Drug & supplement interaction

Acerola + Valrubicin

Valrubicin brand name: Valstar.

Moderate Interaction
The bottom line Moderate

Acerola has a moderate interaction with Valrubicin. Theoretically, the antioxidant effects of acerola might reduce the effectiveness of antitumor antibiotics.

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

Acerola and Valrubicin

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

Moderate

ANTITUMOR ANTIBIOTICS

Why this applies to Valrubicin

Valrubicin falls under ANTITUMOR ANTIBIOTICS — the group Acerola interacts with.

Theoretically, the antioxidant effects of acerola might reduce the effectiveness of antitumor antibiotics.
Acerola contains vitamin C, an antioxidant. There is concern that antioxidants might reduce the activity of chemotherapy drugs that generate free radicals, such as antitumor antibiotics. In contrast, other researchers theorize that antioxidants might make antitumor antibiotic chemotherapy more effective by reducing oxidative stress that could interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effects, if any, antioxidants such as vitamin C have on antitumor antibiotic chemotherapy.
Severity Moderate Likelihood Possible Evidence D

Interaction 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.

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

Here's the thinking behind this one. Valrubicin (Valstar) is an anthracycline-type chemo medicine that's placed right into the bladder to fight cancer cells, and part of how these drugs work is by generating free radicals that damage and kill those cells. Acerola is loaded with vitamin C, a strong antioxidant, and the theory is that mopping up free radicals might blunt how well the chemo works. So the concern here is about possibly weakening the treatment, not adding side effects.

I want to be honest though: this is purely theoretical, based on how the drugs work on paper, not on solid human studies. Some researchers even argue antioxidants could help. Since this is serious cancer therapy, please don't add concentrated acerola or vitamin C supplements without first clearing it with your oncologist or pharmacist.

References
  1. Labriola D, Livingston R. Possible interactions between dietary antioxidants and chemotherapy. Oncology 1999;13:1003-8.
  2. Prasad KN. Rationale for using high-dose multiple dietary antioxidants as an adjunct to radiation therapy and chemotherapy. J Nutr 2004;134:3182S-3S. PubMed
  3. Conklin KA. Cancer chemotherapy and antioxidants. J Nutr 2004;134:3201S-3204S. 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 38 moderate, 89 minor known drug interactions in our database — the Valrubicin one above is one of them. If you take anything else, check it against the full list below.

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.

Everything else you take

See Every Supplement That Interacts With Valrubicin

This page covers Acerola only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Valrubicin page lists 24 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Alpha-lipoic Acid (moderate), Coffee Charcoal (moderate), European Mandrake (moderate) and Glucomannan (moderate).

By severity: 1 major · 14 moderate · 9 minor.

From our pharmacist’s overview on the Valrubicin page

“Activated charcoal is the supplement I would flag hardest for anyone receiving valrubicin (Valstar), a chemotherapy instilled directly into the bladder for cancer. It carries the only major rating among the 24 ingredients on this page, since charcoal can bind and clear many drugs from the body even when they are not swallowed.”

Reviewed by 2 · Jul 18, 2026

Open the Valrubicin 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 Valrubicin 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 Valrubicin 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%

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

29 days ago today
Medication Valrubicin
Steady interest

#2,697 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 Valrubicin Intravesical

What Is Valrubicin Intravesical Used For?

Brand name: Valstar

Valrubicin Intravesical Solution is used to treat BCG-refractory carcinoma in situ (CIS) of the urinary bladder — meaning bladder cancer that has not responded to BCG immunotherapy. It is given directly into the bladder (intravesically) rather than taken by mouth or injected into the bloodstream.

This treatment is specifically for patients whose cancer has not responded to BCG and for whom having the bladder surgically removed (cystectomy) right away would carry unacceptable health risks.

See full Valrubicin Intravesical 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
38Moderate
89Minor
2,702No known interaction
Moderate

38 interactions

Minor

89 interactions

Showing 60 of 89 minor interactions — see all 89 on the Acerola page.

No interaction 2,702 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Acerola and Valrubicin Together: Common Questions

Can you take Acerola with Valrubicin?
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 Acerola and Valrubicin 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 Valrubicin 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.