Drug & supplement interaction

Turpentine Oil + Diphenhydramine

Diphenhydramine brand names: Benadryl, Dormin, Allerdryl, Valdrene, Sleep-Ettes D, and others.

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

Turpentine Oil has a moderate interaction with Diphenhydramine. 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?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Turpentine Oil and Diphenhydramine

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

Moderate

TOPICAL DRUGS

Why this applies to Diphenhydramine

Diphenhydramine 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 gist: turpentine oil works as a skin penetration helper. In a couple of lab and animal studies, it pushed more of certain drugs through the skin. So if you ever used a topical diphenhydramine product (like an anti-itch cream) on the same patch of skin, the theory is that more of it could get absorbed than usual.

If that happened, you might notice stronger antihistamine effects, things like drowsiness, dry mouth, or a foggy head. That said, this is theoretical and based only on lab and animal work, not human studies. It also wouldn't apply to diphenhydramine you swallow as a pill. If you use both on your skin, just space them apart and check with your pharmacist 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 Diphenhydramine 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. Diphenhydramine)
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.

From our Q&A

Questions About Turpentine Oil or Diphenhydramine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Turpentine Oil or Diphenhydramine, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Diphenhydramine

This page covers Turpentine Oil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Diphenhydramine page lists 147 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), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Henbane (major).

By severity: 9 major · 119 moderate · 19 minor.

From our pharmacist’s overview on the Diphenhydramine page

“Diphenhydramine (Benadryl, Simply Sleep) is sedating by design, and most of the 147 supplements and herbal ingredients on this list lean into that. Seventy-eight are sedating substances themselves, alcohol and kava the standouts, and stacking them can slow breathing and reflexes well beyond ordinary drowsiness.”

Reviewed by 2 · Jul 18, 2026

Open the Diphenhydramine interaction page

How much people look this up

Where Turpentine Oil and Diphenhydramine 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
Steady interest

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

29 days ago today
Medication Diphenhydramine
Top 25%

#321 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 Diphenhydramine

What Is Diphenhydramine Used For?

Brand names: Benadryl, Dormin, Allerdryl, Valdrene, Sleep-Ettes D, Simply Sleep, Sominex, Diphenhydramine, Compoz, Sleep Aid, Benadryl cream, Benadryl spray, Dermamycin cream, Ziradryl, Nytol

Diphenhydramine temporarily relieves symptoms of hay fever, other upper respiratory allergies, and the common cold — including runny nose, sneezing, itchy or watery eyes, and itching of the nose or throat.

After Bite Xtra gel is formulated for topical use and is approved to temporarily relieve pain and itching from minor burns, minor cuts and scrapes, insect bites, minor skin irritations, and rashes from poison ivy, poison oak, and poison sumac.

See full Diphenhydramine 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 Diphenhydramine, 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 Diphenhydramine supplement interactions › Every supplement checked against Diphenhydramine, ranked by severity Diphenhydramine 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 Diphenhydramine Together: Common Questions

Can you take Turpentine Oil with Diphenhydramine?
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 Diphenhydramine 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 Diphenhydramine and Turpentine Oil?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.