Drug & supplement interaction

Ergot + Levothyroxine

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

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 Ergot 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

Ergot 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 Ergot 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.

Ergot safety at a glance

Ergot overall Avoid Crude ergot is toxic and can cause serious, even fatal, poisoning; it should not be used as a supplement.
Pregnancy Unsafe When used orally due to risk for toxicity and stillbirth; avoid using. Read the full pregnancy detail
Breastfeeding Unsafe When used orally due to risk for toxicity and stillbirth; avoid using. 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 Ergot? 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. Ergot has documented interactions with 4 drug classes — the most serious being cytochrome p450 3a4 (cyp3a4) inhibitors (moderate), ergot derivatives (moderate) and serotonergic drugs (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

Ergot Does Interact With Other Medications

Ergot has 462 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 462 No known interaction 2,368 (incl. Levothyroxine)
Taking anything else?

Check Another of Your Medications Against Ergot

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

What to actually watch for

No Interaction Found — But Data Suggests Ergot 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. One of them is worth acting on rather than waiting out — marked below.

  • Seizures Worth acting on Additional detail

    Ergot

    “Orally, ergot can cause gastrointestinal symptoms such as nausea and abdominal pain. Weakness, muscle pain of the extremities, and numbness and tingling of the fingers and toes may also occur (9). Symptoms of acute overdose include nausea, vomiting, diarrhea, extreme thirst, coldness, tingling and itching of the skin, a rapid and weak pulse, hypotension, shock, confusion, seizures, unconsciousness, and death (9).

    Chr…”

    Ergot · Natural Medicines adverse-effect record, reported in diarrhea.

    3 sources cited
    1. 9. Martindale W. Martindale the Extra Pharmacopoeia. Pharmaceutical Press, 1999.
    2. 11163. Eadie MJ. Convulsive ergotism: epidemics of the serotonin syndrome? Lancet Neurol 2003;2:429-34. PubMed
    3. 11164. Etzel RA. Mycotoxins. JAMA 2002;287:425-7.

    “Symptoms of acute ergot oral overdose include nausea, vomiting, diarrhea, extreme thirst, coldness, tingling and itching of the skin, a rapid and weak pulse, hypotension, shock, confusion, seizures, unconsciousness, and death (9).”

    Ergot · Natural Medicines adverse-effect record, reported in diarrhea.

    1 source cited
    1. 9. Martindale W. Martindale the Extra Pharmacopoeia. Pharmaceutical Press, 1999.

    Levothyroxine

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

  • Sweating / Fever Additional detail

    Ergot

    “Orally, chronic toxicity from cumulative ergot doses over a short period of time can present as a convulsive form of ergotism. Symptoms include muscle spasms in the trunk and limbs, painful involuntary flexion of the fingers and wrists, and either flexion or extension of the ankles. Sweating, fever, muscle stiffness, twitching and seizures have also been reported (9,11163).”

    Ergot · Natural Medicines adverse-effect record, reported in epilepsy.

    2 sources cited
    1. 9. Martindale W. Martindale the Extra Pharmacopoeia. Pharmaceutical Press, 1999.
    2. 11163. Eadie MJ. Convulsive ergotism: epidemics of the serotonin syndrome? Lancet Neurol 2003;2:429-34. PubMed

    Levothyroxine

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

  • Itching Additional detail

    Ergot

    Recorded for Ergot 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 ›

  • Stomach pain / Diarrhea / Vomiting / Nausea Additional detail

    Ergot

    “Orally, ergot can cause gastrointestinal symptoms such as nausea, vomiting, diarrhea, and abdominal pain (9).”

    Ergot · Natural Medicines adverse-effect record, reported in diarrhea.

    1 source cited
    1. 9. Martindale W. Martindale the Extra Pharmacopoeia. Pharmaceutical Press, 1999.

    Levothyroxine

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

  • Tiredness Additional detail

    Ergot

    “Orally, ergot can cause drowsiness, delirium, lethargy, mental changes, and visual disturbances (9,11163).”

    Ergot · Natural Medicines adverse-effect record, reported in delirium.

    2 sources cited
    1. 9. Martindale W. Martindale the Extra Pharmacopoeia. Pharmaceutical Press, 1999.
    2. 11163. Eadie MJ. Convulsive ergotism: epidemics of the serotonin syndrome? Lancet Neurol 2003;2:429-34. PubMed

    Levothyroxine

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

Reported for Ergot but not commonly for Levothyroxine: blurred vision, joint or muscle stiffness, muscle pain and low blood pressure.

Effects for Levothyroxine come from the ADVERSE REACTIONS section of its FDA label; effects for Ergot 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

Ergot in Pregnancy & Breastfeeding

Pregnancy And Lactation Unsafe

When used orally due to risk for toxicity and stillbirth; 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 — Ergot Should Not Break It

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

How much people look this up

Where Ergot 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 Ergot
Steady interest

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

What is Ergot?

Ergot
  • Heavy menstrual or uterine bleeding
  • Bleeding after childbirth
  • Migraine headaches
  • Stimulating uterine contractions

Ergot is a toxic fungus that grows on rye and contains powerful chemicals (ergot alkaloids) that strongly narrow blood vessels and squeeze the uterus. Because raw ergot is poisonous and the dose is impossible to control safely, it should never be used as a home remedy or supplement. Some purified ergot chemicals are used as prescription drugs under strict medical supervision, but the crude herb is not safe to take.

Claviceps purpurea · Clavicipitaceae · The fungal mass (sclerotium) that grows on rye and other grasses · Historically used as crude dried fungus; purified ergot alkaloids are available only as prescription medicines (not as a dietary supplement)

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

Ergot: dosing

There is no safe established dose of crude ergot for self-care, and it should not be taken as a supplement. The amount of active chemical in the raw fungus varies and cannot be measured reliably at home, which makes poisoning very easy.The only safe way ergot chemicals are used is as purified, carefully measured prescription medicines given and monitored by a healthcare professional. Do not try to make or take any ergot preparation on your own.

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

Read the full Ergot 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 & Ergot

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

0Major
462Moderate
0Minor
2,367No known interaction
462 Moderate 2,367 No interaction
Moderate

462 interactions

Showing 60 of 462 moderate interactions — see all 462 on the Ergot page.

No interaction 2,367 drugs checked — show the list

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

Showing the 60 most looked-up of 2,367 medications checked with no known interaction — see the full Ergot list.

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

Ergot References

The 4 references that drive our Ergot 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. Martindale W. Martindale the Extra Pharmacopoeia. Pharmaceutical Press, 1999.
  2. Singhal AB, Caviness VS, Begleiter AF, et al. Cerebral vasoconstriction and stroke after use of serotonergic drugs. Neurology 2002;58:130-3. PubMed
  3. Eadie MJ. Convulsive ergotism: epidemics of the serotonin syndrome? Lancet Neurol 2003;2:429-34. PubMed
  4. Etzel RA. Mycotoxins. JAMA 2002;287:425-7.

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 Ergot and Levothyroxine Together: Common Questions

Is it safe to take Ergot with Levothyroxine?
We do not list a known interaction between Ergot 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 Ergot and Levothyroxine have any of the same side effects?
Yes — our sources link each of them separately to 9 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 Ergot 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 Ergot 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 Ergot and Levothyroxine combination checked?
Interactions in our licensed database are recorded against drug classes. Levothyroxine is filed under 3 classifications, and Ergot has documented interactions with 4 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 Ergot interact with any other medications?
Yes. Ergot has 462 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 — Ergot 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

Ergot 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 4 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Levothyroxine and Ergot?

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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.