Drug & supplement interaction

Turpentine Oil + Acetaminophen, Codeine, Methocarbamol

Acetaminophen, Codeine, Methocarbamol brand names: Acetaminophen, Codeine, Methocarbamol, Robaxacet 8.

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

Turpentine Oil has a minor interaction with Acetaminophen, Codeine, Methocarbamol. There is some concern that turpentine oil can inhibit CYP1A2 enzyme activity by up to 90% via induction of inflammation and subsequent downregulation of CYP activity.

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

Turpentine Oil and Acetaminophen, Codeine, Methocarbamol

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

Minor

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

Why this applies to Acetaminophen, Codeine, Methocarbamol

Acetaminophen, Codeine, Methocarbamol falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Turpentine Oil interacts with.

There is some concern that turpentine oil can inhibit CYP1A2 enzyme activity by up to 90% via induction of inflammation and subsequent downregulation of CYP activity. However, animal research suggests that turpentine oil does not affect the metabolism of phenacetin, a CYP1A2 substrate, despite inducing inflammation.
Some medications metabolized by CYP1A2 include clozapine (Clozaril), cyclobenzaprine (Flexeril), fluvoxamine (Luvox), haloperidol (Haldol), imipramine (Tofranil), mexiletine (Mexitil), olanzapine (Zyprexa), pentazocine (Talwin), propranolol (Inderal), tacrine (Cognex), theophylline, tizanidine (Zanaflex), zileuton (Zyflo), zolmitriptan (Zomig), and others.
Severity Minor Likelihood Unlikely Evidence D

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 honest take: the worry on file is that turpentine oil might block a liver enzyme called CYP1A2. With your Robaxacet combo, that enzyme mostly matters for the methocarbamol piece (the muscle relaxant). If it were truly blocked, methocarbamol could linger a bit longer, which might mean more drowsiness, dizziness, or a foggy feeling. The codeine and acetaminophen parts run through different pathways, so they aren't really the concern here.

That said, this is very weak, lab-only evidence, and animal studies didn't actually show a real effect. Tiny amounts rubbed on the skin almost certainly won't matter. Please never swallow turpentine oil. If you're using both, a quick check with your pharmacist is plenty.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Prasad VG, Vivek Ch, Anand Kumar P, Ravi Kumar P, Rao GS. Turpentine oil induced inflammation decreases absorption and increases distribution of phenacetin without altering its elimination process in rats. Eur J Drug Metab Pharmacokinet 2015;40(1):23-8. 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

Turpentine Oil Also Interacts With Other Medications

Turpentine Oil has 198 moderate, 177 minor known drug interactions in our database — the Acetaminophen, Codeine, Methocarbamol one above is one of them. If you take anything else, check it against the full list below.

Moderate 198 Minor 177 No known interaction 2,455 (incl. Acetaminophen, Codeine, Methocarbamol)
Taking anything else?

Check Another of Your Medications Against Turpentine Oil

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

Everything else you take

See Every Supplement That Interacts With Acetaminophen, Codeine, Methocarbamol

This page covers Turpentine Oil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Codeine, Methocarbamol page lists 243 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 Gamma-hydroxybutyrate (ghb) (major).

By severity: 10 major · 193 moderate · 40 minor.

Open the Acetaminophen, Codeine, Methocarbamol interaction page

How much people look this up

Where Turpentine Oil and Acetaminophen, Codeine, Methocarbamol 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 Turpentine Oil
Top half

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

29 days ago today
Medication Acetaminophen, Codeine, Methocarbamol
Top 5%

#103 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 Turpentine Oil

What is Turpentine Oil?

Turpentine Oil
  • Muscle and joint aches (topical)
  • Cough and congestion (chest rubs)
  • Minor skin conditions
  • Antiseptic
  • Toothache (traditional)

Turpentine oil is a strong-smelling pine resin product used mostly in tiny amounts in topical rubs for muscle aches and congestion. It can be dangerous and even deadly if swallowed, and reliable evidence for health benefits is very limited. Never drink turpentine oil, and only use diluted, purified products on the skin with care.

Read the full Turpentine Oil monograph & all interactions
Keep checking

Other Drugs & Turpentine Oil

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

0Major
198Moderate
177Minor
2,454No known interaction
198 Moderate 177 Minor 2,454 No interaction
Moderate

198 interactions

Showing 60 of 198 moderate interactions — see all 198 on the Turpentine Oil page.

Minor

177 interactions

Showing 60 of 177 minor interactions — see all 177 on the Turpentine Oil page.

No interaction 2,454 drugs checked — show the list

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

Showing the 60 most looked-up of 2,454 medications checked with no known interaction — see the full Turpentine Oil list.

See the full Turpentine Oil interactions page
See every supplement checked against Acetaminophen, Codeine, Methocarbamol, 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
Turpentine Oil monograph › Uses, safety, and every drug interaction in one place Acetaminophen, Codeine, Methocarbamol supplement interactions › Every supplement checked against Acetaminophen, Codeine, Methocarbamol, 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 Turpentine Oil and Acetaminophen, Codeine, Methocarbamol Together: Common Questions

Can you take Turpentine Oil with Acetaminophen, Codeine, Methocarbamol?
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 Turpentine Oil and Acetaminophen, Codeine, Methocarbamol 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 Acetaminophen, Codeine, Methocarbamol and Turpentine Oil?

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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.