancy.
Breastfeeding Avoid Not enough safety data; avoid use while breastfeeding.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Colestipol and Chitosan? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Colestipol

Interactions in our licensed database are recorded against drug classes, not just single drug names. Colestipol is filed under 2 classifications — bile acid sequestrants, oral drugs. Chitosan has documented interactions with 2 drug classes — the most serious being acyclovir (zovirax) (moderate) and warfarin (coumadin) (moderate) — and none of Colestipol’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Chitosan Does Interact With Other Medications

Chitosan has 3 moderate known drug interactions in our database — Colestipol isn’t one of them. If you take anything else, check it against the full list below.

Moderate 3 No known interaction 2,827 (incl. Colestipol)
Taking anything else?

Check Another of Your Medications Against Chitosan

Covers the 2,830 medications we’ve checked against Chitosan. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Chitosan and Colestipol May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Bloating or gas / Stomach upset / Constipation / Diarrhea / Nausea Additional detail

    Chitosan

    “Orally, chitosan has been reported to cause epigastric discomfort, constipation, flatulence, diarrhea, nausea, and dryness of the throat. Excessive discharge of fat in the feces, also known as steatorrhea, has been reported with chitosan therapy.”

    Chitosan · Natural Medicines adverse-effect record, reported in constipation.

    6 sources cited
    1. 1942. Jing SB, Li L, Ji D, et al. Effect of chitosan on renal function in patients with chronic renal failure. J Pharm Pharmacol 1997;49:721-3. PubMed
    2. 3243. Pittler MH, Abbot NC, Harkness EF, Ernst E. Randomized, double-blind trial of chitosan for body weight reduction. Eur J Clin Nutr 1999;53:379-81. PubMed
    3. 9986. Ho SC, Tai ES, Eng PH, et al. In the absence of dietary surveillance, chitosan does not reduce plasma lipids or obesity in hypercholesterolaemic obese Asian subjects. Singapore Med J 2001;42:6-10.
    4. 11307. Bokura H, Kobayashi S. Chitosan decreases total cholesterol in women: a randomized, double-blind, placebo-controlled trial. Eur J Clin Nutr 2003;57:721-5. PubMed
    5. 14314. Mhurchu CN, Poppitt SD, McGill AT, et al. The effect of the dietary supplement, Chitosan, on body weight: a randomised controlled trial in 250 overweight and obese adults. Int J Obes Relat Metab Disord 2004;28:1149-56. PubMed
    6. 41688. Wuolijoki, E., Hirvela, T., and Ylitalo, P. Decrease in serum LDL cholesterol with microcrystalline chitosan. Methods Find.Exp Clin Pharmacol. 1999;21(5):357-361. PubMed

    Colestipol

    Listed in the ADVERSE REACTIONS section of the FDA label for Colestipol. Read the label on DailyMed ›

Reported for Chitosan but not commonly for Colestipol: kidney problems and itching.

Effects for Colestipol come from the ADVERSE REACTIONS section of its FDA label; effects for Chitosan come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

How to take them

Some Colestipol Products Have a Food Rule — Chitosan Should Not Break It

At least one FDA label for a product containing Colestipol says to take it on an empty stomach. Most supplements — Chitosan included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Colestipol on its own and move Chitosan to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Colestipol products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

Patients should take other drugs at least one hour before or four hours after colestipol hydrochloride tablets to minimize possible interference with their absorption.

From the Dosage and Administration section of the FDA label we read for Colestipol — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Overlapping uses

What Colestipol Is Prescribed For, and What Chitosan Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Colestipol is a prescription medicine with approved uses on its FDA label. Chitosan is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Colestipol is prescribed for: Colestipol — available as oral suspension and tablets under brands including Colestid, Flavored Colestid, and Colestipol Hydrochloride — is used as part of a broader treatment plan (including diet) to lower elevated LDL cholesterol in adults with primary hypercholesterolemia (a condition where LDL cholesterol stays high despite dietary changes). It is not a standalone fix. Diet, weight management, and other lifestyle changes come first, and colestipol is added when those steps alone aren't enough to reach target LDL levels.

