Drug & supplement interaction

Hemp + Aspirin, Caffeine, Codeine Phosphate

Aspirin, Caffeine, Codeine Phosphate brand name: Anacin w/ Codeine.

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

Aspirin, Caffeine, Codeine Phosphate falls into 3 drug categories that Hemp can interact with; the most serious is rated minor. Theoretically, hemp seed might increase the risk of bleeding when used concomitantly with anticoagulant/antiplatelet drugs.

Read the full interaction report
SeverityMinor
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Hemp and Aspirin, Caffeine, Codeine Phosphate

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Hemp interacts with whole categories of medication. Aspirin, Caffeine, Codeine Phosphate falls into 3 of those categories, so it can interact with Hemp in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Minor).

Minor

ANTICOAGULANT/ANTIPLATELET DRUGS

1 of 3

Why this applies to Aspirin, Caffeine, Codeine Phosphate

Aspirin, Caffeine, Codeine Phosphate falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Hemp interacts with.

Theoretically, hemp seed might increase the risk of bleeding when used concomitantly with anticoagulant/antiplatelet drugs.
In animal research, hemp seed at 5% of the diet inhibits platelet aggregation in vitro. However, in human research, taking hemp seed oil 2 grams daily for 12 weeks does not inhibit the aggregation of platelets in vitro.
Severity Minor 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 gist: this combination medicine contains aspirin, which already thins the blood a bit by keeping platelets from clumping. The concern with hemp is that it might add to that blood-thinning effect, theoretically raising the chance of things like easy bruising, nosebleeds, or stomach irritation and bleeding.

Honestly though, this is a pretty weak worry. The signal comes from animal and lab studies, and when actual people took 2 grams of hemp seed oil daily for 12 weeks, it did not measurably affect their platelets. So normal food amounts of hemp seeds are very unlikely to cause trouble. If you use concentrated hemp supplements regularly, just mention it to your pharmacist or doctor so they can keep an eye out.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Kaul N, Kreml R, Austria JA, et al. A comparison of fish oil, flaxseed oil and hempseed oil supplementation on selected parameters of cardiovascular health in healthy volunteers. J Am Coll Nutr 2008;27:51-8. PubMed
  2. Richard MN, Ganguly R, Steigerwald SN, Al-Khalifa A, Pierce GN. Dietary hempseed reduces platelet aggregation. J Thromb Haemost. 2007;5(2):424-5. PubMed
Minor

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

2 of 3

Aspirin, Caffeine, Codeine Phosphate also falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES.

Theoretically, hemp might decrease the levels and clinical effects of CYP1A2 substrates.
In vitro research shows that hemp induces CYP1A2 enzymes.
Severity Minor 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

This combination pill has three active parts, but the one tied to this interaction is the caffeine, which your body clears using an enzyme called CYP1A2. Lab studies suggest hemp may speed that enzyme up a bit. If that happened in real life, your body might break down caffeine a little faster, so you could feel slightly less of its perk and alertness boost.

Honestly, I wouldn't lose sleep over this one. The evidence is only from test-tube and animal studies, not people, and it's rated as minor. The aspirin (for pain) and codeine (for pain relief) parts aren't really affected here. Still, if you take hemp regularly and notice any change, just check in with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Haron MH, Dale O, Martin K, et al. Evaluation of the Herb-Drug Interaction Potential of Commonly Used Botanicals on the US Market with Regard to PXR- and AhR-Mediated Influences on CYP3A4 and CYP1A2. J Diet Suppl 2022. PubMed
Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

3 of 3

Aspirin, Caffeine, Codeine Phosphate also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, hemp might decrease the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that hemp induces CYP3A4 enzymes.
Severity Minor 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 wrinkle with this combo pill: the codeine part is actually a prodrug. Your body has to convert it into morphine before you feel any pain relief, and some of that processing involves CYP3A4. Lab studies (not human studies) hint that hemp might rev up CYP3A4 a bit. In theory, speeding up that enzyme could shift how codeine is handled, possibly trimming the pain relief you get.

