Drug & supplement interaction

Selenium + Cisplatin

Cisplatin brand name: Platinol-AQ.

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

Selenium has a moderate interaction with Cisplatin. Theoretically, selenium supplementation may reduce the effectiveness of immunosuppressant therapy.

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

Selenium and Cisplatin

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

Moderate

IMMUNOSUPPRESSANTS

Why this applies to Cisplatin

Cisplatin falls under IMMUNOSUPPRESSANTS — the group Selenium interacts with.

Theoretically, selenium supplementation may reduce the effectiveness of immunosuppressant therapy.
In vitro research and preliminary clinical evidence suggests that selenium may stimulate the immune system.
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 key thing to know: cisplatin isn't really a typical immunosuppressant in the way that label suggests. It's a platinum-based chemotherapy drug that works as an antioxidant's enemy, generating cell-damaging free radicals to kill cancer cells. Because selenium is an antioxidant mineral, the worry on file is that high-dose selenium could, in theory, blunt some of that oxidative damage and make the chemo work a little less effectively.

I want to be honest with you though: this concern comes only from lab and animal studies, so it's theoretical and not well proven in people. Normal dietary amounts of selenium are very unlikely to be an issue. The real risk is taking concentrated selenium supplements during treatment. Please don't start, stop, or change anything on your own. Check with your oncology team or pharmacist first so they can weigh in for your specific plan.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Peretz, A., Neve, J., Desmedt, J., Duchateau, J., Dramaix, M., and Famaey, J. P. Lymphocyte response is enhanced by supplementation of elderly subjects with selenium-enriched yeast. Am.J Clin.Nutr. 1991;53(5):1323-1328. PubMed
  2. Kiremidjian-Schumacher, L., Roy, M., Wishe, H. I., Cohen, M. W., and Stotzky, G. Supplementation with selenium and human immune cell functions. II. Effect on cytotoxic lymphocytes and natural killer cells. Biol.Trace Elem.Res. 1994;41(1-2):115-127. 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

Selenium Also Interacts With Other Medications

Selenium has 287 moderate, 33 minor known drug interactions in our database — the Cisplatin one above is one of them. If you take anything else, check it against the full list below.

Moderate 287 Minor 33 No known interaction 2,510 (incl. Cisplatin)
Taking anything else?

Check Another of Your Medications Against Selenium

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

From our Q&A

Questions About Selenium or Cisplatin

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

This page covers Selenium only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Cisplatin page lists 90 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Siberian Cocklebur (major), Acerola (moderate) and Active Hexose Correlated Compound (ahcc) (moderate).

By severity: 3 major · 75 moderate · 12 minor.

From our pharmacist’s overview on the Cisplatin page

“Kidney damage is the risk I would flag first for anyone receiving cisplatin (Platinol-AQ). Cisplatin is a chemotherapy drug that already stresses the kidneys, and two of the three major-rated interactions on this list, Siberian cocklebur and asarabacca, involve herbs that can injure the kidneys on their own, stacking harm on an organ t…”

Reviewed by 2 · Jul 18, 2026

Open the Cisplatin interaction page

One more smart check

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

We hold 16,942 real supplement products containing Selenium, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Selenium. Your product may carry other ingredients that interact with Cisplatin too, on top of Selenium — 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 Selenium and Cisplatin 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 Selenium
Top 1%

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

29 days ago today
Medication Cisplatin
Top half

#1,242 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 Selenium

What is Selenium?

  • Thyroid health support
  • Antioxidant support
  • Immune support
  • General nutrient supplementation
  • Reproductive/fertility support

Selenium is an essential trace mineral your body needs in small amounts for thyroid function, antioxidant defense, and immune health. Most people who eat a varied diet get enough, and supplements are mainly useful for those who are deficient. Because too much selenium can be toxic, stick to recommended amounts and check with your pharmacist or doctor before supplementing.

Read the full Selenium monograph & all interactions
Medication

About Cisplatin Injection

What Is Cisplatin Injection Used For?

Brand name: Platinol-AQ

Cisplatin Injection is used to treat three types of cancer. For metastatic testicular tumors and metastatic ovarian tumors, it is used as part of combination chemotherapy — alongside other approved cancer medicines — in patients who have already had surgery and/or radiation therapy. For metastatic ovarian tumors, it can also be used alone as a second-line treatment when standard chemotherapy has stopped working and cisplatin has not been tried before.

For advanced bladder cancer (specifically transitional cell bladder cancer) that can no longer be treated with surgery or radiation, Cisplatin Injection is used as a single agent.

See full Cisplatin Injection drug information
Keep checking

Other Drugs & Selenium

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

0Major
287Moderate
33Minor
2,509No known interaction
287 Moderate 33 Minor 2,509 No interaction
Moderate

287 interactions

Showing 60 of 287 moderate interactions — see all 287 on the Selenium page.

Minor

33 interactions

No interaction 2,509 drugs checked — show the list

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

Showing the 60 most looked-up of 2,509 medications checked with no known interaction — see the full Selenium list.

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

Can you take Selenium with Cisplatin?
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 Selenium and Cisplatin 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 Cisplatin and Selenium?

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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.