Chitosan has been studied for:

  • Hypercholesterolemia studied, not established Chitosan has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Chitosan for hypercholesterolemia

    Despite conflicting study results in patients with hypercholesterolemia, a meta-analysis of small clinical studies suggests that oral chitosan may slightly improve lipid levels when taken for at least 4 weeks in overweight or obese patients with or without hypercholesterolemia.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Colestipol on your own; if you are taking Chitosan for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Chitosan or Colestipol

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Chitosan or Colestipol, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Colestipol

This page covers Chitosan only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Colestipol page lists 18 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 8 moderate · 9 minor.

From our pharmacist’s overview on the Colestipol page

“Take colestipol (Colestid), a cholesterol drug that works by trapping bile acids in your gut, and nearly every one of the 18 supplement interactions on file comes down to absorption. Only one rates major, activated charcoal, and it belongs at the top of your reading.”

Reviewed by 2 · Jul 18, 2026

Open the Colestipol interaction page

One more smart check

Taking Chitosan as Part of a Dietary Supplement Product? Check It for Interactions

We hold 167 real supplement products containing Chitosan, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Chitosan. Even though Chitosan itself has no known interaction with Colestipol, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Chitosan and Colestipol Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Chitosan
Top half

#467 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Colestipol
Top half

#718 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Chitosan reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Chitosan and Colestipol records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Chitosan

What is Chitosan?

Chitosan
  • Weight management
  • Lowering cholesterol
  • Wound care
  • General digestive supplement

Chitosan is a fiber-like substance made from the shells of shrimp, crabs, and other shellfish, often marketed for weight loss and cholesterol. The evidence for these benefits is weak, and any effects appear small at best. It is generally well tolerated for short-term use, but people with shellfish allergies and those who are pregnant or breastfeeding should be cautious.

Shells of crustaceans (the source of chitin, which is processed into chitosan) · Capsules, tablets, powder

An interaction check asks whether these two react with each other — it does not ask whether Chitosan is a good idea for someone in your situation. Here is what our Chitosan record says about it on its own.

Chitosan: dosing

There is no official standardized dose for chitosan, and amounts used in studies have varied widely. Because of this, it is best to follow the directions on the product label and not exceed them.Chitosan is often taken with meals and a full glass of water.

From our Chitosan monograph — the full record covers uses, side effects and every documented interaction.

Read the full Chitosan monograph & all interactions
Medication

About Colestipol

What Is Colestipol Used For?

Brand name: Colestid

Colestipol — available as oral suspension and tablets under brands including Colestid, Flavored Colestid, and Colestipol Hydrochloride — is used as part of a broader treatment plan (including diet) to lower elevated LDL cholesterol in adults with primary hypercholesterolemia (a condition where LDL cholesterol stays high despite dietary changes).

It is not a standalone fix. Diet, weight management, and other lifestyle changes come first, and colestipol is added when those steps alone aren't enough to reach target LDL levels.

See full Colestipol drug information
Keep checking

Other Drugs & Chitosan

Browse every other medication we’ve checked against Chitosan — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
3Moderate
0Minor
2,826No known interaction
3 Moderate 2,826 No interaction
Moderate

3 interactions

No interaction 2,826 drugs checked — show the list

We also checked Chitosan against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,826 medications checked with no known interaction — see the full Chitosan list.

See the full Chitosan interactions page
See every supplement checked against Colestipol, ranked by severity
Evidence & sources

