Drug & supplement interaction

Potassium + Captopril

Captopril brand names: Capoten, Acepril.

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

Potassium has a moderate interaction with Captopril. Using ACEIs with high doses of potassium increases the risk of hyperkalemia.

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

Potassium and Captopril

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

Moderate

ACE INHIBITORS (ACEIs)

Why this applies to Captopril

Captopril falls under ACE INHIBITORS (ACEIs) — the group Potassium interacts with.

Using ACEIs with high doses of potassium increases the risk of hyperkalemia.
ACEIs block the actions of the renin-angiotensin-aldosterone system and reduce potassium excretion. Concomitant use of these drugs with potassium supplements increases the risk of hyperkalemia. However, concomitant use of these drugs with moderate dietary potassium intake (about 3775-5200 mg daily) does not increase serum potassium levels.
Severity Moderate Likelihood Likely Evidence C

Well-controlled human studies have demonstrated the likely existence of this interaction.

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

Here's the thing to know about pairing Captopril with a potassium supplement. Captopril works by quieting a hormone system that normally helps your kidneys flush out extra potassium. So while it's lowering your blood pressure, it's also nudging your potassium levels upward on its own. Add a concentrated potassium supplement on top of that, and the two effects can stack up.

If potassium climbs too high (a problem called hyperkalemia), you might feel muscle weakness, tingling, an odd or irregular heartbeat, or unusual tiredness. This is more of a concern with actual supplements or salt substitutes than with normal amounts of potassium from fruits and vegetables, which usually stay safe. Folks with kidney issues are at higher risk. Please check with your pharmacist or doctor before starting any potassium supplement.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Phillips, C. O., Kashani, A., Ko, D. K., Francis, G., and Krumholz, H. M. Adverse effects of combination angiotensin II receptor blockers plus angiotensin-converting enzyme inhibitors for left ventricular dysfunction: a quantitative review of data from ra DOI
  3. Malta D, Arcand J, Ravindran A, Floras V, Allard JP, Newton GE. Adequate intake of potassium does not cause hyperkalemia in hypertensive individuals taking medications that antagonize the renin angiotensin aldosterone system. Am J Clin Nutr 2016 Oct;104(4 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

Potassium Also Interacts With Other Medications

Potassium has 61 moderate known drug interactions in our database — the Captopril one above is one of them. If you take anything else, check it against the full list below.

Moderate 61 No known interaction 2,769 (incl. Captopril)
Taking anything else?

Check Another of Your Medications Against Potassium

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

From our Q&A

Questions About Potassium or Captopril

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

This page covers Potassium only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Captopril page lists 166 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 Siberian Cocklebur (major).

By severity: 6 major · 136 moderate · 24 minor.

From our pharmacist’s overview on the Captopril page

“Anyone taking captopril (Capoten), an ACE inhibitor for high blood pressure and heart failure, should treat this list with genuine care rather than a quick skim. Most of the ingredients here act on blood pressure itself, some dropping it lower than intended and others, tyramine among them, pushing it back up and working against the med…”

Reviewed by 2 · Jul 18, 2026

Open the Captopril interaction page

One more smart check

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

We hold 22,782 real supplement products containing Potassium, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Potassium. Your product may carry other ingredients that interact with Captopril too, on top of Potassium — 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 Potassium and Captopril 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 Potassium
Top 10

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

29 days ago today
Medication Captopril
Top 25%

#571 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 Potassium

What is Potassium?

  • Preventing or treating low potassium (hypokalemia)
  • Supporting healthy blood pressure
  • Muscle cramps
  • Replacing losses from diuretics or vomiting/diarrhea
  • General electrolyte balance

Potassium is an essential mineral your body needs for nerve signals, muscle function, and a steady heartbeat, and most people get enough from a balanced diet rich in fruits and vegetables. Potassium supplements can help when blood levels are truly low, but too much potassium can be dangerous, especially for people with kidney problems. Always talk with your pharmacist or doctor before taking a potassium supplement.

Read the full Potassium monograph & all interactions
Medication

About Captopril

What Is Captopril Used For?

Brand names: Capoten, Acepril

Captopril tablets are used to treat high blood pressure (hypertension), heart failure, and left ventricular dysfunction (weakened pumping function of the heart) in stable patients after a heart attack. For the heart attack indication, it helps improve survival and reduces the chance of developing full heart failure.

Captopril tablets are also used to slow the progression of diabetic nephropathy (kidney damage caused by diabetes) in people with type 1 (insulin-dependent) diabetes who have retinopathy and significant protein in their urine. It reduces the risk of the kidneys failing to the point of needing dialysis or a transplant.

See full Captopril drug information
Keep checking

Other Drugs & Potassium

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

0Major
61Moderate
0Minor
2,768No known interaction
61 Moderate 2,768 No interaction
Moderate

61 interactions

Showing 60 of 61 moderate interactions — see all 61 on the Potassium page.

No interaction 2,768 drugs checked — show the list

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

Showing the 60 most looked-up of 2,768 medications checked with no known interaction — see the full Potassium list.

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

Can you take Potassium with Captopril?
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 Potassium and Captopril 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 Captopril and Potassium?

Our pharmacists answer your medication & supplement questions — free.

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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.