Drug & supplement interaction

Chitosan + Esomeprazole

Esomeprazole brand name: Nexium.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Chitosan and Esomeprazole 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 Esomeprazole 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 Esomeprazole

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 Esomeprazole 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 Esomeprazole and Chitosan? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Esomeprazole

Interactions in our licensed database are recorded against drug classes, not just single drug names. Esomeprazole is filed under 6 classifications — including proton pump inhibitors (ppis), cytochrome p450 2c19 (cyp2c19) inhibitors, cytochrome p450 1a2 (cyp1a2) inducers. Chitosan has documented interactions with 2 drug classes — the most serious being acyclovir (zovirax) (moderate) and warfarin (coumadin) (moderate) — and none of Esomeprazole’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 — Esomeprazole 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. Esomeprazole)
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 Esomeprazole 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. One of them is worth acting on rather than waiting out — marked below.

  • Kidney problems Worth acting on reported in 30.8% of FDA reports for Esomeprazole Additional detail

    Chitosan

    “In one clinical trial, a subject with kidney failure reported itching during 12 weeks of oral chitosan treatment. It is not clear if this was related to the underlying renal failure or the use of oral chitosan.”

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

    1 source 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

    Esomeprazole

    Listed in the ADVERSE REACTIONS section of the FDA label for Esomeprazole, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

  • Bloating or gas / Stomach upset / Constipation / Diarrhea / Nausea reported in 5.8% of FDA reports for Esomeprazole 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

    Esomeprazole

    Listed in the ADVERSE REACTIONS section of the FDA label for Esomeprazole, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

  • Itching Additional detail

    Chitosan

    “Topically, an eye drop containing chitosan-N-acetylcysteine has been reported to cause itching and irritation of the eyes.”

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

    1 source cited
    1. 97710. 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.

    Esomeprazole

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

Effects for Esomeprazole come from the ADVERSE REACTIONS section of its FDA label; effects for Chitosan come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 235,235 voluntary FDA FAERS reports for Esomeprazole that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. 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 Esomeprazole Products Have a Food Rule — Chitosan Should Not Break It

At least one FDA label for a product containing Esomeprazole 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 Esomeprazole 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 Esomeprazole 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.

Table 2: Recommended Dosage of Esomeprazole Magnesium Delayed-Release Capsules in Pediatric Patients by Indication Indication Patient Age Recommended Dosage Duration Healing of EE 12 years to 17 years Esomeprazole magnesium delayed-release capsules: 20 mg or 40 mg once daily 4 to 8 Weeks Treatment of Symptomatic GERD 12 years to 17 years Esomeprazole magnesium delayed-release capsules: 20 mg once

From the Dosage and Administration section of the FDA label we read for Esomeprazole — 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.

From our Q&A

Questions About Chitosan or Esomeprazole

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 Esomeprazole, 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 Esomeprazole

This page covers Chitosan only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Esomeprazole page lists 154 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 102 moderate · 49 minor.

From our pharmacist’s overview on the Esomeprazole page

“St. John's wort can lower the amount of esomeprazole (Nexium) in your blood by speeding up how the liver clears it, which can leave heartburn or ulcer treatment falling short.”

Reviewed by 2 · Jul 18, 2026

Open the Esomeprazole 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 Esomeprazole, 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 Esomeprazole 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
Steady interest

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

29 days ago today
Medication Esomeprazole
Steady interest

#1,509 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 13, 2026. The Chitosan and Esomeprazole 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 Esomeprazole

What Is Esomeprazole Used For?

Brand name: Nexium

Esomeprazole treats problems caused by excess stomach acid. It's used to heal erosive esophagitis (damage to the esophagus from acid), control GERD (gastroesophageal reflux disease) symptoms like heartburn, and protect the stomach lining in people at risk for ulcers caused by NSAIDs (anti-inflammatory pain relievers like ibuprofen).

It's also used as part of a three-drug combination to wipe out H. pylori — a stomach bacteria linked to ulcers — and for people with rare conditions that cause the stomach to overproduce acid, such as Zollinger-Ellison syndrome.

Most-Reported Side Effects for Esomeprazole

From FAERS, the FDA’s public side-effect reporting system (235,235 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Chronic kidney disease 35,589 reports
Acute kidney injury 20,510 reports
Renal failure 16,295 reports
Nausea 13,667 reports
Gastrooesophageal reflux disease 12,006 reports
See full Esomeprazole 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 Esomeprazole, 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 Esomeprazole Together: Common Questions

Is it safe to take Chitosan with Esomeprazole?
We do not list a known interaction between Chitosan and Esomeprazole. 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 Esomeprazole have any of the same side effects?
Yes — our sources link each of them separately to 7 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 Esomeprazole at the same time of day?
At least one FDA label for a product containing Esomeprazole 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 Esomeprazole 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.
How was the Chitosan and Esomeprazole combination checked?
Interactions in our licensed database are recorded against drug classes. Esomeprazole is filed under 6 classifications, and Chitosan has documented interactions with 2 drug classes — none of Esomeprazole'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 — Esomeprazole 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 Esomeprazole interact with any supplements?
Yes. Esomeprazole has documented interactions with 154 supplements in our database — Chitosan is not one of them. The Esomeprazole 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 Esomeprazole drug information The full plain-English guide to this medication Esomeprazole supplement interactions Every supplement checked against Esomeprazole, 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 Esomeprazole 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.