Chitosan References

The 17 references that drive our Chitosan monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Jing SB, Li L, Ji D, et al. Effect of chitosan on renal function in patients with chronic renal failure. J Pharm Pharmacol 1997;49:721-3. PubMed
  2. Pittler MH, Abbot NC, Harkness EF, Ernst E. Randomized, double-blind trial of chitosan for body weight reduction. Eur J Clin Nutr 1999;53:379-81. PubMed
  3. Ho SC, Tai ES, Eng PH, et al. In the absence of dietary surveillance, chitosan does not reduce plasma lipids or obesity in hypercholesterolaemic obese Asian subjects. Singapore Med J 2001;42:6-10.
  4. Bokura H, Kobayashi S. Chitosan decreases total cholesterol in women: a randomized, double-blind, placebo-controlled trial. Eur J Clin Nutr 2003;57:721-5. PubMed
  5. Mhurchu CN, Poppitt SD, McGill AT, et al. The effect of the dietary supplement, Chitosan, on body weight: a randomised controlled trial in 250 overweight and obese adults. Int J Obes Relat Metab Disord 2004;28:1149-56. PubMed
  6. Huang SS, Sung SH, Chiang CE. Chitosan potentiation of warfarin effect. Ann Pharmacother 2007;41:1912-4. PubMed
  7. Tsai, G. J. and Su, W. H. Antibacterial activity of shrimp chitosan against Escherichia coli. J Food Prot. 1999;62(3):239-243. PubMed
  8. Wuolijoki, E., Hirvela, T., and Ylitalo, P. Decrease in serum LDL cholesterol with microcrystalline chitosan. Methods Find.Exp Clin Pharmacol. 1999;21(5):357-361. PubMed
  9. Nelson, J. L., Alexander, J. W., Gianotti, L., Chalk, C. L., and Pyles, T. Influence of dietary fiber on microbial growth in vitro and bacterial translocation after burn injury in mice. Nutrition 1994;10(1):32-36.
  10. Schiller RN, Barrager E, Schauss EA, and et al. A randomized, double-blind, placebo-controlled study examining the effects of a rapidly soluble chitosan dietary supplement on weight loss and body composition in overweight and mildly obese individuals. J
  11. Koide, S. S. Chitin-chitosan: properties, benefits and risks. Nutrition Research 1998;8(6):1091-1101. DOI
  12. Maezaki Y, Tsuji K, Nakawa, and et al. Hypocholesterolaemic effect of chitosan in adult males. Biosc Biochem Biotech 1993;57:1439-1444.
  13. Kubbinga M, Nguyen MA, Staubach P, et al. The influence of chitosan on the oral bioavailability of acyclovir-a comparative bioavailability study in humans. Pharm Res 2015;32(7):2241-9. PubMed
  14. Jull AB, Ni Mhurchu C, Bennett DA, et al. Chitosan for overweight or obesity. Cochrane Database Syst Rev 2008;(3):CD003892. PubMed
  15. Schmidl D, Werkmeister R, Kaya S, et al. A Controlled, Randomized Double-Blind Study to Evaluate the Safety and Efficacy of Chitosan-N-Acetylcysteine for the Treatment of Dry Eye Syndrome. J Ocul Pharmacol Ther. 2017;33(5):375-382.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Chitosan and Colestipol Together: Common Questions

Is it safe to take Chitosan with Colestipol?
We do not list a known interaction between Chitosan and Colestipol. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Chitosan and Colestipol have any of the same side effects?
Yes — our sources link each of them separately to 5 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Should I take Chitosan and Colestipol at the same time of day?
At least one FDA label for a product containing Colestipol says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Colestipol on its own and move Chitosan to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.
Are Chitosan and Colestipol used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Chitosan in each. That is a conversation for your prescriber, especially if Colestipol is being adjusted to a target.
How was the Chitosan and Colestipol combination checked?
Interactions in our licensed database are recorded against drug classes. Colestipol is filed under 2 classifications, and Chitosan has documented interactions with 2 drug classes — none of Colestipol's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Chitosan interact with any other medications?
Yes. Chitosan has 3 documented drug interactions in our database — Colestipol is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Colestipol interact with any supplements?
Yes. Colestipol has documented interactions with 18 supplements in our database — Chitosan is not one of them. The Colestipol interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Chitosan monograph Uses, safety profile, and every drug interaction in one place Colestipol drug information The full plain-English guide to this medication Colestipol supplement interactions Every supplement checked against Colestipol, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 17 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Colestipol and Chitosan?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.