Drug & supplement interaction

Turpentine Oil + Doxepin

Doxepin brand names: Sinequan, Doxepin, Zonalon.

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

Turpentine Oil has a moderate interaction with Doxepin. Some in vitro research shows that alpha-pinene, the major constituent of turpentine oil, does not increase the absorption of chlorpromazine or haloperidol when applied topically.

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

Turpentine Oil and Doxepin

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

Moderate

TOPICAL DRUGS

Why this applies to Doxepin

Doxepin falls under TOPICAL DRUGS — the group Turpentine Oil interacts with.

Some in vitro research shows that alpha-pinene, the major constituent of turpentine oil, does not increase the absorption of chlorpromazine or haloperidol when applied topically. However, animal research shows that turpentine oil increases the absorption of ibuprofen when applied topically. Theoretically, applying turpentine oil to the skin along with other medications might increase the effects and side effects of these medications.
Severity Moderate 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 situation with Doxepin, which you may be using as the topical cream (Zonalon) for itchy skin, or as Silenor for sleep. The concern here is about skin absorption. Turpentine oil acts as a mild skin irritant, and in animal studies it helped another medicine (ibuprofen) soak through the skin faster. So in theory, rubbing turpentine oil on the same patch of skin as doxepin cream might push more of the doxepin into your body than intended.

If that happened, you could feel more of doxepin's usual effects, like drowsiness, dry mouth, dizziness, or feeling groggy. I want to be honest though: this is theoretical and based only on lab and animal work, not real patients. Still, it's smart to keep these two products off the same area of skin and to run it by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Jiang Q, Wu Y, Zhang H, et al. Development of essential oils as skin permeation enhancers: penetration enhancement effect and mechanism of action. Pharmaceutical Biol. 2017;55(1):1592-1600. PubMed
  2. Almirall M, Montana J, Excribano E, Obach R, Berrozpe JD. Effect of d-limonene, alpha-pinene, and cineole on in vitro transdermal human skin penetration of chlorpromazine and haloperidol. Arzneimittelforschung. 1996 Jul;46(7):676-80.

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 197 moderate, 178 minor known drug interactions in our database — the Doxepin one above is one of them. If you take anything else, check it against the full list below.

Moderate 197 Minor 178 No known interaction 2,455 (incl. Doxepin)
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 Doxepin

This page covers Turpentine Oil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Doxepin page lists 186 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), American Hellebore (major), Arsenic (major) and Beer (major).

By severity: 15 major · 145 moderate · 26 minor.

From our pharmacist’s overview on the Doxepin page

“Doxepin is a sedating tricyclic prescribed for depression, anxiety, and often sleep itself, and the people taking it tend to shop the same shelf where the trouble sits. Of the 186 supplements on file, 78 deepen its drowsiness, with alcohol (beer and wine carry major, well-documented ratings) and kava the clearest examples, and I would…”

Reviewed by 2 · Jul 18, 2026

Open the Doxepin interaction page

How much people look this up

Where Turpentine Oil and Doxepin 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

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

29 days ago today
Medication Doxepin
Steady interest

#1,473 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
Medication

About Doxepin (Insomnia)

What Is Doxepin (Insomnia) Used For?

Brand names: Sinequan, Doxepin, Zonalon

This product is marketed to temporarily relieve occasional trouble sleeping when it's brought on by anxiety, restlessness, stress, or sensitivity to caffeine.

It is a homeopathic remedy — meaning its claims are based on traditional homeopathic practice, not accepted medical evidence, and it has not been evaluated by the FDA for effectiveness.

See full Doxepin (Insomnia) drug information
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
197Moderate
178Minor
2,454No known interaction
197 Moderate 178 Minor 2,454 No interaction
Moderate

197 interactions

Showing 60 of 197 moderate interactions — see all 197 on the Turpentine Oil page.

Minor

178 interactions

Showing 60 of 178 minor interactions — see all 178 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 Doxepin, 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 Doxepin supplement interactions › Every supplement checked against Doxepin, ranked by severity Doxepin (Insomnia) drug information › The full plain-English guide to this medication 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 Doxepin Together: Common Questions

Can you take Turpentine Oil with Doxepin?
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 Turpentine Oil and Doxepin 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 Doxepin 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.