Drug & supplement interaction

Eucalyptus + Levothyroxine

Levothyroxine brand names: Euthyrox, Levothroid, Unithroid, Synthroid, Levoxyl, and others.

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 Eucalyptus and Levothyroxine 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 label for Levothyroxine states a food rule worth keeping to, and 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

Eucalyptus and Levothyroxine

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 Levothyroxine and Eucalyptus 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.

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.

Eucalyptus safety at a glance

Eucalyptus overall Use caution Generally safe in small amounts for inhalation or diluted topical use, but the undiluted oil can be poisonous if swallowed.
Pregnancy Likely Safe When used orally in amounts commonly found in foods. There is insufficient reliable information available about the safety of medicinal amounts of eucalyptus oi... Read the full pregnancy detail
Breastfeeding Likely Safe When used orally in amounts commonly found in foods. There is insufficient reliable information available about the safety of medicinal amounts of eucalyptus oi... 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 Levothyroxine and Eucalyptus? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Levothyroxine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Levothyroxine is filed under 3 classifications — including thyroid hormone, oral drugs. Eucalyptus has documented interactions with 7 drug classes — the most serious being amphetamines (moderate), antidiabetes drugs (moderate) and cytochrome p450 1a2 (cyp1a2) substrates (moderate) — and none of Levothyroxine’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Eucalyptus Does Interact With Other Medications

Eucalyptus has 878 moderate known drug interactions in our database — Levothyroxine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 878 No known interaction 1,952 (incl. Levothyroxine)
Taking anything else?

Check Another of Your Medications Against Eucalyptus

Covers the 2,830 medications we’ve checked against Eucalyptus. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Eucalyptus and Levothyroxine 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. 3 of them are worth acting on rather than waiting out — marked below.

  • Muscle weakness Worth acting on Additional detail

    Eucalyptus

    “Orally, diluted eucalyptus oil is generally well tolerated, but the undiluted oil can cause toxicity.

    Most Common Adverse Effects:

    Orally: Diarrhea, nausea, vomiting.

    Topically: Burning, itching, redness, stinging.

    Serious Adverse Effects (Rare):

    Orally: Signs of toxicity can occur with the undiluted oil at doses as low as 1 mL and include central nervous system depression, shallow respiration, rapid pulse, apnea, co…”

    Eucalyptus · Natural Medicines adverse-effect record, reported in depression.

    Levothyroxine

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

  • Wheezing Worth acting on Additional detail

    Eucalyptus

    “A case of IgE-mediated exacerbation of asthma and rhinitis symptoms has been reported in a patient who consumed eucalyptus. Similar worsening of symptoms occurred when the patient inhaled eucalyptus pollen.

    Occupational exposure to eucalyptus may cause allergic dermatitis.”

    Eucalyptus · Natural Medicines adverse-effect record, reported in asthma.

    2 sources cited
    1. 48957. Galdi, E., Perfetti, L., Calcagno, G., Marcotulli, M. C., and Moscato, G. Exacerbation of asthma related to Eucalyptus pollens and to herb infusion containing Eucalyptus. Monaldi Arch.Chest Dis. 2003;59(3):220-221.
    2. 98497. Paulsen E, Thormann H, Vestergaard L. Eucalyptus species as a cause of airborne allergic contact dermatitis. Contact Dermatitis. 2018;78(4):301-303.

    Levothyroxine

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

  • Seizures Worth acting on Additional detail

    Eucalyptus

    “Orally, eucalyptus oil can cause central nervous system depression, coma, and status epilepticus.

    Topically, orally, and by inhalation, eucalyptus oil has been associated with seizures. A systematic review describes the characteristics of 49 children and 61 adults with seizures associated with various routes of administration.”

    Eucalyptus · Natural Medicines adverse-effect record, reported in cluster headache.

    6 sources cited
    1. 12867. De Vincenzi M, Silano M, De Vincenzi A, et al. Constituents of aromatic plants: eucalyptol. Fitoterapia 2002;73:269-75. PubMed
    2. 48946. Tascini, C., Ferranti, S., Gemignani, G., Messina, F., and Menichetti, F. Clinical microbiological case: fever and headache in a heavy consumer of eucalyptus extract. Clin Microbiol.Infect. 2002;8(7):437, 445-437, 446. PubMed
    3. 48983. Spoerke, D. G., Vandenberg, S. A., Smolinske, S. C., Kulig, K., and Rumack, B. H. Eucalyptus oil: 14 cases of exposure. Vet Hum.Toxicol 1989;31(2):166-168.
    4. 107494. Panda PK, Sharawat IK, Panda P, Dawman L, Kasinathan A. Clinico-laboratory characteristics and outcome of patients with eucalyptus oil-induced/provoked seizures: A case series and systematic review of the published patients. Trop Doct 2021;51(4):518-522. PubMed
    5. 105028. Mathew T, John SK, Kamath V, et al. Essential oil related seizures (EORS): A multi-center prospective study on essential oils and seizures in adults. Epilepsy Res. 2021;173:106626. PubMed
    6. 107493. Dudipala SC, Mandapuram P, Ch LK. Eucalyptus Oil-Induced Seizures in Children: Case Reports and Review of the Literature. J Neurosci Rural Pract 2021;12(1):112-115. PubMed

