Drug & supplement interaction

Equol + Cefdinir

Cefdinir brand name: Omnicef.

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 Cefdinir 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 Cefdinir

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 Cefdinir 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 Cefdinir and Equol? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Cefdinir

Interactions in our licensed database are recorded against drug classes, not just single drug names. Cefdinir is filed under 6 classifications — including organic anion transporter 3 (oat3) substrates, organic anion transporter 1 (oat1) substrates, antibiotic drugs. Equol has documented interactions with 4 drug classes — the most serious being contraceptive drugs (moderate), estrogens (moderate) and testosterone (moderate) — and none of Cefdinir’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 — Cefdinir 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. Cefdinir)
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 Cefdinir 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.

  • 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.

    Cefdinir

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

  • Constipation Additional detail

    Equol

    “Orally, equol has been reported to cause abdominal distention and constipation.”

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

    1 source cited
    1. 19075. 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.

    Cefdinir

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

Reported for Equol but not commonly for Cefdinir: low mood.

Effects for Cefdinir 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 7,629 voluntary FDA FAERS reports for Cefdinir 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.

From our Q&A

Questions About Equol or Cefdinir

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Equol or Cefdinir, 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 Cefdinir

This page covers Equol only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Cefdinir page lists 60 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Siberian Cocklebur (major), African Wild Potato (moderate) and Aristolochia (moderate).

By severity: 3 major · 46 moderate · 11 minor.

From our pharmacist’s overview on the Cefdinir page

“Cefdinir (Omnicef) is a short-course antibiotic for ear, sinus, throat, and skin infections, and three of its 60 supplement interactions on file are rated major and deserve genuine care. Two herbs, Siberian cocklebur and asarabacca, can damage the kidneys, an added strain nobody needs while fighting an infection.”

Reviewed by 2 · Jul 18, 2026

Open the Cefdinir interaction page

How much people look this up

Where Equol and Cefdinir 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
Steady interest

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

29 days ago today
Medication Cefdinir
Steady interest

#2,025 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 Cefdinir 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 Cefdinir

What Is Cefdinir Used For?

Brand name: Omnicef

Cefdinir treats mild to moderate bacterial infections in adults, adolescents, and children caused by susceptible bacteria. It is used for community-acquired pneumonia, acute exacerbations of chronic bronchitis, acute maxillary sinusitis (sinus infection), pharyngitis/tonsillitis (strep throat), and uncomplicated skin and skin structure infections.

In pediatric patients (ages 6 months through 12 years), cefdinir is also used to treat acute bacterial otitis media (middle ear infection). It should only be used for infections that are proven or strongly suspected to be caused by bacteria — not for viral illnesses like the common cold.

Most-Reported Side Effects for Cefdinir

From FAERS, the FDA’s public side-effect reporting system (7,629 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Diarrhea 530 reports
Chronic kidney disease 485 reports
Pneumonia 482 reports
Fatigue 462 reports
Nausea 400 reports
See full Cefdinir 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 Cefdinir, 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 Cefdinir Together: Common Questions

Is it safe to take Equol with Cefdinir?
We do not list a known interaction between Equol and Cefdinir. 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 Cefdinir have any of the same side effects?
Yes — our sources link each of them separately to 2 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 Cefdinir combination checked?
Interactions in our licensed database are recorded against drug classes. Cefdinir is filed under 6 classifications, and Equol has documented interactions with 4 drug classes — none of Cefdinir'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 — Cefdinir 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 Cefdinir interact with any supplements?
Yes. Cefdinir has documented interactions with 60 supplements in our database — Equol is not one of them. The Cefdinir 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 Cefdinir drug information The full plain-English guide to this medication Cefdinir supplement interactions Every supplement checked against Cefdinir, 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 Cefdinir 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.