Herb & supplement monograph

Tung Seed Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by ·Updated July 2026
What is this page for?

First and foremost: how Tung Seed interacts with medications. The heart of this page is the interaction list — every drug Tung Seed is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Tung Seed is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Interaction report

Drugs that interact with Tung Seed

0 medications have a known interaction with Tung Seed, graded by severity. Select any drug for the full evidence-based detail.

We don’t currently list any known drug interactions for Tung Seed. This doesn’t guarantee none exist — always confirm with your pharmacist before combining supplements with your medications.

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction 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.
  • Possible. 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
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each drug listed above links to the full report for that exact Tung Seed combination — clinical detail, likelihood, evidence level, and citations.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
Monograph

Tung Seed: Uses, Safety & Side Effects

Medically reviewed by · Reviewed July 2026 ·
The bottom line

Tung seed comes from the tung tree (Vernicia fordii), and its main product is tung oil, which is used mostly as an industrial wood finish, not as a food or medicine. The raw seeds and oil are toxic if swallowed and there is no reliable evidence supporting any health benefit. We do not recommend taking tung seed as a supplement.

Scientific name
Vernicia fordii
Family
Euphorbiaceae
Part used
Seeds and the oil pressed from them (tung oil)
Common forms
Tung oil (industrial), rarely available as a dietary supplement
People commonly use it for
  • Wood finishing and varnish (industrial)
  • Traditional folk skin applications
  • Traditional laxative use (historical)
  • Traditional topical remedies

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance
OverallBest avoided

Tung seeds and oil are poisonous if eaten and are not safe as a supplement.

PregnancyLikely Unsafe

When used orally; avoid using.

Read the full pregnancy detail
BreastfeedingLikely Unsafe

When used orally; avoid using.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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Overview

Tung seed comes from the tung tree (Vernicia fordii), a flowering tree in the spurge family that is native to China and grown in warm regions, including parts of the southern United States. The tree is best known for the oil pressed from its seeds, called tung oil.

Tung oil is used mostly in industry. It is a popular wood finish and is found in varnishes, paints, and waterproof coatings because it dries into a hard, water-resistant surface. It is not a food oil and is not commonly sold as a dietary supplement.

While some traditional practices have used parts of the tung tree topically or as a folk remedy, the seeds and oil are well known to be poisonous when swallowed. For this reason, tung seed is not used as a normal health supplement today.

How it works

Tung oil is rich in a special fatty acid called alpha-eleostearic acid, which gives the oil its quick-drying, hardening quality that makes it useful as a wood finish.

The seeds also contain toxic substances, including compounds that can irritate the stomach and gut. Some early laboratory studies have looked at certain compounds from the plant for possible biological effects, but this is very preliminary research done in test tubes or animals, not in people. None of it shows that tung seed is safe or useful as a medicine.

Effectiveness

Does Tung Seed work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by .

Evidence overview · 4 uses evaluated
4 Insufficient evidence
How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.
2Likely EffectiveGood evidence, though not yet conclusive.
3Possibly EffectiveSome evidence suggests a benefit.
4Possibly IneffectiveSome evidence it may not help.
5Likely IneffectiveFairly strong evidence it doesn’t help.
6IneffectiveStrong evidence it doesn’t work.
7Insufficient Reliable Evidence to RateToo little research to say either way.

For Tung Seed, current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.

Also studied for 4 conditions — evidence insufficient to rate
Insufficient Reliable Evidence To Rate Alopecia areata
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using topical candlenut to stimulate hair growth, there is insufficient reliable information about the clinical effects of candlenut for this purpose.

Insufficient Reliable Evidence To Rate Asthma
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral candlenut for asthma, there is insufficient reliable information about the clinical effects of candlenut for this purpose.

Insufficient Reliable Evidence To Rate Constipation
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using topical candlenut for constipation, there is insufficient reliable information about the clinical effects of candlenut for this purpose.

Insufficient Reliable Evidence To Rate Obesity
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral candlenut for weight loss, there is insufficient reliable information about the clinical effects of candlenut for this purpose and consumption may be unsafe.

Source & disclaimer. Effectiveness ratings and evidence summaries are provided by Natural Medicines (Therapeutic Research Center) and shown as licensed. Where Natural Medicines hasn’t rated a use, HelloPharmacist’s pharmacists may add their own reviewed rating and evidence (each such entry is labeled). This is educational information, not medical advice — talk with your pharmacist or doctor before starting, stopping, or changing a supplement.

Safety & precautions

Tung seeds and tung oil are toxic and should not be eaten. Even swallowing a small number of seeds has been reported to cause poisoning. Because of this, tung seed should not be used as a dietary supplement.

The seeds can be mistaken for edible nuts, which has led to accidental poisonings. Keep tung seeds, tung oil products, and any wood finishes containing them away from children and pets.

Pregnancy and breastfeeding: Tung seed should be avoided entirely during pregnancy and breastfeeding because it is toxic. There is no safe known dose.

If you have any tung-based product, treat it as an industrial chemical, not a health product. Always talk with a pharmacist or doctor before considering any unfamiliar plant remedy.

Side effects

Swallowing tung seeds or tung oil can cause nausea, vomiting, stomach cramps, and severe diarrhea. More serious poisoning has been linked to dizziness, weakness, breathing problems, and changes in heart rhythm.

Skin or eye contact with the raw oil may cause irritation in some people. If someone swallows tung seed or oil, treat it as a poisoning emergency and contact a poison control center or seek medical care right away.

