Drug & supplement interaction

Soy + Fluvastatin

Fluvastatin brand names: Lescol, Lescol XL.

Minor Interaction
Medically reviewed by · Updated September 2026
The bottom line Minor

Soy has a minor interaction with Fluvastatin. Soy might modestly induce CYP2C9 enzymes.

Read the full interaction report
SeverityMinor
LikelihoodUnlikely
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Soy and Fluvastatin

Here is the interaction we found between these two, with the evidence behind it.

Minor

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

Why this applies to Fluvastatin

Fluvastatin falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES — the group Soy interacts with.

Soy might modestly induce CYP2C9 enzymes. However, this effect does not seem to be clinically significant.
In vitro research suggests that an unhydrolyzed soy extract might induce CYP2C9. However, the significance of this interaction is likely minimal. In healthy females taking a specific extract of soy (Genistein Soy Complex, Source Naturals), blood levels of losartan, a CYP2C9 substrate, were not significantly affected.
Severity Minor Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist for soy and your fluvastatin. Your liver uses an enzyme called CYP2C9 to break down fluvastatin, and lab studies hint that soy might speed that enzyme up a little. In theory, a faster breakdown could mean slightly less fluvastatin sticking around, which could nudge your cholesterol-lowering benefit down a touch. Fluvastatin is not a prodrug, so it doesn't get switched on by this enzyme.

The good news: this is very weak evidence, mostly from test-tube work, and a human study with a similar drug showed no real change. Everyday soy foods are almost certainly fine. If you take concentrated soy isoflavone supplements, just mention it to your pharmacist or doctor so they can keep an eye on your numbers.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Wang G, Xiao CQ, Li Z, et al. Effect of soy extract administration on losartan pharmacokinetics in healthy female volunteers. Ann Pharmacother 2009;43:1045-9. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction 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.
  • PossibleInteraction 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.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Soy Also Interacts With Other Medications

Soy has 9 major, 343 moderate, 258 minor known drug interactions in our database — the Fluvastatin one above is one of them. If you take anything else, check it against the full list below.

Major 9 Moderate 343 Minor 258 No known interaction 2,220 (incl. Fluvastatin)
Taking anything else?

Check Another of Your Medications Against Soy

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

Everything else you take

See Every Supplement That Interacts With Fluvastatin

This page covers Soy only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fluvastatin page lists 128 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Apple (major), Beer (major), Grapefruit (major) and Siberian Cocklebur (major).

By severity: 7 major · 97 moderate · 24 minor.

Open the Fluvastatin interaction page

One more smart check

Taking Soy as Part of a Dietary Supplement Product? Check It for Interactions

We hold 821 real supplement products containing Soy, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Soy. Your product may carry other ingredients that interact with Fluvastatin too, on top of Soy — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Soy and Fluvastatin 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 Soy
Top 25%

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

29 days ago today
Medication Fluvastatin
Top half

#986 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.

Supplement

About Soy

What is Soy?

  • Menopause symptoms (hot flashes)
  • Heart and cholesterol health
  • Bone health
  • Plant-based protein source
  • General nutrition

Soy is a nutritious bean that is a staple food and a popular source of plant protein and isoflavones. Eating soy foods as part of a balanced diet is generally considered safe for most people, and there is moderate evidence it may modestly help cholesterol and some menopause symptoms, though results vary. Talk with your pharmacist or doctor before using concentrated soy isoflavone supplements, especially if you have a history of hormone-sensitive conditions.

Read the full Soy monograph & all interactions
Medication

About Fluvastatin

What Is Fluvastatin Used For?

Brand names: Lescol, Lescol XL

Fluvastatin capsules are used alongside diet to lower total cholesterol, LDL cholesterol, triglycerides, and apolipoprotein B, and to raise HDL cholesterol in adults with primary hypercholesterolemia (high cholesterol) or mixed dyslipidemia (abnormal cholesterol and triglyceride levels). Fluvastatin capsules are also used in boys and girls aged 10–16 who have heterozygous familial hypercholesterolemia (an inherited form of high cholesterol) when diet alone has not worked. In adults with clinically evident coronary heart disease (CHD), fluvastatin capsules may reduce the risk of needing a coronary revascularization procedure (a procedure to restore blood flow, such as angioplasty) and can slow the progression of coronary atherosclerosis (plaque buildup in heart arteries).

Fluvastatin sodium extended-release tablets and Lescol XL (extended-release tablet) share similar uses: reducing LDL cholesterol in adults with primary hyperlipidemia, reducing LDL in adults and children aged 10 and older with heterozygous familial hypercholesterolemia who require the highest available dose, and reducing cardiovascular risk in adults with established coronary heart disease. Fluvastatin is always used together with a cholesterol-lowering diet, not as a replacement for one.

See full Fluvastatin drug information
Keep checking

Other Drugs & Soy

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

9Major
343Moderate
258Minor
2,219No known interaction
9 Major 343 Moderate 258 Minor 2,219 No interaction
Major

9 interactions

Moderate

343 interactions

Showing 60 of 343 moderate interactions — see all 343 on the Soy page.

Minor

258 interactions

Showing 60 of 258 minor interactions — see all 258 on the Soy page.

No interaction 2,219 drugs checked — show the list

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

Showing the 60 most looked-up of 2,219 medications checked with no known interaction — see the full Soy list.

See the full Soy interactions page
See every supplement checked against Fluvastatin, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
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Pharmacist Counseling Corner

Taking Soy and Fluvastatin Together: Common Questions

Can you take Soy with Fluvastatin?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Soy and Fluvastatin interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Fluvastatin and Soy?

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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.