Honestly though, this is very weak evidence, just test-tube data, so I wouldn't lose sleep over it. Eating hemp seeds or hemp oil as food is unlikely to cause any real problem. If you're taking concentrated hemp supplements and notice your pain relief slipping, mention it to your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Haron MH, Dale O, Martin K, et al. Evaluation of the Herb-Drug Interaction Potential of Commonly Used Botanicals on the US Market with Regard to PXR- and AhR-Mediated Influences on CYP3A4 and CYP1A2. J Diet Suppl 2022. 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

Hemp Also Interacts With Other Medications

Hemp has 41 moderate, 896 minor known drug interactions in our database — the Aspirin, Caffeine, Codeine Phosphate one above is among them. If you take anything else, check it against the full list below.

Moderate 41 Minor 896 No known interaction 1,893 (incl. Aspirin, Caffeine, Codeine Phosphate)
Taking anything else?

Check Another of Your Medications Against Hemp

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

Everything else you take

See Every Supplement That Interacts With Aspirin, Caffeine, Codeine Phosphate

This page covers Hemp only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aspirin, Caffeine, Codeine Phosphate page lists 398 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Asarabacca (major), Beer (major) and Danshen (major).

By severity: 17 major · 334 moderate · 47 minor.

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

“Anacin with Codeine combines aspirin, caffeine, and codeine, and each of the three picks up its own supplement problems, so this is a list worth real caution. Just over half of the 398 ingredients here, 202 of them, can add to aspirin's blood-thinning action and raise bleeding risk.”

Reviewed by 2 · Jul 18, 2026

Open the Aspirin, Caffeine, Codeine Phosphate interaction page

One more smart check

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

We hold 720 real supplement products containing Hemp, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Hemp. Your product may carry other ingredients that interact with Aspirin, Caffeine, Codeine Phosphate too, on top of Hemp — 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 Hemp and Aspirin, Caffeine, Codeine Phosphate 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 Hemp
Top 25%

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

29 days ago today
Medication Aspirin, Caffeine, Codeine Phosphate
Top half

#1,392 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 Hemp

What is Hemp?

Hemp
  • Plant-based protein source
  • Heart health support
  • Skin and hair health
  • Reducing inflammation
  • General nutrition (omega fatty acids)

Hemp seeds and hemp seed oil are nutritious foods rich in protein, fiber, and healthy omega-3 and omega-6 fatty acids, and they are generally safe for most people as part of the diet. While the nutrition is real, strong human evidence that hemp supplements treat specific medical conditions is limited. Talk with your pharmacist or doctor before using hemp products for a health concern, especially if you are pregnant or breastfeeding.

Read the full Hemp monograph & all interactions
Keep checking

Other Drugs & Hemp

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

0Major
41Moderate
896Minor
1,892No known interaction
41 Moderate 896 Minor 1,892 No interaction
Moderate

41 interactions

Minor

896 interactions

Showing 60 of 896 minor interactions — see all 896 on the Hemp page.

No interaction 1,892 drugs checked — show the list

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

Showing the 60 most looked-up of 1,892 medications checked with no known interaction — see the full Hemp list.

See the full Hemp interactions page
See every supplement checked against Aspirin, Caffeine, Codeine Phosphate, 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
Hemp monograph › Uses, safety, and every drug interaction in one place Aspirin, Caffeine, Codeine Phosphate supplement interactions › Every supplement checked against Aspirin, Caffeine, Codeine Phosphate, 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

Taking Hemp and Aspirin, Caffeine, Codeine Phosphate Together: Common Questions

Can you take Hemp with Aspirin, Caffeine, Codeine Phosphate?
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.
Why are there 3 interactions listed for Hemp and Aspirin, Caffeine, Codeine Phosphate?
Aspirin, Caffeine, Codeine Phosphate belongs to more than one drug category, and Hemp interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Hemp and Aspirin, Caffeine, Codeine Phosphate 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

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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.