Drug & supplement interaction

Devil's Claw + Levothyroxine

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

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Oct 4, 2026
The bottom line No known interaction

We found no known interaction between Devil's Claw 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

Devil's Claw 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 Devil's Claw 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.

Devil's Claw safety at a glance

Devil's Claw overall Use caution Generally well tolerated for short-term use in healthy adults, but it can cause digestive upset and isn't right for everyone.
Pregnancy Possibly Unsafe When used orally. Anecdotal evidence suggests that devil's claw has oxytocic effects in humans. Also, in vitro research shows that moderate to high doses of dev... Read the full pregnancy detail
Breastfeeding Avoid Avoid while breastfeeding because there is not enough safety information.

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 Devil's Claw? 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. Devil's Claw has documented interactions with 7 drug classes — the most serious being cytochrome p450 2c19 (cyp2c19) substrates (moderate), cytochrome p450 2c9 (cyp2c9) substrates (moderate) and cytochrome p450 3a4 (cyp3a4) 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

Devil's Claw Does Interact With Other Medications

Devil's Claw has 733 moderate, 72 minor 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 733 Minor 72 No known interaction 2,025 (incl. Levothyroxine)
Taking anything else?

Check Another of Your Medications Against Devil's Claw

Covers the 2,830 medications we’ve checked against Devil's Claw. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Devil's Claw 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.

  • Anxiety or restlessness Additional detail

    Devil's Claw

    “Rarely, anxiety has been reported in patients taking devil's claw.”

    Devil's Claw · Natural Medicines adverse-effect record, reported in anxiety.

    1 source cited
    1. 8608. Chrubasik S, Thanner J, Kunzel O, et al. Comparison of outcome measures during treatment with the proprietary Harpagophytum extract doloteffin in patients with pain in the lower back, knee or hip. Phytomedicine 2002;9:181-94. PubMed

    “In one case report, a 65-year-old female developed psychomotor agitation, nausea, and distress from euvolemic hyponatremia secondary to inappropriate secretion of antidiuretic hormone (SIADH) within 1 month of starting daily treatment with devil's claw. Within 5 days of discontinuing the product and receiving sodium replacement, the symptoms resolved.”

    Devil's Claw · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    1 source cited
    1. 96747. Carvalho RR, Donadel CD, Cortez AF, Valviesse VR, Vianna PF, Correa BB. J Bras Nefrol. 2017 Mar;39(1):79-81.

    Levothyroxine

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

  • Trouble sleeping / Headache Additional detail

    Devil's Claw

    “In a trial of devil's claw, one patient withdrew after 4 days of therapy due to a throbbing frontal headache, as well as tinnitus, anorexia, and loss of taste. Rarely, dizziness, somnolence, and insomnia have been reported. It is unclear if these symptoms were caused by devil's claw.”

    Devil's Claw · Natural Medicines adverse-effect record, reported in anorexia.

    3 sources cited
    1. 8613. Grahame R, Robinson BV. Devils's claw (Harpagophytum procumbens): pharmacological and clinical studies. Ann Rheum Dis 1981;40:632. PubMed
    2. 47116. Laudahn, D. and Walper, A. Efficacy and tolerance of Harpagophytum extract LI 174 in patients with chronic non-radicular back pain. Phytother.Res. 2001;15(7):621-624.
    3. 47169. Chrubasik S, Model A, Black A, and et al. A randomized double-blind pilot study comparing Doloteffin® and Vioxx® in the treatment of low back pain. Rheumatology 2003;42:141-148.

    Levothyroxine

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

  • Diarrhea Additional detail

    Devil's Claw

    “Gastrointestinal side effects, including mild gastrointestinal upset, diarrhea, anorexia, acid reflux, or loss of taste, have been reported in some individuals receiving devil's claw, especially at high doses.”

    Devil's Claw · Natural Medicines adverse-effect record, reported in anorexia.

    6 sources cited
    1. 6472. Chantre P, Cappelaere A, Leblan D, et al. Efficacy and tolerance or Harpagophytum procumbens versus diacerhein in treatment of osteoarthritis. Phytomedicine 2000;7:177-83.
    2. 8608. Chrubasik S, Thanner J, Kunzel O, et al. Comparison of outcome measures during treatment with the proprietary Harpagophytum extract doloteffin in patients with pain in the lower back, knee or hip. Phytomedicine 2002;9:181-94. PubMed
    3. 8613. Grahame R, Robinson BV. Devils's claw (Harpagophytum procumbens): pharmacological and clinical studies. Ann Rheum Dis 1981;40:632. PubMed
    4. 14332. Wegener T, Lupke NP. Treatment of patients with arthrosis of hip or knee with an aqueous extract of devil's claw (Harpagophytum procumbens DC). Phytother Res 2003;17:1165-72.
    5. 14418. Chrubasik S, Kunzel O, Thanner J, et al. A 1-year follow-up after a pilot study with Doloteffin for low back pain. Phytomedicine 2005;12:1-9. PubMed
    6. 47112. Chrubasik, S., Junck, H., Breitschwerdt, H., Conradt, C., and Zappe, H. Effectiveness of Harpagophytum extract WS 1531 in the treatment of exacerbation of low back pain: a randomized, placebo-controlled, double- blind study. Eur.J Anaesthesiol. 1999;16(2 DOI

    Levothyroxine

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

  • Nausea Additional detail

    Devil's Claw

    Recorded for Devil's Claw in the same Natural Medicines adverse-effect record shown under Anxiety or restlessness above.

    Levothyroxine

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

Reported for Devil's Claw but not commonly for Levothyroxine: bleeding in the gut, stomach upset, a change in taste and raised blood pressure.

Effects for Levothyroxine come from the ADVERSE REACTIONS section of its FDA label; effects for Devil's Claw 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

Devil's Claw in Pregnancy & Breastfeeding

Pregnancy Possibly Unsafe

When used orally. Anecdotal evidence suggests that devil's claw has oxytocic effects in humans. Also, in vitro research shows that moderate to high doses of devil's claw root extract induce contractions of isolated uterine muscle from pregnant and nonpregnant rats; 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 — Devil's Claw Should Not Break It

At least one FDA label for a product containing Levothyroxine says to take it on an empty stomach. Most supplements — Devil's Claw 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 Devil's Claw 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.

From our Q&A

Questions About Devil's Claw 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 Devil's Claw 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 Devil's Claw 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 Devil's Claw as Part of a Dietary Supplement Product? Check It for Interactions

We hold 585 real supplement products containing Devil's Claw, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Devil's Claw. Even though Devil's Claw 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 Devil's Claw 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 Devil's Claw
Top 25%

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

29 days ago today
Medication Levothyroxine
Top 10

#2 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 Devil's Claw reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified October 4, 2026. The Devil's Claw and Levothyroxine records this page draws on were last updated July 11, 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 Devil's Claw

What is Devil's Claw?

Devil's Claw
  • Osteoarthritis pain
  • Lower back pain
  • Joint pain and stiffness
  • General inflammation
  • Digestive upset and loss of appetite

Devil's claw is a southern African plant used mainly for arthritis and back pain, and some studies suggest it may help ease these types of discomfort. The evidence is moderate at best, and product strength varies, so talk with your pharmacist or doctor before trying it, especially if you have a health condition or take medications.

Harpagophytum procumbens · Pedaliaceae · Dried secondary (tuberous) roots · Capsules, tablets, dried root, tea, liquid extracts, and tinctures

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

Devil's Claw: dosing

There is no single official dose for devil's claw. Many products are standardized to their harpagoside content, but the amount varies a lot from one brand to another.The safest approach is to follow the directions on the product label and not take more than recommended.

From our Devil's Claw monograph — the full record covers uses, side effects and every documented interaction.

Read the full Devil's Claw 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 thyroid hormone when your body does not make enough. The oral products (tablets, capsules and oral solution) treat hypothyroidism, which can be present from birth or develop later. They are also used alongside surgery and radioiodine therapy for thyrotropin-dependent well-differentiated thyroid cancer.

Levothyroxine Sodium injection (given intravenously) is used only for myxedema coma, a life-threatening emergency from severe hypothyroidism. Age ranges differ by product. For example, Tirosint capsules are labeled for adults and children 6 years and older.

