Drug & supplement interaction

Soy + Belzutifan

Belzutifan brand name: Welireg.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Soy and Belzutifan 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

Soy and Belzutifan

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 Belzutifan and Soy 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.

Soy safety at a glance

Soy overall Use caution Soy foods are generally safe for most people, but concentrated isoflavone supplements deserve more caution.
Pregnancy Likely Safe When used orally in amounts commonly found in foods. Read the full pregnancy detail
Breastfeeding Likely Safe When used orally in amounts commonly found in foods. A single 20-gram dose of roasted soybeans, containing 37 mg isoflavones, produces four to six times less is... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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

Why No Interaction Is Listed for Belzutifan

Interactions in our licensed database are recorded against drug classes, not just single drug names. Belzutifan is filed under 3 classifications — cytochrome p450 2c19 (cyp2c19) substrates, glucuronidated drugs, oral drugs. Soy has documented interactions with 12 drug classes — the most serious being monoamine oxidase inhibitors (maois) (major), antidiabetes drugs (moderate) and antihypertensive drugs (moderate) — and none of Belzutifan’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

Soy Does Interact With Other Medications

Soy has 9 major, 343 moderate, 259 minor known drug interactions in our database — Belzutifan isn’t one of them. If you take anything else, check it against the full list below.

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.

What to actually watch for

No Interaction Found — But Data Suggests Soy and Belzutifan 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. One of them is worth acting on rather than waiting out — marked below.

  • A severe allergic reaction Worth acting on Additional detail

    Soy

    “Orally, soy can cause allergic reactions such as skin rash and itching in some people. In an 11-year-old female, allergy to soy protein resulting in a delayed itching papular rash was thought to be responsible for the reaction to injected benzathine benzylpenicillin containing possible soy protein-contaminated soy lecithin.

    Topically, soy-based ingredients were responsible for the development of hand atopic dermatiti…”

    Soy · Natural Medicines adverse-effect record, reported in allergic rhinitis (hay fever).

    3 sources cited
    1. 6412. Teixeira SR, Potter SM, Weigel R, et al. Effects of feeding 4 levels of soy protein for 3 and 6 wk on blood lipids and apolipoproteins in moderately hypercholesterolemic men. Am J Clin Nutr 2000;71:1077-84. PubMed
    2. 96422. Barni S, Mori F, Pantano S, Novembre E. Adverse reaction to benzathine benzylpenicillin due to soy allergy: a case report. J Med Case Rep. 2015;9:134. PubMed
    3. 96000. Yagami A, Suzuki K, Nakamura M, et al. Case of anaphylactic reaction to soy following percutaneous sensitization by soy-based ingredients in cosmetic products. J Dermatol. 2015;42(9):917-8. PubMed

    Belzutifan

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

  • A stuffy or runny nose Additional detail

    Soy

    “Inhaled soy dust and soy hull aeroallergen can trigger symptoms of asthma and allergic rhinitis.”

    Soy · Natural Medicines adverse-effect record, reported in allergic rhinitis (hay fever).

    3 sources cited
    1. 5084. Codina R, Ardusso L, Lockey RF, et al. Sensitization to soybean hull allergens in subjects exposed to different levels of soybean dust inhalation in Argentina. J Allergy Clin Immunol 2000;105:570-6. PubMed
    2. 5085. Anto JM, Sunyer J, Rodriguez-Roisin R, et al. Community outbreaks of asthma associated with inhalation of soybean dust. Toxicoepidemiological Committee. N Engl J Med 1989;320:1097-1102. PubMed
    3. 5086. White MC, Etzel RA, Olson DR, Goldstein IF. Re-examination of epidemic asthma in New Orleans, Louisianna, in relation to the presence of soy at the harbor. Am J Epidemiol 1997;145:432-8.

    Belzutifan

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

  • Constipation Additional detail

    Soy

    “In the 1950s and 1960s, cases of altered thyroid function, particularly goiter, were reported in children taking soy formula. However, adding iodine to soy formula or replacing soy flour in formula with soy protein isolate has nearly eliminated the risk of altered thyroid function in most infants.

    In adults, there is some evidence that soy intake can alter thyroid function.”

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

    6 sources cited
    1. 75353. Rozman, K. K., Bhatia, J., Calafat, A. M., Chambers, C., Culty, M., Etzel, R. A., Flaws, J. A., Hansen, D. K., Hoyer, P. B., Jeffery, E. H., Kesner, J. S., Marty, S., Thomas, J. A., and Umbach, D. NTP-CERHR expert panel report on the reproductive and dev
    2. 75651. Van Wyk JJ, Arnold MB, Wynn J, and et al. The effects of a soybean product on thyroid function in humans. Pediatrics 1959;24:752-760. DOI
    3. 75206. Fitzpatrick, M. Soy formulas and the effects of isoflavones on the thyroid. N.Z.Med J 2-11-2000;113(1103):24-26.
    4. 7806. Persky VW, Turyk ME, Wang L, et al. Effect of soy protein on endogenous hormones in postmenopausal women. Am J Clin Nutr 2002;75:145-53. PubMed
    5. 6466. Divi RL, Chang HC, Doerge DR. Anti-thyroid isoflavones from soybean: isolation, characterization, and mechanisms of action. Biochem Pharmacol 1997;54:1087-96. PubMed
    6. 75311. Messina, M. and Redmond, G. Effects of soy protein and soybean isoflavones on thyroid function in healthy adults and hypothyroid patients: a review of the relevant literature. Thyroid 2006;16(3):249-258. PubMed

    Belzutifan

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

  • Tiredness Additional detail

    Soy

    Recorded for Soy in the same Natural Medicines adverse-effect record shown under Constipation above.

    Belzutifan

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

  • Diarrhea / Nausea Additional detail

    Soy

    “Gastrointestinal upset, such as constipation, diarrhea, bloating, and nausea are the most common side effects of soy. Reports of "bad taste" and taste intolerance have also been documented in clinical research. Firmer stools, diarrhea, colitis, and intestinal mucosal damage has been reported in infants fed soy protein formula.”

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

    6 sources cited
    1. 2297. Albertazzi P, Pansini F, Bonaccorsi G, et al. The effect of dietary soy supplementation on hot flushes. Obstet Gynecol 1998;91:6-11. PubMed
    2. 11033. Kumar NB, Cantor A, