Drug & supplement interaction

Acerola + Thiotepa

Thiotepa brand names: Thioplex, Tepadina.

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

Acerola has a moderate interaction with Thiotepa. Theoretically, the antioxidant effects of acerola might reduce the effectiveness of alkylating agents.

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

Acerola and Thiotepa

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

Moderate

ALKYLATING AGENTS

Why this applies to Thiotepa

Thiotepa falls under ALKYLATING AGENTS — the group Acerola interacts with.

Theoretically, the antioxidant effects of acerola might reduce the effectiveness of alkylating agents.
Acerola contains vitamin C, an antioxidant. There is concern that antioxidants might reduce the activity of chemotherapy drugs that generate free radicals, such as alkylating agents. In contrast, other researchers theorize that antioxidants might make alkylating chemotherapy more effective by reducing oxidative stress that could interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effect, if any, antioxidants such as vitamin C have on 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 honest picture with acerola and thiotepa. Acerola is basically a concentrated source of vitamin C, which is an antioxidant. Thiotepa is a chemo drug (an alkylating agent) that works partly by causing oxidative stress inside cancer cells. The theoretical worry is that piling on antioxidants like vitamin C could blunt that effect and make the chemo work less well. Honestly, though, the science here is mixed. Some researchers think antioxidants might even help. We just don't have solid human studies to say for sure.

Because this is only a theory and thiotepa is serious cancer treatment, please don't start or stop acerola or any vitamin C supplement on your own. Food amounts of the fruit are unlikely to be a problem, but talk with your oncologist or pharmacist before using concentrated supplements during treatment.

Contact Dr. Brian directly if you have additional questions on this interaction
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 Thiotepa one above is one of them. If you take anything else, check it against the full list below.

Moderate 38 Minor 89 No known interaction 2,703 (incl. Thiotepa)
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 Thiotepa

This page covers Acerola only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Thiotepa page lists 146 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 102 moderate · 41 minor.

From our pharmacist’s overview on the Thiotepa page

“Thiotepa (Thioplex, Tepadina) is chemotherapy, given for several cancers and to prepare patients for stem cell transplant, so its 146 supplement interactions make up a list to respect rather than skim. Three carry a major rating: grapefruit, St.”

Reviewed by 2 · Jul 18, 2026

Open the Thiotepa 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 Thiotepa 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 Thiotepa 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 Thiotepa
Steady interest

#1,995 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 Thiotepa Injection

What Is Thiotepa Injection Used For?

Brand names: Thioplex, Tepadina

Tepadina (thiotepa) injection is used for several purposes. It treats adenocarcinoma (a type of cancer) of the breast or ovary. It is also used to control malignant effusions — abnormal fluid buildup in body cavities caused by cancer spreading to those areas. For bladder cancer, Tepadina treats superficial papillary carcinoma of the urinary bladder.

Tepadina is also used in pediatric patients with class 3 beta-thalassemia (a severe inherited blood disorder). In those patients, it is given as part of a preparative regimen — a conditioning treatment to reduce the risk of graft rejection before an allogeneic stem cell transplant (a transplant using donor stem cells), alongside the chemotherapy drugs busulfan and cyclophosphamide.

See full Thiotepa Injection 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
38 Moderate 89 Minor 2,702 No 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

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 Thiotepa, 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 Thiotepa supplement interactions › Every supplement checked against Thiotepa, ranked by severity Thiotepa Injection 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 Thiotepa Together: Common Questions

Can you take Acerola with Thiotepa?
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 Thiotepa 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 Thiotepa 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.