Tung Seed: Reported Adverse Effects

Documented safety reports on Tung Seed from the evidence-graded Natural Medicines (TRC Healthcare) database, shown word-for-word from the licensed record.

Reports by condition
Dermatitis Dermatologic

Topically, candlenut can cause acute dermatitis.

  1. Duke JA. CRC handbook of medicinal herbs. 1st ed. Boca Raton, FL: CRC Press, LLC, 1985.
Diarrhea Gastrointestinal

Orally, candlenut can cause severe abdominal pain, violent vomiting, and diarrhea.

  1. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  2. Duke JA. CRC handbook of medicinal herbs. 1st ed. Boca Raton, FL: CRC Press, LLC, 1985.
  3. O'Brien DR, Szymczuk V, Albaro CA. Weight loss supplement causing acute heart block in a child. Cardiol Young 2020;30(1):131-133.
  4. Lawani O, Winter M. Heart Block Initiated by Candlenut Ingestion. Case Rep Cardiol 2022;2022:3679968.
Diarrhea Cardiovascular

A 16-year-old patient presented with acute onset abdominal pain, chest pain, and profuse and persistent vomiting following ingestion of both a tea made from boiling a whole candlenut and the boiled candlenut itself. The patient was also found to have first-degree heart block that later progressed to Mobitz type I second degree heart block with occasional 2:1 block, requiring ICU admission and monitoring. Symptoms abated by the third day and a follow-up EKG at 1 week was normal. After ingesting a whole candlenut, a 21-year-old patient presented with nausea, vomiting, generalized malaise, decreased heart rate, and numbness and tingling in the extremities. The patient was found to have first-degree heart block that progressed to third-degree block, requiring ICU admission. Treatment with digoxin immune Fab, sodium bicarbonate, dopamine, and 20% fat emulsion was initiated. The patient's EKG normalized approximately 7 days after ingesting the candlenut. A 44-year-old patient in Brazil developed acute abdominal pain, diarrhea, chest discomfort, and shortness of breath, and subsequently presented to the emergency department with altered mental status and unresponsiveness after taking a candlenut weight loss supplement for 2 days. The patient was found to have second-degree heart block and was admitted to the hospital for monitoring, IV fluids, and antiemetics. After two days, the patient's EKG returned to normal and they were discharged without sequelae.

  1. O'Brien DR, Szymczuk V, Albaro CA. Weight loss supplement causing acute heart block in a child. Cardiol Young 2020;30(1):131-133.
  2. Lawani O, Winter M. Heart Block Initiated by Candlenut Ingestion. Case Rep Cardiol 2022;2022:3679968.
  3. Koons AL, Laubach LT, Katz KD, Beauchamp GA. Mobitz Type II Atrioventricular Heart Block After Candlenut Ingestion. J Am Osteopath Assoc. 2020;120(12):839-843.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

Adverse-effects data: Natural Medicines, Therapeutic Research Center

Dosing

There is no established or safe dose of tung seed for use in people. Because the seeds and oil are toxic, no medical dosing exists, and we do not recommend taking it in any amount.

If you see a product that claims to contain tung seed for health purposes, do not use it without first checking with a pharmacist or doctor. In general, tung oil should be treated as an industrial product only.

Pregnancy & Breastfeeding

Tung Seed & Pregnancy

Likely Unsafe

When used orally; avoid using.

  1. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.

Tung Seed & Breastfeeding

Likely Unsafe

When used orally; avoid using.

  1. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

© 2026 Therapeutic Research Center

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

The 5 references that drive our Tung Seed monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  2. Duke JA. CRC handbook of medicinal herbs. 1st ed. Boca Raton, FL: CRC Press, LLC, 1985.
  3. O'Brien DR, Szymczuk V, Albaro CA. Weight loss supplement causing acute heart block in a child. Cardiol Young 2020;30(1):131-133. PubMed
  4. Lawani O, Winter M. Heart Block Initiated by Candlenut Ingestion. Case Rep Cardiol 2022;2022:3679968. PubMed
  5. Koons AL, Laubach LT, Katz KD, Beauchamp GA. Mobitz Type II Atrioventricular Heart Block After Candlenut Ingestion. J Am Osteopath Assoc. 2020;120(12):839-843. PubMed
Keep reading

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.

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

Pharmacist Counseling Corner

Tung Seed: Common Questions

What is Tung Seed used for, and does it work?
People use Tung Seed for a range of reasons, but according to the Natural Medicines database the current clinical evidence is insufficient to confirm it works for the specific conditions it has been studied for. See the graded list on this page, and talk to your pharmacist or doctor before relying on it for any condition.
Does Tung Seed interact with prescription medications?
We do not currently list any known drug interactions for Tung Seed. This does not guarantee that none exist, so always confirm with your pharmacist before combining it with your medications.
How are Tung Seed interactions rated?
Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.
Is it safe to take Tung Seed with my medications?
It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.
Where does this Tung Seed interaction information come from?
Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.
Is Tung Seed safe to eat or take as a supplement?
No. Tung Seeds and tung oil are poisonous if swallowed and can cause serious stomach and other symptoms. They should not be eaten or taken as a supplement.
What is tung oil actually used for?
Tung oil is used mostly as a wood finish and in varnishes, paints, and protective coatings. It is an industrial product, not a food or medicine.
What should I do if someone swallows Tung Seeds?
Treat it as a poisoning emergency. Contact your local poison control center or seek medical care right away, especially for children.
Can I use Tung Seed during pregnancy or breastfeeding?
No. Tung Seed is toxic and should be completely avoided during pregnancy and breastfeeding.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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