Drug & supplement interaction

Tea Tree Oil + Cefdinir

Cefdinir brand name: Omnicef.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Tea Tree Oil and Cefdinir in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Tea Tree Oil and Cefdinir

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Cefdinir and Tea Tree Oil in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for Tea Tree Oil at all — not against Cefdinir, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Tea Tree Oil safety at a glance

Tea Tree Oil overall Use caution Generally safe when used diluted on the skin, but it is toxic if swallowed.
Pregnancy Possibly Safe When used topically and appropriately. Read the full pregnancy detail
Breastfeeding Possibly Safe When used topically and appropriately. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Cefdinir and Tea Tree Oil? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Tea Tree Oil and Cefdinir May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. 2 of them are worth acting on rather than waiting out — marked below.

  • A higher chance of infection Worth acting on reported in 6.3% of FDA reports for Cefdinir Additional detail

    Tea Tree Oil

    “There is some concern that topical use of tea tree oil in the middle ear for treatment of ear infections might cause ototoxicity. There is preliminary evidence from animal research that preparations of pure tea tree oil can cause ototoxicity and impaired hearing. However, so far there are no reports of ototoxicity in humans.”

    Tea Tree Oil · Natural Medicines adverse-effect record, reported in drug-induced hearing loss.

    1 source cited
    1. 7025. Zhang SY, Robertson D. A study of tea tree oil ototoxicity. Audiol Neurootol 2000;5:64-8. PubMed

    Cefdinir

    Listed in the ADVERSE REACTIONS section of the FDA label for Cefdinir, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

  • An allergic reaction Worth acting on Additional detail

    Tea Tree Oil

    “Orally, tea tree oil can cause significant toxicity and should not be used. Topically, tea tree oil is generally well tolerated.

    Most Common Adverse Effects:

    Topically: Allergic reactions, burning, dryness, irritation, pruritus, redness, and stinging.”

    Tea Tree Oil · Natural Medicines adverse-effect record, reported in pruritus.

    Cefdinir

    Listed in the ADVERSE REACTIONS section of the FDA label for Cefdinir. Read the label on DailyMed ›

  • Drowsiness Additional detail

    Tea Tree Oil

    “Orally, tea tree oil can cause or worsen systemic contact dermatitis. Topically, tea tree oil is usually well tolerated. However, it can cause allergic contact eczema and allergic contact dermatitis in some children and adults. Corticosteroids may be needed in some cases.

    In young children, ingestion of 10 mL or less of tea tree oil can cause significant ataxia, drowsiness, disorientation, and coma.”

    Tea Tree Oil · Natural Medicines adverse-effect record, reported in dermatitis.

    6 sources cited
    1. 4028. Carson CF, Riley TV, Cookson BD. Efficacy and safety of tea tree oil as a topical antimicrobial agent. J Hosp Infect 1998;40:175-8. PubMed
    2. 19168. De Groot A. C. and Weyland J. W. Systemic contact dermatitis from tea tree oil. Contact Dermatitis 1992;27(4):279-280. PubMed
    3. 658. De Groot AC. Airborn allergic contact dermatitis from tea tree oil. Contact Dermatitis 1996;35:304-5.
    4. 4027. Rubel DM, Freeman S, Southwell IA. Tea tree oil allergy: what is the offending agent? Report of three cases of tea tree oil allergy and review of the literature. Australas J Dermatol 1998;39:244-7. PubMed
    5. 4029. Bhushan M, Beck MH. Allergic contact dermatitis from tea tree oil in a wart paint. Contact Dermatitis 1997;36:117-8. PubMed
    6. 10015. Knight TE, Hausen BM. Melaleuca oil (tea tree oil) dermatitis. J Am Acad Dermatol 1994;30:423-7.. PubMed

    Cefdinir

    Listed in the ADVERSE REACTIONS section of the FDA label for Cefdinir. Read the label on DailyMed ›

  • Itching Additional detail

    Tea Tree Oil

    “Ingestion of as little as 2.5 mL of tea tree oil can cause petechial body rash. It can take up to a week for symptoms to resolve.

    Topically, tea tree oil is usually well tolerated. However, it can cause local irritation and inflammation in some patients. Treatment with topical corticosteroids may be needed in some cases. Severe allergic contact dermatitis has also been reported.”

    Tea Tree Oil · Natural Medicines adverse-effect record, reported in acne.

