Medication interaction hub

What Supplements Interact with Thyroid Hormone?

Thyroid Hormone brand name: Etwon. Every interaction below applies to the brands too.

38 Interactions 2 Major 26 Moderate 10 Minor
Curated & coded by · Clinical Pharmacist · Updated September 24, 2026

Drug–supplement interaction data sourced from Natural Medicines Pro, the licensed clinical database from TRC Healthcare / Therapeutic Research, with additional analysis by the HelloPharmacist Pharmacist Team. Our sources · Editorial policy

What is this page for?

One answer, for one medication: what supplements and herbal products interact with Thyroid Hormone? Every vitamin, herb, and supplement ingredient we’ve checked against it is on this page, ranked by severity, each linking to the full report for that exact pair.

This page covers supplement interactions only — to check Thyroid Hormone against your other medications, use the drug–drug interaction checker. Educational information from our licensed clinical databases, not medical advice. Our editorial policy

HelloPharmacist Bottom Line
Our Pharmacist Explains
What is this? The interaction data in the HelloPharmacist supplement database is licensed from Natural Medicines Pro by TRC Healthcare (Therapeutic Research). HelloPharmacist pharmacists often add our own analysis and context on top of that licensed data — such as this Bottom Line summary and the notes on individual interaction pages — and any such commentary is noted as ours.

The riskiest pairing on this page is tiratricol, which is itself a thyroid compound, so taking it alongside thyroid hormone (Etwon) stacks two doses of the same signal. It shares the list's only two major ratings with activated charcoal, which soaks up medication in the gut before the body can absorb it. With 38 ingredients on file and those two at the top, this is a list I would read with genuine wariness rather than a shrug.

Of the rest, 26 rate moderate and 10 minor, and they sort into two broad camps. Twenty-one ingredients act on thyroid function itself, some boosting it, like ashwagandha, others blunting the replacement dose. The remainder interfere with how well swallowed pills absorb, so bulk fibers and charcoal products belong well separated in time from the tablet. Thyroid dosing is tuned finely, and even a modest shift in either direction tends to show up as real symptoms.

— , Clinical Pharmacist · July 18, 2026

Major 2 Moderate 26 Minor 10 No known interaction 1,414

This box checks one ingredient at a time (like turmeric or magnesium). Taking a supplement product with a whole label of ingredients? Search the product instead — we check every ingredient on it ↓

Most Viewed Ingredient Interactions

Thyroid Hormone: Top Interactions at a Glance

The Thyroid Hormone supplement & herbal interactions people checked most in the last 24 hours, colored by severity. Tap any ingredient to open the full report for that pair.

Showing the 12 highest-ranked of 38 interacting ingredients — plus 1,414 more checked with no known interaction. See the complete ranked list.

Start here

The Most-Checked Thyroid Hormone Combinations Today

The Thyroid Hormone + supplement pages people viewed most in the last 24 hours (resets at midnight). Open any card for the full report.

Moderate Likelihood Probable L-carnitine + Thyroid Hormonei

Theoretically, L-carnitine might decrease the effectiveness of thyroid hormone replacement.

Read the full interaction Moderate Likelihood Possible Sea Moss + Thyroid Hormonei

Due to its iodine content, sea moss might alter the effects of thyroid hormone.

Read the full interaction Minor Likelihood Possible Bacopa + Thyroid Hormonei

Theoretically, bacopa might have additive effects when used with thyroid hormone.

Read the full interaction Moderate Likelihood Possible Fucus Vesiculosus + Thyroid Hormonei

Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.

Read the full interaction Moderate Likelihood Possible Lemon Balm + Thyroid Hormonei

Theoretically, lemon balm might interfere with thyroid hormone replacement therapy.

Read the full interaction Moderate Likelihood Possible Horseradish + Thyroid Hormonei

Theoretically, horseradish might interfere with the effects of thyroid hormone.

Read the full interaction
The complete list

Every Supplement Checked Against Thyroid Hormone

All 1,452 ingredients in our database, ranked by severity — 38 with a Thyroid Hormone interaction on file and 1,414 with none found. Filter by severity or search any ingredient; hover the for what each ingredient is.

Looking for an interaction with a specific supplement product? Search products instead ↓

Straight answers

Can You Take It With Thyroid Hormone?

