Drug & supplement interaction

Equol + Methazolamide

Methazolamide brand name: Neptazane.

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

Equol has a minor interaction with Methazolamide. Theoretically, equol might cause additive diuretic effects when used with diuretic drugs.

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

Equol and Methazolamide

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

Minor

DIURETIC DRUGS

Why this applies to Methazolamide

Methazolamide falls under DIURETIC DRUGS — the group Equol interacts with.

Theoretically, equol might cause additive diuretic effects when used with diuretic drugs.
In vitro and animal studies suggest that equol has diuretic effects, likely via inhibition of the Na-K-Cl cotransporter.
Severity Minor Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

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

Here's the gist: methazolamide is a carbonic anhydrase inhibitor used for glaucoma, but it also has a mild diuretic (water-pill) effect. Lab and animal studies hint that equol may have its own gentle diuretic action by blocking a salt transporter in the kidney. So in theory, pairing the two could add up to a bit more fluid and salt loss.

I want to be honest about how soft this evidence is. It comes only from test-tube and animal research, the interaction is rated minor and unlikely, and we have no real human reports here. If you do use both, just keep an eye out for things like extra urination, lightheadedness, dry mouth, or tingling in the hands and feet, which methazolamide can cause on its own. Run it by your pharmacist or doctor first, especially if you take other blood pressure or fluid medicines.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Gimenez I, Lou M, Vargas F, et al. Renal and vascular actions of equol in the rat. J Hypertens 1997;15:1303-8. PubMed
  2. Martinez RM, Gimenez I, Lou JM, et al. Soy isoflavonoids exhibit in vitro biological activities of loop diuretics. Am J Clin Nutr 1998;68:1354S-57S. PubMed
  3. Alda JO, Mayoral JA, Lou M, et al. Purification and chemical characterization of a potent inhibitor of the Na-K-Cl cotransport system in rat urine. Biochem Biophys Res Commun 1996;221:279-85. PubMed

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

Equol Also Interacts With Other Medications

Equol has 58 moderate, 74 minor known drug interactions in our database — the Methazolamide one above is one of them. If you take anything else, check it against the full list below.

Moderate 58 Minor 74 No known interaction 2,698 (incl. Methazolamide)
Taking anything else?

Check Another of Your Medications Against Equol

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

Everything else you take

See Every Supplement That Interacts With Methazolamide

This page covers Equol only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methazolamide page lists 218 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), Lithium (major) and Oleander (major).

By severity: 7 major · 187 moderate · 24 minor.

From our pharmacist’s overview on the Methazolamide page

“Methazolamide (Neptazane) treats glaucoma by lowering pressure inside the eye, and because it also has mild water-pill effects it can nudge blood pressure and potassium on its own. That is exactly where most of the 218 supplements on this page press, and the list earns real caution.”

Reviewed by 2 · Jul 18, 2026

Open the Methazolamide interaction page

How much people look this up

Where Equol and Methazolamide 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 Equol
Steady interest

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

29 days ago today
Medication Methazolamide
Top 25%

#636 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 Equol

What is Equol?

  • Menopause symptoms (hot flashes)
  • Bone health support
  • Skin aging
  • Prostate health
  • General hormone balance

Equol is a compound made in the gut when some people break down soy isoflavones, and it is also sold as a supplement. Early research links it to possible benefits for menopause symptoms and bone or skin health, but the evidence is still limited and far from proven. Talk with your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Read the full Equol monograph & all interactions
Medication

About Methazolamide

What Is Methazolamide Used For?

Brand name: Neptazane

Methazolamide tablets are used to treat eye conditions where lowering intraocular pressure (pressure inside the eye) is expected to help. These include chronic open-angle glaucoma and secondary glaucoma.

Methazolamide tablets are also used before surgery in acute angle-closure glaucoma, when reducing eye pressure ahead of the procedure is needed. Note that long-term use in angle-closure glaucoma is not appropriate.

See full Methazolamide drug information
Keep checking

Other Drugs & Equol

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

0Major
58Moderate
74Minor
2,697No known interaction
58 Moderate 74 Minor 2,697 No interaction
Moderate

58 interactions

Minor

74 interactions

Showing 60 of 74 minor interactions — see all 74 on the Equol page.

No interaction 2,697 drugs checked — show the list

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

Showing the 60 most looked-up of 2,697 medications checked with no known interaction — see the full Equol list.

See the full Equol interactions page
See every supplement checked against Methazolamide, 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
Equol monograph › Uses, safety, and every drug interaction in one place Methazolamide supplement interactions › Every supplement checked against Methazolamide, ranked by severity Methazolamide 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 Equol and Methazolamide Together: Common Questions

Can you take Equol with Methazolamide?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Equol and Methazolamide interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Methazolamide and Equol?

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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.