Drug & supplement interaction

Acerola + Warfarin

Warfarin brand name: Warfarin.

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

Acerola has a minor interaction with Warfarin. Theoretically, acerola might reduce the effectiveness of warfarin; however, its vitamin C content is likely too low to produce clinically significant effects.

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

Acerola and Warfarin

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

Minor

WARFARIN (Coumadin)

Theoretically, acerola might reduce the effectiveness of warfarin; however, its vitamin C content is likely too low to produce clinically significant effects.
Acerola contains vitamin C. High doses of vitamin C may reduce the response to warfarin, possibly by causing diarrhea and reducing warfarin absorption. This occurred in two people who took up to 16 grams daily of vitamin C, and resulted in decreased prothrombin time. Lower doses of 5-10 grams daily of vitamin C can also reduce warfarin absorption, but this does not seem to be clinically significant. The vitamin C content of acerola is typically about 2000 mg per 100 grams. Thus, a clinically significant interaction between acerola and warfarin is unlikely.
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 short version: acerola is basically a vitamin C powerhouse, and the worry on file is that very high doses of vitamin C might slightly lower how much warfarin your body absorbs. In theory that could make warfarin a touch less effective, which for a blood thinner means your clot protection could dip. But honestly, this is a weak, theory-based concern. The cases behind it involved people taking around 16 grams of vitamin C a day, far more than you'd get from eating acerola.

Because warfarin is a narrow-window drug where small swings matter, I never wave it off completely. If you plan to use a concentrated acerola supplement (not just the fruit), keep your INR checks steady and let your pharmacist or doctor know first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Rosenthal G. Interaction of ascorbic acid and warfarin. JAMA 1971;215:1671. DOI
  2. Hume R, Johnstone JM, Weyers E. Interaction of ascorbic acid and warfarin. JAMA 1972;219:1479. DOI
  3. Smith EC, Skalski RJ, Johnson GC, Rossi GV. Interaction of ascorbic acid and warfarin. JAMA 1972;221:1166. DOI
  4. Feetam CL, Leach RH, Meynell MJ. Lack of a clinically important interaction between warfarin and ascorbic acid. Toxicol Appl Pharmacol 1975;31:544-7. PubMed
  5. Weintraub M, Griner PF. Warfarin and ascorbic acid: lack of evidence for a drug interaction. Toxicol Appl Pharmacol 1974;28:53-6. 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

Acerola Also Interacts With Other Medications

Acerola has 39 moderate, 88 minor known drug interactions in our database — the Warfarin one above is one of them. If you take anything else, check it against the full list below.

Moderate 39 Minor 88 No known interaction 2,703 (incl. Warfarin)
Taking anything else?

Check Another of Your Medications Against Acerola

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

From our Q&A

Questions About Acerola or Warfarin

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

This page covers Acerola only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Warfarin page lists 361 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Alfalfa (major), American Ginseng (major), Beer (major) and Cannabis (major).

By severity: 16 major · 301 moderate · 44 minor.

From our pharmacist’s overview on the Warfarin page

“People take warfarin to prevent dangerous clots, and many are the same people reaching for glucosamine for sore joints or a multivitamin containing vitamin K, which makes this a list that deserves genuine respect. Of the 361 supplements on file for warfarin, 16 carry a major rating, and the danger runs in both directions: some add to w…”

Reviewed by 2 · Jul 18, 2026

Open the Warfarin interaction page

One more smart check

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

We hold 2,642 real supplement products containing Acerola, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Acerola. Your product may carry other ingredients that interact with Warfarin too, on top of Acerola — 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 Acerola and Warfarin 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 Acerola
Top 10%

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

29 days ago today
Medication Warfarin
Top 10

#4 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 Acerola

What is Acerola?

Acerola
  • Vitamin C source
  • Immune support
  • Antioxidant support
  • General wellness
  • Skin health

Acerola is a small tropical fruit prized for its very high natural vitamin C content, and it is mostly used as a food-based source of vitamin C and antioxidants. While vitamin C itself has well-known roles in the body, strong human studies showing that acerola specifically treats or prevents disease are limited. It is generally considered safe in food amounts, but check with your pharmacist or doctor before using concentrated supplements.

Read the full Acerola monograph & all interactions
Medication

About Warfarin

What Is Warfarin Used For?

Brand name: Warfarin

Warfarin sodium tablets and Jantoven tablets are both used to prevent and treat venous thrombosis (blood clots in the veins) and pulmonary embolism (a clot in the lungs). They are also used to prevent clot-related complications in people with atrial fibrillation (an irregular heart rhythm) or who have had a heart valve replaced.

In people who have had a heart attack, warfarin is used to reduce the risk of death, another heart attack, stroke, or other clotting events. It does not dissolve an existing clot, but it helps prevent the clot from growing and stops new dangerous clots from forming.

See full Warfarin drug information
Keep checking

Other Drugs & Acerola

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

0Major
39Moderate
88Minor
2,702No known interaction
39 Moderate 88 Minor 2,702 No interaction
Moderate

39 interactions

Minor

88 interactions

Showing 60 of 88 minor interactions — see all 88 on the Acerola page.

No interaction 2,702 drugs checked — show the list

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

Showing the 60 most looked-up of 2,702 medications checked with no known interaction — see the full Acerola list.

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

Can you take Acerola with Warfarin?
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 Acerola and Warfarin 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 Warfarin and Acerola?

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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.