One-line answers, one card per combination — scroll through today’s 20 and tap any card for the full report. A different set rotates in daily until every combination has had its turn.

Can you take L-carnitine with Thyroid Hormone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, L-carnitine might decrease the effectiveness of thyroid hormone replacement.

Full L-carnitine + Thyroid Hormone answer

Can you take Sea Moss with Thyroid Hormone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Due to its iodine content, sea moss might alter the effects of thyroid hormone.

Full Sea Moss + Thyroid Hormone answer

Can you take Bacopa with Thyroid Hormone?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, bacopa might have additive effects when used with thyroid hormone.

Full Bacopa + Thyroid Hormone answer

Can you take Fucus Vesiculosus with Thyroid Hormone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Due to its iodine content, Fucus vesiculosus might alter the effects of thyroid hormone.

Full Fucus Vesiculosus + Thyroid Hormone answer

Can you take Lemon Balm with Thyroid Hormone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, lemon balm might interfere with thyroid hormone replacement therapy.

Full Lemon Balm + Thyroid Hormone answer

Can you take Karaya Gum with Thyroid Hormone?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Co-administration of oral drugs with bulk forming laxatives such as karaya gum may decrease, increase, or have no effect on the absorption o...

Full Karaya Gum + Thyroid Hormone answer

Can you take Marshmallow with Thyroid Hormone?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, mucilage in marshmallow might impair absorption of oral drugs.

Full Marshmallow + Thyroid Hormone answer

Can you take Xanthan Gum with Thyroid Hormone?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, xanthan gum can alter the absorption of oral drugs due to its fiber qualities.

Full Xanthan Gum + Thyroid Hormone answer

Can you take Activated Charcoal with Thyroid Hormone?

Major Use real caution — this is a major-rated interaction, generally best avoided or used only under close supervision. Activated charcoal reduces systemic exposure to many drugs, including those that undergo enterohepatic recirculation, regardless of the rout...

Full Activated Charcoal + Thyroid Hormone answer

Can you take Tiratricol with Thyroid Hormone?

Major Use real caution — this is a major-rated interaction, generally best avoided or used only under close supervision. Concomitant use of tiratricol with thyroid hormones may have additive effects.

Full Tiratricol + Thyroid Hormone answer

Can you take Acetyl-l-carnitine with Thyroid Hormone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, acetyl-L-carnitine might decrease the effectiveness of thyroid hormone replacement.

Full Acetyl-l-carnitine + Thyroid Hormone answer

Can you take Ashwagandha with Thyroid Hormone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Ashwagandha might increase the effects and adverse effects of thyroid hormone.

Full Ashwagandha + Thyroid Hormone answer

Can you take Bugleweed with Thyroid Hormone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, bugleweed may alter thyroid function.

Full Bugleweed + Thyroid Hormone answer

Can you take Coffee Charcoal with Thyroid Hormone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Coffee charcoal can reduce the absorption of orally administered drugs and should be separated from oral drug administration by at least two...

Full Coffee Charcoal + Thyroid Hormone answer

Can you take European Mandrake with Thyroid Hormone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concurrent use might increase absorption of some drugs because of inhibited gastrointestinal (GI) motility caused by European...

Full European Mandrake + Thyroid Hormone answer

Can you take Glucomannan with Thyroid Hormone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, glucomannan may decrease absorption of drugs taken orally.

Full Glucomannan + Thyroid Hormone answer

Can you take Guggul with Thyroid Hormone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, guggul might increase the risk for adverse effects when taken with thyroid hormone therapy.

Full Guggul + Thyroid Hormone answer

Can you take Niacin with Thyroid Hormone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, niacin might antagonize the therapeutic effects of thyroid hormones.

Full Niacin + Thyroid Hormone answer

Can you take Tyrosine with Thyroid Hormone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, tyrosine might have additive effects with thyroid hormone medications.

Full Tyrosine + Thyroid Hormone answer

Can you take Alpha-lipoic Acid with Thyroid Hormone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, alpha-lipoic acid might decrease the effects of thyroid hormone drugs.

Full Alpha-lipoic Acid + Thyroid Hormone answer
Read the list like a pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each entry links to a full report with the clinical detail, likelihood, evidence level, and citations for that exact combination.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

How Does Our Interaction Checker Work?