Most-Reported Side Effects for Levothyroxine

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 26,588 reports
Nausea 22,608 reports
Headache 19,408 reports
Diarrhea 18,758 reports
Dyspnea 16,725 reports
See full Levothyroxine drug information
Keep checking

Other Drugs & Devil's Claw

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

0Major
733Moderate
72Minor
2,024No known interaction
733 Moderate 72 Minor 2,024 No interaction
Moderate

733 interactions

Showing 60 of 733 moderate interactions — see all 733 on the Devil's Claw page.

Minor

72 interactions

Showing 60 of 72 minor interactions — see all 72 on the Devil's Claw page.

No interaction 2,024 drugs checked — show the list

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

Showing the 60 most looked-up of 2,024 medications checked with no known interaction — see the full Devil's Claw list.

See the full Devil's Claw interactions page
See every supplement checked against Levothyroxine, ranked by severity
Evidence & sources

Devil's Claw References

The 18 references that drive our Devil's Claw 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. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  2. Shaw D, Leon C, Kolev S, Murray V. Traditional remedies and food supplements: a 5-year toxicological study (1991-1995). Drug Saf 1997;17:342-56.
  3. Chantre P, Cappelaere A, Leblan D, et al. Efficacy and tolerance or Harpagophytum procumbens versus diacerhein in treatment of osteoarthritis. Phytomedicine 2000;7:177-83.
  4. Chrubasik S, Thanner J, Kunzel O, et al. Comparison of outcome measures during treatment with the proprietary Harpagophytum extract doloteffin in patients with pain in the lower back, knee or hip. Phytomedicine 2002;9:181-94. PubMed
  5. Circosta C, Occhiuto F, Ragusa S, et al. A drug used in traditional medicine: Harpagophytum procumbens DC. II. Cardiovascular activity. J Ethnopharmacol 1984;11:259-74. PubMed
  6. Grahame R, Robinson BV. Devils's claw (Harpagophytum procumbens): pharmacological and clinical studies. Ann Rheum Dis 1981;40:632. PubMed
  7. 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
  8. Wegener T, Lupke NP. Treatment of patients with arthrosis of hip or knee with an aqueous extract of devil's claw (Harpagophytum procumbens DC). Phytother Res 2003;17:1165-72.
  9. Chrubasik S, Kunzel O, Thanner J, et al. A 1-year follow-up after a pilot study with Doloteffin for low back pain. Phytomedicine 2005;12:1-9. PubMed
  10. Romiti N, Tramonti G, Corti A, Chieli E. Effects of Devil's Claw (Harpagophytum procumbens) on the multidrug transporter ABCB1/P-glycoprotein. Phytomedicine 2009;16:1095-100. PubMed
  11. Chrubasik, S., Junck, H., Breitschwerdt, H., Conradt, C., and Zappe, H. Effectiveness of Harpagophytum extract WS 1531 in the treatment of exacerbation of low back pain: a randomized, placebo-controlled, double- blind study. Eur.J Anaesthesiol. 1999;16(2 DOI
  12. Laudahn, D. and Walper, A. Efficacy and tolerance of Harpagophytum extract LI 174 in patients with chronic non-radicular back pain. Phytother.Res. 2001;15(7):621-624.
  13. Belaiche P. Etude clinique de 630 cas d'artrose traites par le nebulisat aqueux d'Harpagophytum procumbens (Radix). Phytotherapy 1982;1:22-28.
  14. Chrubasik S, Model A, Black A, and et al. A randomized double-blind pilot study comparing Doloteffin® and Vioxx® in the treatment of low back pain. Rheumatology 2003;42:141-148.
  15. Cuspidi C, Sala C, Tadic M, et al. Systemic hypertension induced by Harpagophytum procumbens (devil's claw): a case report. J Clin Hypertens (Greenwich) 2015;17(11):908-10.

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 Devil's Claw and Levothyroxine Together: Common Questions

Is it safe to take Devil's Claw with Levothyroxine?
We do not list a known interaction between Devil's Claw 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 Devil's Claw and Levothyroxine 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.
Should I take Devil's Claw 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 Devil's Claw 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.
How was the Devil's Claw and Levothyroxine combination checked?
Interactions in our licensed database are recorded against drug classes. Levothyroxine is filed under 3 classifications, and Devil's Claw 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 Devil's Claw interact with any other medications?
Yes. Devil's Claw has 805 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 — Devil's Claw 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

Devil's Claw 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 18 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Levothyroxine and Devil's Claw?

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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.