Drug & supplement interaction

Coral + Levothyroxine

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

No Known Interaction
The bottom line No known interaction

We found no known interaction between Coral 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.

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Interaction report

Coral 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 Coral 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Coral at all — not against Levothyroxine, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Coral safety at a glance

Coral overall Use caution It is largely a calcium source, but quality and contamination concerns and overstated claims warrant caution.
Pregnancy Use caution Use only under medical guidance because of contamination and dosing concerns; prefer tested prenatal calcium.
Breastfeeding Use caution Safety is not well studied; choose a tested calcium product and ask your doctor.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Levothyroxine and Coral? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Coral Itself Has Been Linked To

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

  • Liver problems / A higher chance of infection Worth acting on Additional detail

    “Surgically, coral can cause infections. However, it doesn't carry the risk of transmitting infections such as HIV, hepatitis C, and Creutzfeldt-Jakob disease. The local infection rate was 4% for coral grafts as compared to the bone allograph infection rate of 20%.”

    Coral · Natural Medicines adverse-effect record, reported in hepatitis.

Everything above comes from the Natural Medicines adverse-effect record for Coral — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Levothyroxine’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Levothyroxine column appears here.

How to take them

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

At least one FDA label for a product containing Levothyroxine says to take it on an empty stomach. Most supplements — Coral 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 Coral 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 Coral 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 Coral 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 Coral 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 Coral as Part of a Dietary Supplement Product? Check It for Interactions

We hold 60 real supplement products containing Coral, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Coral. Even though Coral 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 Coral 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 Coral
Steady interest

#1,162 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 Coral reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Coral 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 Coral

What is Coral?

  • Calcium and mineral supplementation
  • Bone health support
  • Antacid / acid reduction
  • General 'alkalizing' wellness claims
  • Trace mineral source

Coral calcium is a calcium supplement made from coral skeletons (often fossilized) that also contains small amounts of other minerals. It is essentially a form of calcium carbonate, and there is no good evidence it offers special health benefits beyond ordinary, less costly calcium supplements. Talk to your pharmacist before using it, especially because of concerns about purity, lead contamination, and exaggerated marketing claims.

Calcified skeleton (coral) used as a calcium source; 'coral calcium' · Capsules, tablets, powders, chewables

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

Coral: dosing

There is no special established dose for coral calcium beyond general calcium recommendations. The right amount of calcium depends on your age, sex, diet, and health, and total intake from food plus supplements should usually stay within recommended limits to avoid excess.Follow the product label and, ideally, look for products tested for heavy metals.

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

Read the full Coral 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 & Coral

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

0Major
0Moderate
0Minor
2,829No known interaction
No interaction 2,829 drugs checked — show the list
Evidence & sources

Coral References

The 5 references that drive our Coral 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. Schulz A, Hilgers RD, Niedermeier W. The effect of splinting of teeth in combination with reconstructive periodontal surgery in humans. Clin Oral Investig 2000;4:98-105.. PubMed
  2. Vuola J, Bohling T, Kinnunen J, et al. Natural coral as bone-defect-filling material. J Biomed Mater Res 2000;51:117-22.. DOI
  3. Thalgott JS, Klezl Z, Timlin M, Giuffre JM. Anterior lumbar interbody fusion with processed sea coral (coralline hydroxyapatite) as part of a circumferential fusion. Spine 2002;27:E518-25.. PubMed
  4. Marchac D, Sandor G. Use of coral granules in the craniofacial skeleton. J Craniofac Surg 1994;5:213-7. PubMed
  5. Roux FX, Brasnu D, Menard M, et al. Madreporic coral for cranial base reconstruction. 8 years experience. Acta Neurochir (Wien) 1995;133:201-205. 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 Coral and Levothyroxine Together: Common Questions

Is it safe to take Coral with Levothyroxine?
We do not list a known interaction between Coral 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.
Should I take Coral 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 Coral 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.
Does Levothyroxine interact with any supplements?
Yes. Levothyroxine has documented interactions with 50 supplements in our database — Coral 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

Still Have a Question About Levothyroxine and Coral?

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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.