Drug & supplement interaction

Whey Protein + Clinafloxacin

Clinafloxacin brand name: Clinafloxacin.

Moderate Interaction
The bottom line Moderate

Whey Protein has a moderate interaction with Clinafloxacin. Theoretically, whey protein might decrease quinolone absorption.

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

Whey Protein and Clinafloxacin

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

Moderate

QUINOLONE ANTIBIOTICS

Why this applies to Clinafloxacin

Clinafloxacin falls under QUINOLONE ANTIBIOTICS — the group Whey Protein interacts with.

Theoretically, whey protein might decrease quinolone absorption.
Whey protein contains minerals, such as calcium, that can bind to quinolones in the gut. To avoid this interaction, advise patients to take oral quinolones at least 2 hours before or 4-6 hours after whey protein.
Severity Moderate Likelihood Probable Evidence D

Interaction 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..

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

Here's the simple version: clinafloxacin is one of the fluoroquinolone antibiotics, and these drugs don't mix well with minerals in your stomach. Whey protein carries calcium (and sometimes other minerals), which can grab onto the antibiotic in your gut and form clumps your body can't absorb well. The worry isn't a toxic buildup, it's the opposite, you may absorb less of the antibiotic, which could mean it doesn't fight your infection as strongly as it should.

This concern is based on how these drugs behave chemically, not on hard clinical proof, so think of it as a reasonable precaution rather than a red alert. The easy fix is timing: take your clinafloxacin at least 2 hours before or 4 to 6 hours after your whey protein. Your pharmacist can help you map out a schedule.

References
  1. Martindale W. Martindale the Extra Pharmacopoeia. Pharmaceutical Press, 1999.
  2. Pletz MW, Petzold P, Allen A, et al. Effect of calcium carbonate on bioavailability of orally administered gemifloxacin. Antimicrob Agents Chemother 2003;47:2158-60.. 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

Whey Protein Also Interacts With Other Medications

Whey Protein has 5 major, 47 moderate known drug interactions in our database — the Clinafloxacin 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 Whey Protein

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

From our Q&A

Questions About Whey Protein or Clinafloxacin

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

This page covers Whey Protein only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Clinafloxacin page lists 87 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Apple (major), Grapefruit (major), Sweet Orange (major) and Bacillus Coagulans (moderate).

By severity: 4 major · 62 moderate · 21 minor.

From our pharmacist’s overview on the Clinafloxacin page

“If you have been prescribed clinafloxacin, a quinolone antibiotic, start with the four interactions rated major, because they all do the same thing: apple, grapefruit, and orange juice, along with activated charcoal, can sharply cut how much of the drug you absorb, and an antibiotic that never reaches your bloodstream cannot clear the…”

Reviewed by 2 · Jul 18, 2026

Open the Clinafloxacin interaction page

One more smart check

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

We hold 1,276 real supplement products containing Whey Protein, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Whey Protein. Your product may carry other ingredients that interact with Clinafloxacin too, on top of Whey Protein — 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 Whey Protein and Clinafloxacin 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 Whey Protein
Top 10%

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

29 days ago today
Medication Clinafloxacin
Top half

#865 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 Whey Protein

What is Whey Protein?

Whey Protein
  • Muscle building and recovery
  • Increasing daily protein intake
  • Weight management
  • Sports nutrition
  • Meal replacement

Whey protein is a high-quality, complete protein made from cow's milk that can help people meet protein needs and support muscle growth when combined with exercise. It is generally safe for most healthy adults, but people with milk allergies should avoid it, and those with kidney disease or who are lactose intolerant should use caution.

Read the full Whey Protein monograph & all interactions
Keep checking

Other Drugs & Whey Protein

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

5Major
47Moderate
0Minor
2,777No known interaction
Major

5 interactions

Moderate

47 interactions

No interaction 2,777 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 Whey Protein and Clinafloxacin Together: Common Questions

Can you take Whey Protein with Clinafloxacin?
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 Whey Protein and Clinafloxacin 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 Clinafloxacin and Whey Protein?

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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.