    6 sources cited
    1. 10011. Elliott C. Tea tree oil poisoning. Med J Aust 1993;159:830-1. PubMed
    2. 10033. Satchell AC, Saurajen A, Bell C, Barnetson RS. Treatment of interdigital tinea pedis with 25% and 50% tea tree oil solution: a randomized, placebo-controlled, blinded study. Australas J Dermatol 2002;43:175-8.. PubMed
    3. 13713. Martin KW, Ernst E. Herbal medicines for treatment of fungal infections: a systematic review of controlled clinical trials. Mycoses 2004;47:87-92. PubMed
    4. 19176. Enshaieh S, Jooya A, Siadat AH, and Iraji F. The efficacy of 5% topical tea tree oil gel in mild to moderate acne vulgaris: a randomized, double-blind placebo-controlled study. Indian J Dermatol Venereol Leprol 2007;73(1):22-25. PubMed
    5. 91442. Christoffers WA, Blömeke B, Coenraads PJ, Schuttelaar ML. Co-sensitization to ascaridole and tea tree oil. Contact Dermatitis. 2013 Sep;69(3):187-9. PubMed
    6. 91443. Corazza M, Borghi A, Gallo R, Schena D, Pigatto P, Lauriola MM, Guarneri F, Stingeni L, Vincenzi C, Foti C, Virgili A. Topical botanically derived products: use, skin reactions, and usefulness of patch tests. A multicentre Italian study. Contact Dermatiti

    Cefdinir

    Listed in the ADVERSE REACTIONS section of the FDA label for Cefdinir. Read the label on DailyMed ›

  • A skin rash Additional detail

    Tea Tree Oil

    Recorded for Tea Tree Oil in the same Natural Medicines adverse-effect record shown under Itching above.

    Cefdinir

    Listed in the ADVERSE REACTIONS section of the FDA label for Cefdinir. Read the label on DailyMed ›

Reported for Tea Tree Oil but not commonly for Cefdinir: hearing loss, confusion, dry skin and unsteadiness.

Effects for Cefdinir come from the ADVERSE REACTIONS section of its FDA label; effects for Tea Tree Oil come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 7,629 voluntary FDA FAERS reports for Cefdinir that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Tea Tree Oil in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Safe

When used topically and appropriately.

Pregnancy And Lactation Likely Unsafe

When used orally. Ingestion of tea tree oil can be toxic.

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

Overlapping uses

What Cefdinir Is Prescribed For, and What Tea Tree Oil Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Cefdinir is a prescription medicine with approved uses on its FDA label. Tea Tree Oil is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Cefdinir is prescribed for: Cefdinir treats mild to moderate bacterial infections in adults, adolescents, and children caused by susceptible bacteria. It is used for community-acquired pneumonia, acute exacerbations of chronic bronchitis, acute maxillary sinusitis (sinus infection), pharyngitis/tonsillitis (strep throat), and uncomplicated skin and skin structure infections. In pediatric patients (ages 6 months through 12 years), cefdinir is also used to treat acute bacterial otitis media (middle ear infection). It should only be used for infections that are proven or strongly suspected to be caused by bacteria — not for viral illnesses like the common cold.

Tea Tree Oil has been studied for:

  • Otitis media studied, not established Tea Tree Oil has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Tea Tree Oil for otitis media

    Although there is interest in using tea tree oil in the ear for otitis media, there is insufficient reliable information about the clinical effects of tea tree oil for this condition.

  • Pharyngitis studied, not established Tea Tree Oil has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Tea Tree Oil for pharyngitis

    Although there is interest in gargling with tea tree oil for pharyngitis, there is insufficient reliable information about the clinical effects of tea tree oil for this purpose.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Cefdinir on your own; if you are taking Tea Tree Oil for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Tea Tree Oil or Cefdinir

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Tea Tree Oil or Cefdinir, 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 Cefdinir

This page covers Tea Tree Oil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Cefdinir page lists 60 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Siberian Cocklebur (major), African Wild Potato (moderate) and Aristolochia (moderate).

By severity: 3 major · 46 moderate · 11 minor.

From our pharmacist’s overview on the Cefdinir page

“Cefdinir (Omnicef) is a short-course antibiotic for ear, sinus, throat, and skin infections, and three of its 60 supplement interactions on file are rated major and deserve genuine care. Two herbs, Siberian cocklebur and asarabacca, can damage the kidneys, an added strain nobody needs while fighting an infection.”

Reviewed by 2 · Jul 18, 2026

Open the Cefdinir interaction page

How much people look this up

Where Tea Tree Oil and Cefdinir 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 Tea Tree Oil
Steady interest

#1,089 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Cefdinir
Steady interest

#2,025 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Tea Tree Oil reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Tea Tree Oil and Cefdinir records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Tea Tree Oil

What is Tea Tree Oil?

Tea Tree Oil
  • Acne
  • Fungal skin infections (athlete's foot, nail fungus)
  • Dandruff
  • Minor wounds and insect bites
  • Lice

Tea tree oil is an essential oil used on the skin for acne, fungal infections, and other skin problems, with some supportive but limited evidence. It is for topical use only and should never be swallowed, as it can be toxic. Always dilute it, do a patch test first, and check with your pharmacist or doctor before using.

Melaleuca alternifolia · Myrtaceae · Leaves and twigs (steam-distilled into essential oil) · Essential oil, creams, gels, ointments, soaps, shampoos, mouthwash

An interaction check asks whether these two react with each other — it does not ask whether Tea Tree Oil is a good idea for someone in your situation. Here is what our Tea Tree Oil record says about it on its own.