Behind every verdict on this page is a category system. Our source database doesn’t document supplement interactions drug-by-drug — it documents them against groups of medications that behave the same way (for example, “drugs processed by the CYP3A4 liver enzyme” or “blood-thinning medications”).

So the check works in three steps: (1) Thyroid Hormone is classified into the pharmacology categories it belongs to, (2) every supplement interaction documented against any of those categories is inherited by Thyroid Hormone, and (3) each ingredient keeps its own severity, likelihood, and evidence grades from the underlying record. That’s why one supplement can carry several records for one drug — it may interact through more than one category.

Thyroid Hormone sits in 2 interaction categories. Open any one to see what the group means:

Thyroid Hormone 21 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

21 of the supplement ingredients on this page reach Thyroid Hormone through this category.

Oral Drugs 17 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

17 of the supplement ingredients on this page reach Thyroid Hormone through this category.

Check a real product

Take a Supplement Product? Check the Whole Bottle Against Thyroid Hormone

Most supplements are combination products — and the interaction may come from an ingredient you didn’t buy it for. Search any product below (or scan its label) and we’ll check every ingredient on it against Thyroid Hormone.

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Pharmacist Counseling Corner

Thyroid Hormone & Supplements: Common Questions

What supplements interact with Thyroid Hormone?
Our database currently documents 38 ingredients with a known Thyroid Hormone interaction (2 major, 26 moderate, 10 minor). The practical move: scan the major group first, then look up the exact supplements you take rather than reading all 38. The highest-ranked right now: Activated Charcoal, Tiratricol, Acetyl-l-carnitine.
Which Thyroid Hormone supplement interactions are the most serious?
Focus on the major group: Activated Charcoal and Tiratricol. A major rating means the combination can be clinically significant, not that harm is guaranteed — but it's exactly the kind of thing to run past your pharmacist before your next dose, not after. Jump to the ranked list.
Can I take vitamins or supplements while on Thyroid Hormone?
Plenty of supplements coexist fine with Thyroid Hormone; a shorter list does not. Rather than memorizing it, check the specific ingredients on your labels — the ranked list above covers every one we've checked, and multi-ingredient products can be checked label-by-label with our scanner. Try the label scanner or the interaction checker.
Do brands like Etwon have the same supplement interactions as Thyroid Hormone?
Yes — Etwon all contain Thyroid Hormone, so everything on this page applies to them equally. Interactions belong to the active drug, never to the brand on the box; the same is true of generics.
Where do these interaction ratings come from?
Every rating comes from the Natural Medicines database — the same evidence-graded reference pharmacists and hospitals use — and each interaction carries three separate grades: severity (how bad it can be), likelihood (how well it's documented in studies and case reports), and an evidence level. Our pharmacists review the content; we never let an AI decide an interaction. See how to read the ratings and our editorial policy.
What about Thyroid Hormone and my other medications?
This page covers Thyroid Hormone against supplements and herbal ingredients. Checking Thyroid Hormone against your other prescription or OTC medications is a different tool — our drug interaction checker covers that side. Head to the drug–drug interaction checker.

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

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Sourcing

Where This Data Comes From — and Why You Can Trust It

🧪 Licensed clinical database

Every interaction verdict on this page comes from Natural Medicines Pro (TRC Healthcare / Therapeutic Research) — the same evidence-graded reference used by pharmacists and hospitals. We license this data directly; we do not scrape it, and no AI invents an interaction.

🧑‍⚕️ Pharmacist review

This page is curated and coded by , Clinical Pharmacist, with additional analysis by the HelloPharmacist Pharmacist Team. Editorial commentary is ours; the licensed interaction records are shown as sourced.

🔄 Kept current

Our interaction database refreshes on a weekly cycle, and this page re-checks the live database every time it’s rebuilt — what you see reflects the database as of September 24, 2026.

🔍 Full transparency

How every dataset on this site is sourced, licensed, and updated is documented publicly: our data sources · editorial policy · how we use AI.

Educational information, not medical advice. An interaction being on file does not mean it will happen to you — and absence of one is not proof of safety. Never start or stop a medication or supplement without talking to your pharmacist or doctor.