Drug & supplement interaction

Potassium + Losartan Potassium

Losartan Potassium brand name: Cozaar.

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

Potassium has a moderate interaction with Losartan Potassium. Using ARBs 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 Losartan Potassium

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

Moderate

ANGIOTENSIN RECEPTOR BLOCKERS (ARBs)

Why this applies to Losartan Potassium

Losartan Potassium falls under ANGIOTENSIN RECEPTOR BLOCKERS (ARBs) — the group Potassium interacts with.

Using ARBs with high doses of potassium increases the risk of hyperkalemia.
ARBs 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 something worth knowing about losartan (Cozaar): it works by blocking a hormone system that normally helps your kidneys flush out extra potassium. So while you're on it, your body naturally holds onto a bit more potassium than usual. Notice that even the drug's full name is losartan potassium, though that built-in amount is tiny and not the concern here.

The real issue is adding a potassium supplement on top. Together, they can push your potassium too high, a problem called hyperkalemia. That can cause muscle weakness, tingling, or in serious cases an irregular heartbeat. The good news: getting potassium from a normal diet of fruits and vegetables is generally fine. Before starting any potassium pill or a salt substitute, please check with your pharmacist or doctor first, since this often needs a simple blood test.

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 Losartan Potassium 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. Losartan Potassium)
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 Losartan Potassium

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 Losartan Potassium, 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 Losartan Potassium

This page covers Potassium only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Losartan Potassium page lists 253 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), Grapefruit (major) and St. John's Wort (major).

By severity: 6 major · 205 moderate · 42 minor.

From our pharmacist’s overview on the Losartan Potassium page

“Losartan potassium (Cozaar) treats high blood pressure, and this is a list to respect, because six of its 253 supplement interactions carry a major rating. Most entries do one of two things.”

Reviewed by 2 · Jul 18, 2026

Open the Losartan Potassium 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 Losartan Potassium 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 Losartan Potassium 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

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

29 days ago today
Medication Losartan Potassium
Top 10

#7 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 Losartan

What Is Losartan Used For?

Brand name: Cozaar

Losartan tablets — available as branded Cozaar and several generic products — are used to treat high blood pressure (hypertension) in adults and children 6 years and older. Lowering blood pressure reduces the risk of strokes and heart attacks. Losartan tablets are also used to reduce the risk of stroke in people with high blood pressure who also have left ventricular hypertrophy (an enlarged left side of the heart). Note: evidence suggests this stroke-risk benefit may not apply to Black patients.

Losartan tablets are additionally approved to protect the kidneys in people with type 2 diabetes, high blood pressure, and signs of kidney damage (diabetic nephropathy). Arbli, the oral suspension form, shares these same approved uses.

See full Losartan 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 Losartan Potassium, 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 Losartan Potassium supplement interactions › Every supplement checked against Losartan Potassium, ranked by severity Losartan 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 Losartan Potassium Together: Common Questions

Can you take Potassium with Losartan Potassium?
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 Losartan Potassium 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 Losartan Potassium and Potassium?

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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.