Drug & supplement interaction

Chaparral + Levothyroxine, Liothyronine

Levothyroxine, Liothyronine brand name: Armour Thyroid.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Chaparral and Levothyroxine, Liothyronine 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.

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Interaction report

Chaparral and Levothyroxine, Liothyronine

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, Liothyronine and Chaparral 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.

Chaparral safety at a glance

Chaparral overall Avoid Chaparral has been linked to serious liver and kidney toxicity and is not recommended.
Pregnancy Likely Unsafe When used orally. There are several reports of serious poisoning, acute hepatitis, and kidney and liver damage, including irreversible renal and hepatic failure... Read the full pregnancy detail
Breastfeeding Likely Unsafe When used orally. There are several reports of serious poisoning, acute hepatitis, and kidney and liver damage, including irreversible renal and hepatic failure... 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, Liothyronine and Chaparral? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Levothyroxine, Liothyronine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Levothyroxine, Liothyronine is filed under 3 classifications — including thyroid hormone, oral drugs. Chaparral has documented interactions with 1 drug class — the most serious being hepatotoxic drugs (moderate) — and none of Levothyroxine, Liothyronine’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

Chaparral Does Interact With Other Medications

Chaparral has 370 moderate known drug interactions in our database — Levothyroxine, Liothyronine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 370 No known interaction 2,460 (incl. Levothyroxine, Liothyronine)
Taking anything else?

Check Another of Your Medications Against Chaparral

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

What to actually watch for

What Chaparral Itself Has Been Linked To

This is not an interaction — nothing below involves Levothyroxine, Liothyronine. It is the side-effect record for Chaparral on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Chaparral, this list is the first place to look. 2 entries are worth acting on rather than waiting out — marked below.

  • Yellowing of the skin or eyes / Liver problems Worth acting on Additional detail

    “Chaparral is generally regarded as unsafe for use. Any benefits of therapy may not outweigh the risk of toxicity. Orally, chaparral can cause hepatoxicity, resulting in jaundice, fatigue, right upper quadrant abdominal pain, dark urine, light stools, nausea, diarrhea, weight loss, fever, and anorexia.”

    Chaparral · Natural Medicines adverse-effect record, reported in anorexia.

    6 sources cited
    1. 568. Smith BC, Desmond PV. Acute hepatitis induced by ingestion of the herbal medication chaparral. Aust N Z J Med 1993;23:526.. PubMed
    2. 569. Gordon DW, Rosenthal G, Hart J, et al. Chaparral ingestion: the broadening spectrum of liver injury caused by herbal medications. JAMA 1995;273:489-90.
    3. 570. Batchelor WB, Heathcote J, Wanless IR. Chaparral-induced hepatic injury. Am J Gastroenterol 1995;90:831-3.
    4. 571. Katz M, Saibil F. Herbal hepatitis: subacute hepatic necrosis secondary to chaparral leaf. J Clin Gastroenterol 1990;12:203-6.
    5. 3497. Sheikh NM, Philen RM, Love LA. Chaparral-associated hepatotoxicity. Arch Intern Med 1997;157:913-9. DOI
    6. 11121. Chaparral-induced toxic hepatitis-California and Texas, 1992. MMWR Morb Mortal Wkly Rep 1992;41:812-4.. DOI

    “Orally, chaparral can cause hepatoxicity, resulting in jaundice, fatigue, right upper quadrant abdominal pain, dark urine, light stools, nausea, diarrhea, weight loss, fever, and anorexia. It can also cause cirrhosis, cholestasis, cholangitis, acute hepatitis, and liver failure Multiple cases of severe hepatotoxicity have been reported, including at least two cases requiring liver transplant.

    The nordihydroguaiaretic…”

    Chaparral · Natural Medicines adverse-effect record, reported in anorexia.

    6 sources cited
    1. 3497. Sheikh NM, Philen RM, Love LA. Chaparral-associated hepatotoxicity. Arch Intern Med 1997;157:913-9. DOI
    2. 568. Smith BC, Desmond PV. Acute hepatitis induced by ingestion of the herbal medication chaparral. Aust N Z J Med 1993;23:526.. PubMed
    3. 569. Gordon DW, Rosenthal G, Hart J, et al. Chaparral ingestion: the broadening spectrum of liver injury caused by herbal medications. JAMA 1995;273:489-90.
    4. 570. Batchelor WB, Heathcote J, Wanless IR. Chaparral-induced hepatic injury. Am J Gastroenterol 1995;90:831-3.
    5. 571. Katz M, Saibil F. Herbal hepatitis: subacute hepatic necrosis secondary to chaparral leaf. J Clin Gastroenterol 1990;12:203-6.
    6. 11121. Chaparral-induced toxic hepatitis-California and Texas, 1992. MMWR Morb Mortal Wkly Rep 1992;41:812-4.. DOI
  • Kidney problems Worth acting on Additional detail

    “Orally, chaparral can cause kidney failure. Consumption of chaparral tea has been associated with cystic renal disease and cystic adenocarcinoma of the kidney. In one case report, consumption of 3-4 cups of chaparral tea daily was associated with these symptoms.”