Tea Tree Oil: dosing

There is no official standardized dose for tea tree oil. Many skin products contain it at low concentrations, often diluted to a small percentage of the total product.The safest approach is to follow the directions on the product label and not apply more or more often than directed. If you are using pure essential oil, dilute it with a carrier oil before use. Never take it by mouth.

From our Tea Tree Oil monograph — the full record covers uses, side effects and every documented interaction.

Read the full Tea Tree Oil monograph & all interactions
Medication

About Cefdinir

What Is Cefdinir Used For?

Brand name: Omnicef

Cefdinir treats mild to moderate bacterial infections in adults, adolescents, and children caused by susceptible bacteria. It is used for community-acquired pneumonia, acute exacerbations of chronic bronchitis, acute maxillary sinusitis (sinus infection), pharyngitis/tonsillitis (strep throat), and uncomplicated skin and skin structure infections.

In pediatric patients (ages 6 months through 12 years), cefdinir is also used to treat acute bacterial otitis media (middle ear infection). It should only be used for infections that are proven or strongly suspected to be caused by bacteria — not for viral illnesses like the common cold.

Most-Reported Side Effects for Cefdinir

From FAERS, the FDA’s public side-effect reporting system (7,629 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Diarrhea 530 reports
Chronic kidney disease 485 reports
Pneumonia 482 reports
Fatigue 462 reports
Nausea 400 reports
See full Cefdinir drug information
Keep checking

Other Drugs & Tea Tree Oil

Browse every other medication we’ve checked against Tea Tree Oil — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

We also checked Tea Tree Oil against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Tea Tree Oil list.

See the full Tea Tree Oil interactions page
See every supplement checked against Cefdinir, ranked by severity
Evidence & sources

Tea Tree Oil References

The 31 references that drive our Tea Tree Oil 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. Robbers JE, Tyler VE. Tyler's Herbs of Choice: The Therapeutic Use of Phytomedicinals. New York, NY: The Haworth Herbal Press, 1999.
  2. Foster S, Tyler VE. Tyler's Honest Herbal, 4th ed., Binghamton, NY: Haworth Herbal Press, 1999. DOI
  3. De Groot AC. Airborn allergic contact dermatitis from tea tree oil. Contact Dermatitis 1996;35:304-5.
  4. Rubel DM, Freeman S, Southwell IA. Tea tree oil allergy: what is the offending agent? Report of three cases of tea tree oil allergy and review of the literature. Australas J Dermatol 1998;39:244-7. PubMed
  5. Carson CF, Riley TV, Cookson BD. Efficacy and safety of tea tree oil as a topical antimicrobial agent. J Hosp Infect 1998;40:175-8. PubMed
  6. Bhushan M, Beck MH. Allergic contact dermatitis from tea tree oil in a wart paint. Contact Dermatitis 1997;36:117-8. PubMed
  7. Del Beccaro MA. Melaleuca oil poisoning in a 17-month-old. Vet Hum Toxicol 1995;37:557-8.
  8. Jandourek A, Vaishampayan JK, Vazquez JA. Efficacy of melaleuca oral solution for the treatment of fluconazole refractory oral candidiasis in AIDS patients. AIDS 1998;12:1033-7. DOI
  9. Zhang SY, Robertson D. A study of tea tree oil ototoxicity. Audiol Neurootol 2000;5:64-8. PubMed
  10. Bassett IB, Pannowitz DL, Barnetson RS. A comparative study of tea-tree oil versus benzoylperoxide in the treatment of acne. Med J Aust 1990;153:455-8. PubMed
  11. Jacobs MR, Hornfeldt CS. Melaleuca oil poisoning. J Toxicol Clin Toxicol 1994;32:461-4.. PubMed
  12. Elliott C. Tea tree oil poisoning. Med J Aust 1993;159:830-1. PubMed
  13. Knight TE, Hausen BM. Melaleuca oil (tea tree oil) dermatitis. J Am Acad Dermatol 1994;30:423-7.. PubMed
  14. Bruynzeel DP. Contact dermatitis due to tea tree oil. Trop Med Int Health 1999;4:630.
  15. Greig JE, Thoo SL, Carson CF, Riley TV. Allergic contact dermatitis following use of a tea tree oil hand-wash not due to tea tree oil. Contact Dermatitis 1999;41:354-5. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Tea Tree Oil and Cefdinir Together: Common Questions

Is it safe to take Tea Tree Oil with Cefdinir?
We do not list a known interaction between Tea Tree Oil and Cefdinir. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Tea Tree Oil and Cefdinir have any of the same side effects?
Yes — our sources link each of them separately to 5 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Are Tea Tree Oil and Cefdinir used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Tea Tree Oil in each. That is a conversation for your prescriber, especially if Cefdinir is being adjusted to a target.
Does Cefdinir interact with any supplements?
Yes. Cefdinir has documented interactions with 60 supplements in our database — Tea Tree Oil is not one of them. The Cefdinir interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Tea Tree Oil monograph Uses, safety profile, and every drug interaction in one place Cefdinir drug information The full plain-English guide to this medication Cefdinir supplement interactions Every supplement checked against Cefdinir, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 31 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Cefdinir and Tea Tree 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.