    Levothyroxine

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

  • A fast or pounding heartbeat / Anxiety or restlessness Additional detail

    Eucalyptus

    Recorded for Eucalyptus in the same Natural Medicines adverse-effect record shown under Muscle weakness above.

    Levothyroxine

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

  • Fever Additional detail

    Eucalyptus

    Recorded for Eucalyptus in the same Natural Medicines adverse-effect record shown under Seizures above.

    Levothyroxine

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

  • Itching Additional detail

    Eucalyptus

    “Topically, eucalyptus pollen, leaves, oil, and the constituent eucalyptol can cause contact dermatitis in sensitive people. In some cases, symptoms respond to treatment with topical corticosteroids and tacrolimus. In one case report, transient local redness, burning, and irritation was reported in a 4-year-old child who was bathed in water containing eucalyptus oil.”

    Eucalyptus · Natural Medicines adverse-effect record, reported in dermatitis.

    6 sources cited
    1. 13303. Whitman BW, Ghazizadeh H. Eucalyptus oil: therapeutic and toxic aspects of pharmacology in humans and animals. J Paediatr Child Health 1994;30:190-1. PubMed
    2. 48931. Vilaplana, J. and Romaguera, C. Allergic contact dermatitis due to eucalyptol in an anti-inflammatory cream. Contact Dermatitis 2000;43(2):118.
    3. 92856. Gyldenløve M, Menné T, Thyssen JP. Eucalyptus contact allergy. Contact Dermatitis. 2014;71(5):303-304. PubMed
    4. 92858. Higgins C, Palmer A, Nixon R. Eucalyptus oil: contact allergy and safety. Contact Dermatitis. 2015;72(5):344-346. PubMed
    5. 92859. de Groot AC, Schmidt E. Eucalyptus oil and tea tree oil. Contact Dermatitis. 2015;73(6):381-386. PubMed
    6. 98497. Paulsen E, Thormann H, Vestergaard L. Eucalyptus species as a cause of airborne allergic contact dermatitis. Contact Dermatitis. 2018;78(4):301-303.

    Levothyroxine

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

  • Stomach pain Additional detail

    Eucalyptus

    “Orally, eucalyptus oil can cause nausea, vomiting, and diarrhea. Abdominal pain has been reported in a trial of the eucalyptus constituent eucalyptol for inflammatory bowel disease (IBD).”

    Eucalyptus · Natural Medicines adverse-effect record, reported in crohn disease.

    4 sources cited
    1. 48983. Spoerke, D. G., Vandenberg, S. A., Smolinske, S. C., Kulig, K., and Rumack, B. H. Eucalyptus oil: 14 cases of exposure. Vet Hum.Toxicol 1989;31(2):166-168.
    2. 48993. Tibballs, J. Clinical effects and management of eucalyptus oil ingestion in infants and young children. Med J Aust 8-21-1995;163(4):177-180. PubMed
    3. 48995. Webb, N. J. and Pitt, W. R. Eucalyptus oil poisoning in childhood: 41 cases in south-east Queensland. J Paediatr.Child Health 1993;29(5):368-371. PubMed
    4. 48936. Juergens, U. R. [Reducing the need for cortisone. Does eucalyptus oil work in asthma? (interview by Brigitte Moreano]. MMW.Fortschr Med 3-29-2001;143(13):14.

    Levothyroxine

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

  • Diarrhea Additional detail

    Eucalyptus

    Recorded for Eucalyptus in the same Natural Medicines adverse-effect record shown under Muscle weakness above.

    Levothyroxine

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

  • A skin rash Additional detail

    Eucalyptus

    Recorded for Eucalyptus in the same Natural Medicines adverse-effect record shown under Wheezing above.

    Levothyroxine

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

Showing the 10 most notable of 13 shared effects — ranked by how unusual each one is, not just whether both lists mention it.

Reported for Eucalyptus but not commonly for Levothyroxine: sore throat, drowsiness, a stuffy or runny nose and unsteadiness.

Effects for Levothyroxine come from the ADVERSE REACTIONS section of its FDA label; effects for Eucalyptus come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Eucalyptus in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

When used orally in amounts commonly found in foods. There is insufficient reliable information available about the safety of medicinal amounts of eucalyptus oil; avoid using.

