Drug & supplement interaction

Equol + Leflunomide

Leflunomide brand name: Arava.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Equol and Leflunomide 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 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

Equol and Leflunomide

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 Leflunomide and Equol 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.

Equol safety at a glance

Equol overall Use caution Generally well tolerated in studies, but long-term safety and effects on hormone-sensitive conditions are not well established.
Pregnancy Avoid Not enough safety data and possible hormone-like effects, so it is best avoided.
Breastfeeding Avoid There is no reliable safety information, so avoid use while breastfeeding.

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

Still wondering about combining Leflunomide and Equol? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Leflunomide

Interactions in our licensed database are recorded against drug classes, not just single drug names. Leflunomide is filed under 3 classifications — cytochrome p450 2c9 (cyp2c9) inhibitors, hepatotoxic drugs, oral drugs. Equol has documented interactions with 4 drug classes — the most serious being contraceptive drugs (moderate), estrogens (moderate) and testosterone (moderate) — and none of Leflunomide’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

Equol Does Interact With Other Medications

Equol has 58 moderate, 75 minor known drug interactions in our database — Leflunomide isn’t one of them. If you take anything else, check it against the full list below.

Moderate 58 Minor 75 No known interaction 2,697 (incl. Leflunomide)
Taking anything else?

Check Another of Your Medications Against Equol

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

What to actually watch for

No Interaction Found — But Data Suggests Equol and Leflunomide 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.

  • Bloating or gas Additional detail

    Equol

    “Orally, equol is generally well-tolerated.

    Most Common Adverse Effects:

    Orally: Abdominal distension and constipation.

    Serious Adverse Effects (Rare):

    Orally: Depression.”

    Equol · Natural Medicines adverse-effect record, reported in constipation.

    Leflunomide

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

Reported for Equol but not commonly for Leflunomide: constipation and low mood.

Effects for Leflunomide come from the ADVERSE REACTIONS section of its FDA label; effects for Equol come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 104,033 voluntary FDA FAERS reports for Leflunomide that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Everything else you take

See Every Supplement That Interacts With Leflunomide

This page covers Equol only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Leflunomide page lists 59 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Siberian Cocklebur (major), Wine (major) and Ashwagandha (moderate).

By severity: 4 major · 46 moderate · 9 minor.

From our pharmacist’s overview on the Leflunomide page

“Leflunomide (Arava) quiets rheumatoid arthritis by damping down the immune system, and its best-known danger is liver injury, so the 59 supplements and herbs on this page are worth slowing down for. Thirty-eight of them carry liver risks of their own, and of the four rated major, two are simply alcoholic drinks, while a third, Siberian…”

Reviewed by 2 · Jul 18, 2026

Open the Leflunomide interaction page

How much people look this up

Where Equol and Leflunomide 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 Equol
Top half

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

29 days ago today
Medication Leflunomide
Steady interest

#2,319 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 Equol reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Equol and Leflunomide 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 Equol

What is Equol?

  • Menopause symptoms (hot flashes)
  • Bone health support
  • Skin aging
  • Prostate health
  • General hormone balance

Equol is a compound made in the gut when some people break down soy isoflavones, and it is also sold as a supplement. Early research links it to possible benefits for menopause symptoms and bone or skin health, but the evidence is still limited and far from proven. Talk with your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Not a plant part; a metabolite produced by gut bacteria from soy isoflavones (daidzein) · Capsules, tablets, and as a component of fermented soy or red clover supplements

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

Equol: dosing

There is no official or standardized dose of equol. Amounts used in research have varied, and supplement products differ in how much they contain.The best approach is to follow the directions on the product label and not take more than recommended.

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

Read the full Equol monograph & all interactions
Medication

About Leflunomide

What Is Leflunomide Used For?

Brand name: Arava

Leflunomide tablets — sold under the brand name Arava and as generic leflunomide — are used to treat active rheumatoid arthritis (RA) in adults. Both Arava and generic leflunomide tablets are FDA-approved for this use.

Rheumatoid arthritis is an autoimmune condition in which the immune system attacks the joints, causing pain, swelling, and stiffness. Leflunomide helps calm that overactive immune response to reduce symptoms and slow joint damage.

Most-Reported Side Effects for Leflunomide

From FAERS, the FDA’s public side-effect reporting system (104,033 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Rheumatoid arthritis 25,337 reports
Arthralgia 17,395 reports
Drug intolerance 15,935 reports
Joint swelling 15,925 reports
Fatigue 15,756 reports
See full Leflunomide drug information
Keep checking

Other Drugs & Equol

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

0Major
58Moderate
75Minor
2,696No known interaction
58 Moderate 75 Minor 2,696 No interaction
Moderate

58 interactions

Minor

75 interactions

Showing 60 of 75 minor interactions — see all 75 on the Equol page.

No interaction 2,696 drugs checked — show the list

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

Showing the 60 most looked-up of 2,696 medications checked with no known interaction — see the full Equol list.

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

Equol References

The 7 references that drive our Equol 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. Aso T. Equol improves menopausal symptoms in Japanese women. J Nutr 2010;140:1386S-9S. PubMed
  2. Jenks BH, Iwashita S, Nakagawa Y, et al. A pilot study on the effects of S-equol compared to soy isoflavones on menopausal hot flash frequency. J Womens Health (Larchmt) 2012;21:674-82.
  3. Oyama A, Ueno T, Uchiyama S, et al. The effects of natural S-equol supplementation on skin aging in postmenopausal women: a pilot randomized placebo-controlled trial. Menopause 2012;19:202-10. PubMed
  4. Gimenez I, Lou M, Vargas F, et al. Renal and vascular actions of equol in the rat. J Hypertens 1997;15:1303-8. PubMed
  5. Martin ME, Haouriqui M, Pelissero C, et al. Interactions between phytoestrogens and human sex steroid binding protein. Life Sci 1996;58:429-36. PubMed
  6. Martinez RM, Gimenez I, Lou JM, et al. Soy isoflavonoids exhibit in vitro biological activities of loop diuretics. Am J Clin Nutr 1998;68:1354S-57S. PubMed
  7. Alda JO, Mayoral JA, Lou M, et al. Purification and chemical characterization of a potent inhibitor of the Na-K-Cl cotransport system in rat urine. Biochem Biophys Res Commun 1996;221:279-85. 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 Equol and Leflunomide Together: Common Questions

Is it safe to take Equol with Leflunomide?
We do not list a known interaction between Equol and Leflunomide. 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 Equol and Leflunomide 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.
How was the Equol and Leflunomide combination checked?
Interactions in our licensed database are recorded against drug classes. Leflunomide is filed under 3 classifications, and Equol has documented interactions with 4 drug classes — none of Leflunomide'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 Equol interact with any other medications?
Yes. Equol has 133 documented drug interactions in our database — Leflunomide 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 Leflunomide interact with any supplements?
Yes. Leflunomide has documented interactions with 59 supplements in our database — Equol is not one of them. The Leflunomide 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

Equol monograph Uses, safety profile, and every drug interaction in one place Leflunomide drug information The full plain-English guide to this medication Leflunomide supplement interactions Every supplement checked against Leflunomide, 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 7 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Leflunomide and Equol?

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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.