Drug & supplement interaction

Black Currant + Losartan Potassium

Losartan Potassium brand name: Cozaar.

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 Black Currant and Losartan Potassium 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 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

Black Currant and Losartan Potassium

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 Losartan Potassium and Black Currant 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.

Black Currant safety at a glance

Black Currant overall Use caution The berry is safe as a food, but concentrated supplements are less studied and should be used carefully.
Pregnancy Use caution Eating the berry in food amounts is likely fine, but supplements lack safety data, so check with your doctor first.
Breastfeeding Use caution Food amounts are probably okay, but there is not enough information on concentrated supplements, so use caution.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Losartan Potassium and Black Currant? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Losartan Potassium

Interactions in our licensed database are recorded against drug classes, not just single drug names. Losartan Potassium is filed under 7 classifications — including angiotensin receptor blockers (arbs), cytochrome p450 2c9 (cyp2c9) substrates, antihypertensive drugs. Black Currant has documented interactions with 2 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate) and phenothiazines (moderate) — and none of Losartan Potassium’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

Black Currant Does Interact With Other Medications

Black Currant has 140 moderate known drug interactions in our database — Losartan Potassium isn’t one of them. If you take anything else, check it against the full list below.

Moderate 140 No known interaction 2,690 (incl. Losartan Potassium)
Taking anything else?

Check Another of Your Medications Against Black Currant

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

What to actually watch for

No Interaction Found — But Data Suggests Black Currant and Losartan Potassium May Share a Side Effect

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.

  • Diarrhea reported in 5.8% of FDA reports for Losartan Potassium Additional detail

    Black Currant

    “Of 2154 patients with hyperlipidemia taking black currant seed oil 1.8 grams twice daily for 6 weeks, 8 reports of mild diarrhea were considered related to the supplement. These adverse reactions were reported 2-10 days after beginning treatment with black currant seed oil.”

    Black Currant · Natural Medicines adverse-effect record, reported in diarrhea.

    1 source cited
    1. 17638. Fa-lin Z, Zhen-yu W, Yan H, et al. Efficacy of blackcurrant oil soft capsule, a Chinese herbal drug, in hyperlipidemia treatment. Phytother Res 2010;24 Suppl 2:S209-13. PubMed

    Losartan Potassium

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

Effects for Losartan Potassium come from the ADVERSE REACTIONS section of its FDA label; effects for Black Currant come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 89,498 voluntary FDA FAERS reports for Losartan Potassium 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.

Overlapping uses

What Losartan Potassium Is Prescribed For, and What Black Currant Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Losartan Potassium is a prescription medicine with approved uses on its FDA label. Black Currant is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Losartan Potassium is prescribed for: 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.

Read the rest of what Losartan Potassium is prescribed for

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.

Black Currant has been studied for:

  • Hypertension studied, not established Black Currant has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Black Currant for hypertension

    It is unclear if oral black currant seed oil is beneficial in patients with hypertension.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Losartan Potassium on your own; if you are taking Black Currant for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Black Currant 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 Black Currant 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 Black Currant 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 Black Currant as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,265 real supplement products containing Black Currant, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Black Currant. Even though Black Currant itself has no known interaction with Losartan Potassium, 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 Black Currant 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 Black Currant
Top 25%

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

29 days ago today
Medication Losartan Potassium
Top 10

#6 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 Black Currant reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Black Currant and Losartan Potassium 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 Black Currant

What is Black Currant?

Black Currant
  • Dry eyes and eye strain
  • Joint pain and inflammation
  • Immune and general wellness support
  • Cardiovascular health
  • Skin conditions (such as dry skin or eczema)

Black currant is a nutritious berry that is rich in vitamin C and antioxidants, and its seed oil contains the omega-6 fatty acid GLA. While it is enjoyed safely as a food and is popular as a supplement, solid human evidence for most health claims is still limited. Talk with your pharmacist or doctor before using concentrated supplements, especially if you are pregnant, nursing, or have a medical condition.