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

How to take them

Some Levothyroxine Products Have a Food Rule — Eucalyptus Should Not Break It

At least one FDA label for a product containing Levothyroxine says to take it on an empty stomach. Most supplements — Eucalyptus included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Levothyroxine on its own and move Eucalyptus to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Levothyroxine products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Overlapping uses

What Levothyroxine Is Prescribed For, and What Eucalyptus Has Been Studied For

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

Levothyroxine is prescribed for: Levothyroxine replaces or supplements the thyroid hormone your body isn't making enough of. It's used for hypothyroidism — an underactive thyroid — in adults, children, and even newborns, whether the cause is the thyroid gland itself, the pituitary gland, or the hypothalamus in the brain. It's also used alongside surgery and radioiodine treatment in people with certain types of thyroid cancer, to help suppress the hormone that can stimulate cancer growth. It is not meant for weight loss, treating benign thyroid nodules in people who have enough iodine, or for hypothyroidism during recovery from a temporary condition called subacute thyroiditis.

Eucalyptus has been studied for:

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

    Eucalyptus for cancer

    Although there is interest in using oral eucalyptus for cancer, there is insufficient reliable information about the clinical effects of eucalyptus for this condition.

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 Levothyroxine on your own; if you are taking Eucalyptus for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Eucalyptus or Levothyroxine

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

This page covers Eucalyptus only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Levothyroxine page lists 50 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Tiratricol (major), Acetyl-l-carnitine (moderate), Alpha-lipoic Acid (moderate) and Ascophyllum Nodosum (moderate).

By severity: 2 major · 39 moderate · 9 minor.

From our pharmacist’s overview on the Levothyroxine page

“Levothyroxine replaces a hormone your body measures in tiny amounts, so small shifts in its blood level show up in how you feel, and I treat this list with genuine care. Nearly everything on it does one of two things: blocks the pill from being absorbed in the gut, the way everyday minerals like calcium do by binding it into complexes,…”

Reviewed by 2 · Jul 18, 2026

Open the Levothyroxine interaction page

One more smart check

Taking Eucalyptus as Part of a Dietary Supplement Product? Check It for Interactions

We hold 216 real supplement products containing Eucalyptus, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Eucalyptus. Even though Eucalyptus itself has no known interaction with Levothyroxine, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Eucalyptus and Levothyroxine 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 Eucalyptus
Top half

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

29 days ago today
Medication Levothyroxine
Top 10

#4 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 Eucalyptus reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Eucalyptus and Levothyroxine 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 Eucalyptus

What is Eucalyptus?

Eucalyptus
  • Cough and chest congestion
  • Colds and flu symptoms
  • Stuffy nose
  • Sore throat
  • Minor muscle and joint aches
  • Aromatherapy

Eucalyptus is best known for its strong-smelling oil used in vapor rubs, inhalants, and lozenges to ease coughs and congestion. It may provide mild, short-term relief of cold symptoms, but the oil is toxic if swallowed and must never be taken by mouth undiluted. Talk to a pharmacist or doctor before using it, especially in children, during pregnancy, or while breastfeeding.

Eucalyptus globulus · Myrtaceae · Leaves and essential oil · Essential oil, inhalants/vapor rubs, lozenges, tea, capsules, topical creams

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

Eucalyptus: dosing

There is no official standardized dose for eucalyptus. The right amount depends on the product and how it is used, such as a vapor rub, lozenge, inhalant, or tea.The safest approach is to follow the directions on the product label and not exceed them. Never swallow the concentrated essential oil, and always dilute it before putting it on the skin.

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

Read the full Eucalyptus monograph & all interactions
Medication

About Levothyroxine

What Is Levothyroxine Used For?

Brand names: Euthyrox, Levothroid, Unithroid, Synthroid, Levoxyl, Levo-T, Eltroxin, Estre, Levothyroxine, Novothyrox, Levolet

Levothyroxine replaces or supplements the thyroid hormone your body isn't making enough of. It's used for hypothyroidism — an underactive thyroid — in adults, children, and even newborns, whether the cause is the thyroid gland itself, the pituitary gland, or the hypothalamus in the brain.

It's also used alongside surgery and radioiodine treatment in people with certain types of thyroid cancer, to help suppress the hormone that can stimulate cancer growth. It is not meant for weight loss, treating benign thyroid nodules in people who have enough iodine, or for hypothyroidism during recovery from a temporary condition called subacute thyroiditis.

See full Levothyroxine drug information
Keep checking

Other Drugs & Eucalyptus

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

0Major
878Moderate
0Minor
1,951No known interaction
878 Moderate 1,951 No interaction
Moderate

878 interactions

Showing 60 of 878 moderate interactions — see all 878 on the Eucalyptus page.

