Drug & supplement interaction

Ketogenic Diet + Aspirin, Caffeine, Orphenadrine

Aspirin, Caffeine, Orphenadrine brand names: Norgesic Forte, Invagesic, Invagesic Forte, Orphengesic, Norgesic, and others.

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

Ketogenic Diet has a minor interaction with Aspirin, Caffeine, Orphenadrine. Although there is some concern that the ketogenic diet might have additive effects when used with anticoagulant and antiplatelet drugs, most clinical research does not show this effect.

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

Ketogenic Diet and Aspirin, Caffeine, Orphenadrine

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

Minor

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to Aspirin, Caffeine, Orphenadrine

Aspirin, Caffeine, Orphenadrine falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Ketogenic Diet interacts with.

Although there is some concern that the ketogenic diet might have additive effects when used with anticoagulant and antiplatelet drugs, most clinical research does not show this effect.
One small observational study found that the ketogenic diet was associated with prolonged bleeding times in 16 of 51 (31%) children with epilepsy who were also on chronic anticonvulsant therapy. However, a larger observational study of 162 children with epilepsy taking chronic anticonvulsants has found that following the ketogenic diet does not increase the risk of bleeding, even in the 25 children undergoing surgery. Research in adults also has not reported changes in bleeding time.
Severity Minor Likelihood Unlikely Evidence B

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 piece that matters in your combo product: the aspirin. Aspirin thins the blood by blocking platelets from clumping. The thought is that a ketogenic diet might add to that blood-thinning effect and make bleeding or bruising slightly more likely. The good news is that most studies don't back this up. One small study in children saw longer bleeding times, but a larger study (including kids who had surgery) found no real increase in bleeding risk, and adult research hasn't shown a problem either.

So this is a minor, unlikely concern. Just keep an eye out for easy bruising, nosebleeds, or cuts that take longer to stop, and let your pharmacist or doctor know if you notice anything. The caffeine and orphenadrine pieces aren't involved here.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Melchior RW, Dreher M, Ramsey E, Savoca M, Rosenthal T. Cardiopulmonary bypass considerations for pediatric patients on the ketogenic diet. Perfusion. 2015;30(5):423-6. PubMed
  2. Dressler A, Chiara H, Benninger F, et al. Effects of the ketogenic diet on platelet counts and global coagulation tests in childhood epilepsy. Seizure. 2020;80:31-37. 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

Ketogenic Diet Also Interacts With Other Medications

Ketogenic Diet has 137 moderate, 121 minor known drug interactions in our database — the Aspirin, Caffeine, Orphenadrine one above is one of them. If you take anything else, check it against the full list below.

Moderate 137 Minor 121 No known interaction 2,572 (incl. Aspirin, Caffeine, Orphenadrine)
Taking anything else?

Check Another of Your Medications Against Ketogenic Diet

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

Everything else you take

See Every Supplement That Interacts With Aspirin, Caffeine, Orphenadrine

This page covers Ketogenic Diet only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aspirin, Caffeine, Orphenadrine page lists 350 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Danshen (major) and Ephedra (major).

By severity: 14 major · 289 moderate · 47 minor.

From our pharmacist’s overview on the Aspirin, Caffeine, Orphenadrine page

“Aspirin, caffeine, and orphenadrine (the Norgesic and Orphengesic brands) come with a supplement list that deserves real vigilance, with 14 of its 350 entries rated major. Over 200 of those ingredients can add to aspirin's effect on platelets and raise bleeding risk, another 44 stack stimulant effects on top of the caffeine, and grapef…”

Reviewed by 2 · Jul 18, 2026

Open the Aspirin, Caffeine, Orphenadrine interaction page

How much people look this up

Where Ketogenic Diet and Aspirin, Caffeine, Orphenadrine 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 Ketogenic Diet
Steady interest

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

29 days ago today
Medication Aspirin, Caffeine, Orphenadrine
Top 5%

#94 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.

Eating pattern

About Ketogenic Diet

What is Ketogenic Diet?

  • Weight loss
  • Type 2 diabetes and blood sugar control
  • Drug-resistant epilepsy (especially in children)
  • Reducing appetite
  • Athletic and metabolic interest

The ketogenic diet is a very low-carbohydrate, high-fat eating plan that shifts the body to burn fat for fuel. It has the strongest evidence as a medical therapy for hard-to-treat epilepsy and may help short-term weight loss and blood sugar, but it can be hard to sustain and is not right for everyone. Talk with a doctor or pharmacist before starting, especially if you have a medical condition or take medication.

Read the full Ketogenic Diet monograph & all interactions
Keep checking

Other Drugs & Ketogenic Diet

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

0Major
137Moderate
121Minor
2,571No known interaction
137 Moderate 121 Minor 2,571 No interaction
Moderate

137 interactions

Showing 60 of 137 moderate interactions — see all 137 on the Ketogenic Diet page.

Minor

121 interactions

Showing 60 of 121 minor interactions — see all 121 on the Ketogenic Diet page.

No interaction 2,571 drugs checked — show the list

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

Showing the 60 most looked-up of 2,571 medications checked with no known interaction — see the full Ketogenic Diet list.

See the full Ketogenic Diet interactions page
See every supplement checked against Aspirin, Caffeine, Orphenadrine, 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
Ketogenic Diet monograph › Uses, safety, and every drug interaction in one place Aspirin, Caffeine, Orphenadrine supplement interactions › Every supplement checked against Aspirin, Caffeine, Orphenadrine, ranked by severity 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

Following Ketogenic Diet While Taking Aspirin, Caffeine, Orphenadrine: Common Questions

Can you follow Ketogenic Diet while taking Aspirin, Caffeine, Orphenadrine?
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 Ketogenic Diet and Aspirin, Caffeine, Orphenadrine 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 Aspirin, Caffeine, Orphenadrine and Ketogenic Diet?

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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.