Drug & supplement interaction

Beta-glucans + Hydrochlorothiazide

Hydrochlorothiazide brand names: Esidrix, Hydro, Microzide, HydroDiuril, Hydro-D, and others.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Beta-glucans has a moderate interaction with Hydrochlorothiazide. Theoretically, taking beta-glucans with antihypertensive drugs might increase the risk of hypotension.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Beta-glucans and Hydrochlorothiazide

Here is the interaction we found between these two, with the evidence behind it.

Moderate

ANTIHYPERTENSIVE DRUGS

Why this applies to Hydrochlorothiazide

Hydrochlorothiazide falls under ANTIHYPERTENSIVE DRUGS — the group Beta-glucans interacts with.

Theoretically, taking beta-glucans with antihypertensive drugs might increase the risk of hypotension.
Clinical research shows that taking beta-glucans may reduce systolic and diastolic blood pressure in some hypertensive individuals.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the simple version: hydrochlorothiazide (Microzide) is a water pill that lowers your blood pressure. Beta-glucans, the soluble fiber found in oats and barley, may nudge blood pressure down a little on their own. So when you put the two together, the worry is just that the effects could stack and lower your pressure a bit more than expected.

If that happened, you might feel dizzy, lightheaded, or woozy when standing up quickly. To be honest, this is mostly a theoretical concern based on weak, anecdotal evidence, and the blood-pressure effect of beta-glucans tends to be modest. Most people do fine. I wouldn't lose sleep over a bowl of oatmeal, but if you're taking concentrated fiber supplements, mention it to your pharmacist or doctor so they can keep an eye on your numbers.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Katz, D. L., Nawaz, H., Boukhalil, J., Giannamore, V., Chan, W., Ahmadi, R., and Sarrel, P. M. Acute effects of oats and vitamin E on endothelial responses to ingested fat. Am.J.Prev.Med. 2001;20(2):124-129. PubMed
  2. Keenan, J. M., Pins, J. J., Frazel, C., Moran, A., and Turnquist, L. Oat ingestion reduces systolic and diastolic blood pressure in patients with mild or borderline hypertension: a pilot trial. J.Fam.Pract. 2002;51(4):369.
  3. Maki, K. C., Galant, R., Samuel, P., Tesser, J., Witchger, M. S., Ribaya-Mercado, J. D., Blumberg, J. B., and Geohas, J. Effects of consuming foods containing oat beta-glucan on blood pressure, carbohydrate metabolism and biomarkers of oxidative stress i

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Beta-glucans Also Interacts With Other Medications

Beta-glucans has 292 moderate known drug interactions in our database — the Hydrochlorothiazide one above is one of them. If you take anything else, check it against the full list below.

Moderate 292 No known interaction 2,538 (incl. Hydrochlorothiazide)
Taking anything else?

Check Another of Your Medications Against Beta-glucans

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

From our Q&A

Questions About Beta-glucans or Hydrochlorothiazide

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Beta-glucans or Hydrochlorothiazide, 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 Hydrochlorothiazide

This page covers Beta-glucans only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hydrochlorothiazide page lists 230 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Asarabacca (major) and Dolomite (major).

By severity: 10 major · 195 moderate · 25 minor.

From our pharmacist’s overview on the Hydrochlorothiazide page

“Hydrochlorothiazide sits at the strong end of the caution scale for supplement interactions, and the small group of major-rated entries deserves a careful read before everything else on the page. Most of what appears here either adds to the pill's blood-pressure-lowering effect or piles onto its diuretic action, pushing fluid and potas…”

Reviewed by 2 · Jul 18, 2026

Open the Hydrochlorothiazide interaction page

One more smart check

Taking Beta-glucans as Part of a Dietary Supplement Product? Check It for Interactions

We hold 809 real supplement products containing Beta-glucans, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Beta-glucans. Your product may carry other ingredients that interact with Hydrochlorothiazide too, on top of Beta-glucans — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Beta-glucans and Hydrochlorothiazide 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 Beta-glucans
Top 25%

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

29 days ago today
Medication Hydrochlorothiazide
Top 5%

#137 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.

Supplement

About Beta-glucans

What is Beta-glucans?

  • High cholesterol
  • Heart health
  • Immune support
  • Blood sugar control
  • Wound care (topical)

Beta-glucans are natural fibers found in oats, barley, mushrooms, and yeast. The strongest evidence supports the oat and barley types for modestly lowering cholesterol and blood sugar, while immune-related claims from yeast and mushroom sources are far less proven. They are generally well tolerated, but check with your pharmacist before starting any supplement.

Read the full Beta-glucans monograph & all interactions
Medication

About Hydrochlorothiazide

What Is Hydrochlorothiazide Used For?

Brand names: Esidrix, Hydro, Microzide, HydroDiuril, Hydro-D, Oretic, Aquazide H, Aquazide, HCTZ

Hydrochlorothiazide treats high blood pressure (hypertension) in adults and children, either alone or combined with other blood pressure medicines. Lowering blood pressure reduces the risk of strokes and heart attacks.

It also treats edema (fluid buildup) linked to congestive heart failure, hepatic cirrhosis (liver scarring), and kidney conditions including nephrotic syndrome. Hydrochlorothiazide tablets are additionally indicated for edema caused by corticosteroid or estrogen therapy, and edema from acute glomerulonephritis or chronic renal failure. Inzirqo (the oral suspension) is specifically approved for both hypertension and edema in adult and pediatric patients.

See full Hydrochlorothiazide drug information
Keep checking

Other Drugs & Beta-glucans

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

0Major
292Moderate
0Minor
2,537No known interaction
292 Moderate 2,537 No interaction
Moderate

292 interactions

Showing 60 of 292 moderate interactions — see all 292 on the Beta-glucans page.

No interaction 2,537 drugs checked — show the list

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

Showing the 60 most looked-up of 2,537 medications checked with no known interaction — see the full Beta-glucans list.

See the full Beta-glucans interactions page
See every supplement checked against Hydrochlorothiazide, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Beta-glucans monograph › Uses, safety, and every drug interaction in one place Hydrochlorothiazide supplement interactions › Every supplement checked against Hydrochlorothiazide, ranked by severity Hydrochlorothiazide drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Beta-glucans and Hydrochlorothiazide Together: Common Questions

Can you take Beta-glucans with Hydrochlorothiazide?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Beta-glucans and Hydrochlorothiazide interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Hydrochlorothiazide and Beta-glucans?

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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.