Drug & supplement interaction

Turpentine Oil + Estradiol

Estradiol brand names: Estrace, Gynodiol, Vagifem, Estring, Vivelle, and others.

Moderate Interaction
The bottom line Moderate

Estradiol falls into 2 drug categories that Turpentine Oil can interact with; the most serious is rated moderate. 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
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Turpentine Oil and Estradiol

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Turpentine Oil interacts with whole categories of medication. Estradiol falls into 2 of those categories, so it can interact with Turpentine Oil in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

TOPICAL DRUGS

1 of 2

Why this applies to Estradiol

Estradiol 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 simple version: turpentine oil is a skin penetration helper. In animal studies it pushed more ibuprofen through the skin when the two touched the same spot. So the theory is that if you rub turpentine oil over an area where you're also using a topical estradiol product, more estrogen could soak in than intended.

If that happened, you might notice estrogen-type effects like breast tenderness, bloating, headaches, nausea, or spotting. To be fair, this is mostly lab and animal data (weak evidence), and it really only matters if both products go on the same patch of skin. Vaginal estradiol forms aren't a likely overlap. To play it safe, don't apply turpentine rubs near your estradiol site, and check with your pharmacist or doctor first.

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.
Minor

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

2 of 2

Estradiol also falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES.

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 picture for estradiol. Your body partly clears estrogen using a liver enzyme called CYP1A2. In theory, turpentine oil might slow that enzyme down, which could let a little more estradiol linger in your system. If that happened, you might notice more estrogen-type effects like breast tenderness, bloating, headaches, or nausea. Estradiol is not a prodrug, so it doesn't need this enzyme to start working.

That said, the evidence here is very thin. It comes only from lab and animal studies, and one animal test actually showed no real change in how a CYP1A2 drug was handled. With the dabs of turpentine used in skin rubs, a meaningful interaction is unlikely. Still, mention it to your pharmacist or doctor to be safe.

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

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 Estradiol

This page covers Turpentine Oil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Estradiol page lists 213 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 172 moderate · 38 minor.

From our pharmacist’s overview on the Estradiol page

“Estradiol (Estrace, Vivelle, Vagifem, and other brands) is estrogen therapy, and its interaction list deserves careful reading, especially the three entries rated major. Grapefruit can push estradiol levels higher, St.”

Reviewed by 2 · Jul 18, 2026

Open the Estradiol interaction page

How much people look this up

Where Turpentine Oil and Estradiol 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

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

29 days ago today
Medication Estradiol
Top 25%

#523 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
197Moderate
178Minor
2,454No known 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
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

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Pharmacist Counseling Corner

Taking Turpentine Oil and Estradiol Together: Common Questions

Can you take Turpentine Oil with Estradiol?
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.
Why are there 2 interactions listed for Turpentine Oil and Estradiol?
Estradiol belongs to more than one drug category, and Turpentine Oil 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 Turpentine Oil and Estradiol 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

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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.