Drug & supplement interaction

Sweet Clover + 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 Sweet Clover 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

Sweet Clover 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 Sweet Clover 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.

Sweet Clover safety at a glance

Sweet Clover overall Use caution Generally used in small amounts, but its coumarin content can affect bleeding and the liver, so use cautiously.
Pregnancy Avoid Not enough safety information is available, so it is best avoided during pregnancy.
Breastfeeding Avoid Safety is unknown while breastfeeding, so it is best avoided.

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

Still wondering about combining Levothyroxine and Sweet Clover? 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. Sweet Clover has documented interactions with 2 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate) and hepatotoxic 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

Sweet Clover Does Interact With Other Medications

Sweet Clover has 480 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 480 No known interaction 2,350 (incl. Levothyroxine)
Taking anything else?

Check Another of Your Medications Against Sweet Clover

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

What to actually watch for

No Interaction Found — But Data Suggests Sweet Clover and Levothyroxine May Share a Side Effect

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.

  • Headache Additional detail

    Sweet Clover

    “Although rare, headache has been reported with oral use of sweet clover (1,2,18). Large amounts can cause stupor (18).”

    Sweet Clover · Natural Medicines adverse-effect record, reported in cluster headache.

    3 sources cited
    1. 1. Monographs on the medicinal uses of plant drugs. Exeter, UK: European Scientific Co-op Phytother, 1997.
    2. 2. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
    3. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

    Levothyroxine

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

Reported for Sweet Clover but not commonly for Levothyroxine: liver problems and bleeding or bruising.

Effects for Levothyroxine come from the ADVERSE REACTIONS section of its FDA label; effects for Sweet Clover 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.

How to take them

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

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

We hold 26 real supplement products containing Sweet Clover, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Sweet Clover. Even though Sweet Clover 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 Sweet Clover 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 Sweet Clover
Steady interest

#1,375 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 Sweet Clover reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Sweet Clover 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 Sweet Clover

What is Sweet Clover?

Sweet Clover
  • Varicose veins and poor circulation
  • Leg swelling (edema)
  • Hemorrhoids
  • Bruising and minor inflammation
  • Respiratory complaints

Sweet clover is a traditional European herb most often promoted for vein problems and leg swelling, but high-quality human evidence is limited. It contains coumarin, which can become dangerous if the plant spoils, so quality matters and you should talk to a pharmacist before using it.

Melilotus officinalis · Fabaceae · Above-ground parts (flowering tops, leaves, and stems) · Tea, dried herb, capsules, tincture, topical creams and ointments

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

Sweet Clover: dosing

There is no well-established standard dose for sweet clover. Traditional use varies widely depending on whether it is taken as a tea, tincture, or capsule, and the coumarin content of different products can differ a lot.The safest approach is to follow the directions on the product label and not exceed them.

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

Read the full Sweet Clover 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 & Sweet Clover

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

0Major
480Moderate
0Minor
2,349No known interaction
480 Moderate 2,349 No interaction
Moderate

480 interactions

Showing 60 of 480 moderate interactions — see all 480 on the Sweet Clover page.

No interaction 2,349 drugs checked — show the list

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

Showing the 60 most looked-up of 2,349 medications checked with no known interaction — see the full Sweet Clover list.

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

Sweet Clover References

The 6 references that drive our Sweet Clover 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. Monographs on the medicinal uses of plant drugs. Exeter, UK: European Scientific Co-op Phytother, 1997.
  2. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
  3. Wichtl MW. Herbal Drugs and Phytopharmaceuticals. Ed. N.M. Bisset. Stuttgart: Medpharm GmbH Scientific Publishers, 1994.
  4. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  5. Hogan RP III. Hemorrhagic diathesis caused by drinking an herbal tea. JAMA 1983;249:2679-80. DOI
  6. Tamura S, Warabi Y, Matsubara S. Severe liver dysfunction possibly caused by the combination of interferon beta-1b therapy and melilot (sweet clover) supplement. J Clin Pharm Ther 2012;37(6):724-5. 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 Sweet Clover and Levothyroxine Together: Common Questions

Is it safe to take Sweet Clover with Levothyroxine?
We do not list a known interaction between Sweet Clover 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 Sweet Clover and Levothyroxine have any of the same side effects?
Yes — our sources link each of them separately to one 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 Sweet Clover 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 Sweet Clover 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 Sweet Clover and Levothyroxine combination checked?
Interactions in our licensed database are recorded against drug classes. Levothyroxine is filed under 3 classifications, and Sweet Clover has documented interactions with 2 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 Sweet Clover interact with any other medications?
Yes. Sweet Clover has 480 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 — Sweet Clover 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

Sweet Clover 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 6 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Levothyroxine and Sweet Clover?

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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.