    Chaparral · Natural Medicines adverse-effect record, reported in kidney failure.

    2 sources cited
    1. 3497. Sheikh NM, Philen RM, Love LA. Chaparral-associated hepatotoxicity. Arch Intern Med 1997;157:913-9. DOI
    2. 11129. Smith AY, Feddersen RM, Gardner KD Jr, Davis CJ Jr. Cystic renal cell carcinoma and acquired renal cystic disease associated with consumption of chaparral tea: a case report. J Urol 1994;152:2089-91.. PubMed
  • Weight loss / Reduced appetite / Fever / Stomach pain / Tiredness / Diarrhea Additional detail

    Recorded for Chaparral in the same Natural Medicines adverse-effect record shown under Yellowing of the skin or eyes / Liver problems above.

  • A skin rash Additional detail

    “Topically, chaparral can cause contact dermatitis.”

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

    3 sources cited
    1. 10417. Heron S, Yarnell E. The safety of low-dose Larrea tridentata (DC) Coville (creosote bush or chaparral): a retrospective clinical study. J Altern Complement Med 2001;7:175-85..
    2. 11128. Shasky DR. Contact dermatitis from Larrea tridentata (creosote bush). J Am Acad Dermatol 1986;15:302.. PubMed
    3. 41434. Leonforte, J. F. Contact dermatitis from Larrea (creosote bush). J Am Acad.Dermatol. 1986;14(2 Pt 1):202-207. PubMed

Showing the 10 most notable of 11 recorded effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

Everything above comes from the Natural Medicines adverse-effect record for Chaparral — expand a row for the licensed statement it rests on. We haven’t matched Levothyroxine, Liothyronine to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Levothyroxine, Liothyronine.

Special populations

Chaparral in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Unsafe

When used orally. There are several reports of serious poisoning, acute hepatitis, and kidney and liver damage, including irreversible renal and hepatic failure. Advise patients not to use products containing chaparral.

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

Everything else you take

See Every Supplement That Interacts With Levothyroxine, Liothyronine

This page covers Chaparral only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Levothyroxine, Liothyronine 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, Liothyronine page

“For anyone taking levothyroxine or liothyronine (Armour Thyroid), this list earns real caution, not just a passing glance. Most of these 50 ingredients pull in one of two directions.”

Reviewed by 2 · Jul 18, 2026

Open the Levothyroxine, Liothyronine interaction page

One more smart check

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

We hold 83 real supplement products containing Chaparral, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Chaparral. Even though Chaparral itself has no known interaction with Levothyroxine, Liothyronine, 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 Chaparral and Levothyroxine, Liothyronine 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 Chaparral
Steady interest

#1,014 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Levothyroxine, Liothyronine
Top 5%

#61 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 Chaparral reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Chaparral and Levothyroxine, Liothyronine 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 Chaparral

What is Chaparral?

Chaparral
  • Pain and inflammation
  • Skin conditions
  • Antioxidant/general wellness
  • Infections
  • Traditional 'detox' remedies

Chaparral is a desert shrub long used in traditional medicine, but there is no reliable proof it treats any condition. It has been linked to serious and sometimes irreversible liver and kidney damage, and the FDA has warned against using it. Because of these safety concerns, we recommend avoiding chaparral.

Larrea tridentata · Zygophyllaceae · Leaves and twigs · Tea, capsules, tablets, tinctures, topical salves

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

Chaparral: dosing

There is no safe or established dose for chaparral. For chaparral specifically, the best advice is to avoid it.

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

Read the full Chaparral monograph & all interactions
Medication

About Levothyroxine, Liothyronine

Most-Reported Side Effects for Levothyroxine, Liothyronine

From FAERS, the FDA’s public side-effect reporting system (15 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 4 reports
Asthenia 3 reports
Dizziness 3 reports
Arthralgia 2 reports
Disorientation 2 reports
Keep checking

Other Drugs & Chaparral

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

0Major
370Moderate
0Minor
2,459No known interaction
370 Moderate 2,459 No interaction
Moderate

370 interactions

Showing 60 of 370 moderate interactions — see all 370 on the Chaparral page.