Ribes nigrum · Grossulariaceae · Berries (fruit), seeds (seed oil), and leaves · Whole berries, juice, capsules, seed oil softgels, dried leaf for tea, extracts

An interaction check asks whether these two react with each other — it does not ask whether Black Currant is a good idea for someone in your situation. Here is what our Black Currant record says about it on its own.

Black Currant: dosing

There is no official standardized dose for black currant supplements. The right amount can vary depending on the form (berry, juice, seed oil, or leaf) and the product's strength.Because doses are not well established, the safest approach is to follow the directions on the product label and not exceed them.

From our Black Currant monograph — the full record covers uses, side effects and every documented interaction.

Read the full Black Currant 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.

Most-Reported Side Effects for Losartan Potassium

From FAERS, the FDA’s public side-effect reporting system (89,498 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 6,464 reports
Nausea 5,301 reports
Diarrhea 5,184 reports
Dyspnea 4,689 reports
Dizziness 4,429 reports
See full Losartan drug information
Keep checking

Other Drugs & Black Currant

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

0Major
140Moderate
0Minor
2,689No known interaction
140 Moderate 2,689 No interaction
Moderate

140 interactions

Showing 60 of 140 moderate interactions — see all 140 on the Black Currant page.

No interaction 2,689 drugs checked — show the list

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

Showing the 60 most looked-up of 2,689 medications checked with no known interaction — see the full Black Currant list.

See the full Black Currant interactions page
See every supplement checked against Losartan Potassium, ranked by severity
Evidence & sources

Black Currant References

The 6 references that drive our Black Currant 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. Guivernau M, Meza N, Barja P, Roman O. Clinical and experimental study on the long-term effect of dietary gamma-linolenic acid on plasma lipids, platelet aggregation, thromboxane formation, and prostacyclin production. Prostaglandins Leukot Essent Fatty A PubMed
  2. Fa-lin Z, Zhen-yu W, Yan H, et al. Efficacy of blackcurrant oil soft capsule, a Chinese herbal drug, in hyperlipidemia treatment. Phytother Res 2010;24 Suppl 2:S209-13. PubMed
  3. Holman CP and Bell AF. A trial of evening primrose oil in the treatment of chronic schizophrenia. J Orhtomolecular Psych 1983;12:302-304.
  4. Vaddadi KS. The use of gamma-linolenic acid and linoleic acid to differentiate between temporal lobe epilepsy and schizophrenia. Prostaglandins Med 1981;6(4):375-379. PubMed
  5. Norred, C. L. and Brinker, F. Potential coagulation effects of preoperative complementary and alternative medicines. Alt Ther 2001;7(6):58-67.
  6. Puri BK. The safety of evening primrose oil in epilepsy. Prostaglandins Leukotrienes Essential Fatty Acids 2007;77:101-3. PubMed

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 Black Currant and Losartan Potassium Together: Common Questions

Is it safe to take Black Currant with Losartan Potassium?
We do not list a known interaction between Black Currant and Losartan Potassium. 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 Black Currant and Losartan Potassium have any of the same side effects?
Yes — our sources link each of them separately to one 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.
Are Black Currant and Losartan Potassium used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Black Currant in each. That is a conversation for your prescriber, especially if Losartan Potassium is being adjusted to a target.
How was the Black Currant and Losartan Potassium combination checked?
Interactions in our licensed database are recorded against drug classes. Losartan Potassium is filed under 7 classifications, and Black Currant has documented interactions with 2 drug classes — none of Losartan Potassium'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 Black Currant interact with any other medications?
Yes. Black Currant has 140 documented drug interactions in our database — Losartan Potassium 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 Losartan Potassium interact with any supplements?
Yes. Losartan Potassium has documented interactions with 253 supplements in our database — Black Currant is not one of them. The Losartan Potassium 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

Black Currant monograph Uses, safety profile, and every drug interaction in one place Losartan drug information The full plain-English guide to this medication Losartan Potassium supplement interactions Every supplement checked against Losartan Potassium, 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 6 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Losartan Potassium and Black Currant?

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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.