Drug & supplement interaction

Wintergreen + Aspirin, Caffeine, Dihydrocodeine Bitartrate

Aspirin, Caffeine, Dihydrocodeine Bitartrate brand name: Synalgos DC.

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

Wintergreen has a moderate interaction with Aspirin, Caffeine, Dihydrocodeine Bitartrate. Using wintergreen oil topically in large amounts, with occlusive dressings, or for prolonged periods of time might increase the risk of additive salicylate toxicity when used with aspirin.

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

Wintergreen and Aspirin, Caffeine, Dihydrocodeine Bitartrate

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

Moderate

ASPIRIN

Using wintergreen oil topically in large amounts, with occlusive dressings, or for prolonged periods of time might increase the risk of additive salicylate toxicity when used with aspirin.
Wintergreen oil contains methyl salicylate. Topical analgesic gels, lotions, creams, ointments, liniments, and sprays can contain up to 55% methyl salicylate.
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 thing to keep in mind with Synalgos DC: it already contains aspirin, which is a salicylate. Wintergreen oil is loaded with methyl salicylate, a very close cousin of aspirin. So when you rub a lot of wintergreen on your skin, especially over big areas, under a wrap or bandage, or day after day, some of it gets absorbed and stacks on top of the aspirin you're already swallowing. That's an additive effect, more total salicylate in your body.

In real life that could mean things like ringing in the ears, nausea, stomach upset, or easier bruising and bleeding. This caution is based on how these chemicals behave rather than hard studies, and a small dab now and then is unlikely to be a problem. Still, please check with your pharmacist or doctor before pairing them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Gossel TA, Bricker JD. Principles of Clinical Toxicology. New York, NY:Raven Press, 1994.
  2. Covington TR, et al. Handbook of Nonprescription Drugs. 11th ed. Washington, DC: American Pharmaceutical Association, 1996.
  3. Joss JD, LeBlond RF. Potentiation of warfarin anticoagulation associated with topical methyl salicylate. Ann Pharmacother 2000;34:729-33. 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

Wintergreen Also Interacts With Other Medications

Wintergreen has 2 major, 34 moderate known drug interactions in our database — the Aspirin, Caffeine, Dihydrocodeine Bitartrate one above is one of them. If you take anything else, check it against the full list below.

Major 2 Moderate 34 No known interaction 2,794 (incl. Aspirin, Caffeine, Dihydrocodeine Bitartrate)
Taking anything else?

Check Another of Your Medications Against Wintergreen

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

Everything else you take

See Every Supplement That Interacts With Aspirin, Caffeine, Dihydrocodeine Bitartrate

This page covers Wintergreen only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aspirin, Caffeine, Dihydrocodeine Bitartrate 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.

Open the Aspirin, Caffeine, Dihydrocodeine Bitartrate interaction page

One more smart check

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

We hold 42 real supplement products containing Wintergreen, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Wintergreen. Your product may carry other ingredients that interact with Aspirin, Caffeine, Dihydrocodeine Bitartrate too, on top of Wintergreen — 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 Wintergreen and Aspirin, Caffeine, Dihydrocodeine Bitartrate 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 Wintergreen
Steady interest

#1,109 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Aspirin, Caffeine, Dihydrocodeine Bitartrate
Top 25%

#300 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 Wintergreen

What is Wintergreen?

  • Muscle and joint pain (topical)
  • Arthritis discomfort
  • Headaches
  • Sore throat and oral care
  • Flavoring agent

Wintergreen is a low-growing North American plant whose oil is rich in methyl salicylate, an aspirin-like compound used in topical pain rubs. While it may help ease minor muscle and joint pain when applied to the skin, the concentrated oil is highly toxic if swallowed and should never be taken by mouth. Talk with a pharmacist or doctor before using wintergreen products, especially around children.

Read the full Wintergreen monograph & all interactions
Keep checking

Other Drugs & Wintergreen

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

2Major
34Moderate
0Minor
2,793No known interaction
2 Major 34 Moderate 2,793 No interaction
Major

2 interactions

Moderate

34 interactions

No interaction 2,793 drugs checked — show the list

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

Showing the 60 most looked-up of 2,793 medications checked with no known interaction — see the full Wintergreen list.

See the full Wintergreen interactions page
See every supplement checked against Aspirin, Caffeine, Dihydrocodeine Bitartrate, 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
Wintergreen monograph › Uses, safety, and every drug interaction in one place Aspirin, Caffeine, Dihydrocodeine Bitartrate supplement interactions › Every supplement checked against Aspirin, Caffeine, Dihydrocodeine Bitartrate, 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 Wintergreen and Aspirin, Caffeine, Dihydrocodeine Bitartrate Together: Common Questions

Can you take Wintergreen with Aspirin, Caffeine, Dihydrocodeine Bitartrate?
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 Wintergreen and Aspirin, Caffeine, Dihydrocodeine Bitartrate 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 Aspirin, Caffeine, Dihydrocodeine Bitartrate and Wintergreen?

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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.