No interaction 2,459 drugs checked — show the list

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

Showing the 60 most looked-up of 2,459 medications checked with no known interaction — see the full Chaparral list.

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

Chaparral References

The 16 references that drive our Chaparral 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. Smith BC, Desmond PV. Acute hepatitis induced by ingestion of the herbal medication chaparral. Aust N Z J Med 1993;23:526.. PubMed
  2. Gordon DW, Rosenthal G, Hart J, et al. Chaparral ingestion: the broadening spectrum of liver injury caused by herbal medications. JAMA 1995;273:489-90.
  3. Batchelor WB, Heathcote J, Wanless IR. Chaparral-induced hepatic injury. Am J Gastroenterol 1995;90:831-3.
  4. Katz M, Saibil F. Herbal hepatitis: subacute hepatic necrosis secondary to chaparral leaf. J Clin Gastroenterol 1990;12:203-6.
  5. Klepser TB, Klepser ME. Unsafe and potentially safe herbal therapies. Am J Health Syst Pharm 1999;56:125-38. PubMed
  6. Sheikh NM, Philen RM, Love LA. Chaparral-associated hepatotoxicity. Arch Intern Med 1997;157:913-9. DOI
  7. Heron S, Yarnell E. The safety of low-dose Larrea tridentata (DC) Coville (creosote bush or chaparral): a retrospective clinical study. J Altern Complement Med 2001;7:175-85..
  8. Chaparral-induced toxic hepatitis-California and Texas, 1992. MMWR Morb Mortal Wkly Rep 1992;41:812-4.. DOI
  9. Estes JD, Stolpman D, Olyaei A, et al. High prevalence of potentially hepatotoxic herbal supplement use in patients with fulminant hepatic failure. Arch Surg 2003;138:852-8.. PubMed
  10. Lambert JD, Zhao D, Meyers RO, et al. Nordihydroguaiaretic acid: hepatotoxicity and detoxification in the mouse. Toxicon 2002;40:1701-8.. PubMed
  11. Shasky DR. Contact dermatitis from Larrea tridentata (creosote bush). J Am Acad Dermatol 1986;15:302.. PubMed
  12. Smith AY, Feddersen RM, Gardner KD Jr, Davis CJ Jr. Cystic renal cell carcinoma and acquired renal cystic disease associated with consumption of chaparral tea: a case report. J Urol 1994;152:2089-91.. PubMed
  13. Kauma, H., Koskela, R., Makisalo, H., Autio-Harmainen, H., Lehtola, J., and Hockerstedt, K. Toxic acute hepatitis and hepatic fibrosis after consumption of chaparral tablets. Scand.J Gastroenterol. 2004;39(11):1168-1171. PubMed
  14. Leonforte, J. F. Contact dermatitis from Larrea (creosote bush). J Am Acad.Dermatol. 1986;14(2 Pt 1):202-207. PubMed
  15. Alderman, S., Kailas, S., Goldfarb, S., Singaram, C., and Malone, D. G. Cholestatic hepatitis after ingestion of chaparral leaf: confirmation by endoscopic retrograde cholangiopancreatography and liver biopsy. J Clin.Gastroenterol. 1994;19(3):242-247.

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 Chaparral and Levothyroxine, Liothyronine Together: Common Questions

Is it safe to take Chaparral with Levothyroxine, Liothyronine?
We do not list a known interaction between Chaparral and Levothyroxine, Liothyronine. 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.
How was the Chaparral and Levothyroxine, Liothyronine combination checked?
Interactions in our licensed database are recorded against drug classes. Levothyroxine, Liothyronine is filed under 3 classifications, and Chaparral has documented interactions with 1 drug class — none of Levothyroxine, Liothyronine'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 Chaparral interact with any other medications?
Yes. Chaparral has 370 documented drug interactions in our database — Levothyroxine, Liothyronine 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, Liothyronine interact with any supplements?
Yes. Levothyroxine, Liothyronine has documented interactions with 50 supplements in our database — Chaparral is not one of them. The Levothyroxine, Liothyronine 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

Chaparral monograph Uses, safety profile, and every drug interaction in one place Levothyroxine, Liothyronine supplement interactions Every supplement checked against Levothyroxine, Liothyronine, 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 16 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Levothyroxine, Liothyronine and Chaparral?

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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.