No interaction 1,951 drugs checked — show the list

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

Showing the 60 most looked-up of 1,951 medications checked with no known interaction — see the full Eucalyptus list.

See the full Eucalyptus interactions page
See every supplement checked against Levothyroxine, ranked by severity
Evidence & sources

Eucalyptus References

The 23 references that drive our Eucalyptus 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. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
  2. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  3. De Vincenzi M, Silano M, De Vincenzi A, et al. Constituents of aromatic plants: eucalyptol. Fitoterapia 2002;73:269-75. PubMed
  4. Gray AM, Flatt PR. Antihyperglycemic actions of Eucalyptus globulus (Eucalyptus) are associated with pancreatic and extra-pancreatic effects in mice. J Nutr 1998;128:2319-23. PubMed
  5. Whitman BW, Ghazizadeh H. Eucalyptus oil: therapeutic and toxic aspects of pharmacology in humans and animals. J Paediatr Child Health 1994;30:190-1. PubMed
  6. Barker SC and Altman PM. An ex vivo, assessor blind, randomised, parallel group, comparative efficacy trial of the ovicidal activity of three pediculicides after a single application--melaleuca oil and lavender oil, eucalyptus oil and lemon tea tree oil,
  7. Vilaplana, J. and Romaguera, C. Allergic contact dermatitis due to eucalyptol in an anti-inflammatory cream. Contact Dermatitis 2000;43(2):118.
  8. Juergens, U. R. [Reducing the need for cortisone. Does eucalyptus oil work in asthma? (interview by Brigitte Moreano]. MMW.Fortschr Med 3-29-2001;143(13):14.
  9. Tascini, C., Ferranti, S., Gemignani, G., Messina, F., and Menichetti, F. Clinical microbiological case: fever and headache in a heavy consumer of eucalyptus extract. Clin Microbiol.Infect. 2002;8(7):437, 445-437, 446. PubMed
  10. Galdi, E., Perfetti, L., Calcagno, G., Marcotulli, M. C., and Moscato, G. Exacerbation of asthma related to Eucalyptus pollens and to herb infusion containing Eucalyptus. Monaldi Arch.Chest Dis. 2003;59(3):220-221.
  11. Spoerke, D. G., Vandenberg, S. A., Smolinske, S. C., Kulig, K., and Rumack, B. H. Eucalyptus oil: 14 cases of exposure. Vet Hum.Toxicol 1989;31(2):166-168.
  12. Jori, A., Bianchetti, A., Prestini, P. E., and Gerattini, S. Effect of eucalyptol (1,8-cineole) on the metabolism of other drugs in rats and in man. Eur.J Pharmacol 1970;9(3):362-366. PubMed
  13. Tibballs, J. Clinical effects and management of eucalyptus oil ingestion in infants and young children. Med J Aust 8-21-1995;163(4):177-180. PubMed
  14. Webb, N. J. and Pitt, W. R. Eucalyptus oil poisoning in childhood: 41 cases in south-east Queensland. J Paediatr.Child Health 1993;29(5):368-371. PubMed
  15. Gyldenløve M, Menné T, Thyssen JP. Eucalyptus contact allergy. Contact Dermatitis. 2014;71(5):303-304. 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 Eucalyptus and Levothyroxine Together: Common Questions

Is it safe to take Eucalyptus with Levothyroxine?
We do not list a known interaction between Eucalyptus and Levothyroxine. 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 Eucalyptus and Levothyroxine have any of the same side effects?
Yes — our sources link each of them separately to 10 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.
Should I take Eucalyptus and Levothyroxine at the same time of day?
At least one FDA label for a product containing Levothyroxine says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Levothyroxine on its own and move Eucalyptus to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.
Are Eucalyptus and Levothyroxine 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 Eucalyptus in each. That is a conversation for your prescriber, especially if Levothyroxine is being adjusted to a target.
How was the Eucalyptus and Levothyroxine combination checked?
Interactions in our licensed database are recorded against drug classes. Levothyroxine is filed under 3 classifications, and Eucalyptus has documented interactions with 7 drug classes — none of Levothyroxine's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Eucalyptus interact with any other medications?
Yes. Eucalyptus has 878 documented drug interactions in our database — Levothyroxine is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Levothyroxine interact with any supplements?
Yes. Levothyroxine has documented interactions with 50 supplements in our database — Eucalyptus is not one of them. The Levothyroxine 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

Eucalyptus monograph Uses, safety profile, and every drug interaction in one place Levothyroxine drug information The full plain-English guide to this medication Levothyroxine supplement interactions Every supplement checked against Levothyroxine, 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 23 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Levothyroxine and Eucalyptus?

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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.