Drug & supplement interaction

Turpentine Oil + Fluorouracil

Fluorouracil brand names: Efudex, Tolak.

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

Turpentine Oil has a moderate interaction with Fluorouracil. 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 Fluorouracil

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

Moderate

TOPICAL DRUGS

Why this applies to Fluorouracil

Fluorouracil 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

When you're using a fluorouracil cream like Efudex or Tolak on your skin for precancerous spots or skin cancers, the worry here is about how much medicine soaks in. Turpentine oil is what we call a penetration enhancer, meaning it can irritate and open up the skin a bit. In theory, putting it on the same area could let more fluorouracil pass into your skin than intended.

If that happened, you might see stronger local reactions than usual, like more redness, burning, crusting, swelling, or soreness where you apply it. Honestly though, this concern comes only from lab and animal studies (it has never been clearly shown with fluorouracil in people), so the evidence is weak. Still, I wouldn't layer turpentine products onto a treated area. Check with your dermatologist or 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 Fluorouracil 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. Fluorouracil)
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 Fluorouracil

This page covers Turpentine Oil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fluorouracil page lists 26 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Alfalfa (moderate), Angelica Archangelica (moderate), Arrach (moderate), Bergamot (moderate) and Bishop's Weed (moderate).

By severity: 23 moderate · 3 minor.

From our pharmacist’s overview on the Fluorouracil page

“If you are using fluorouracil cream (Efudex, Tolak) on sun-damaged skin, your skin is already primed to react to sunlight, and that is where most of its supplement interactions sit. Of the 26 ingredients on file, 20 can make skin more sun-sensitive on their own, chlorophyll, chlorella, and bergamot oil among them, so pairing one with t…”

Reviewed by 2 · Jul 18, 2026

Open the Fluorouracil interaction page

How much people look this up

Where Turpentine Oil and Fluorouracil 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 Fluorouracil
Steady interest

#2,230 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 Fluorouracil Injection

What Is Fluorouracil Injection Used For?

Brand names: Efudex, Tolak

Fluorouracil Injection is used to treat four types of adenocarcinoma (a common form of cancer that begins in glandular cells): cancer of the colon and rectum, breast cancer, stomach (gastric) cancer, and pancreatic cancer.

It is nearly always given as part of a combination chemotherapy regimen alongside other cancer medicines, and the specific drugs paired with it depend on which cancer is being treated.

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

Can you take Turpentine Oil with Fluorouracil?
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 Fluorouracil 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 Fluorouracil 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.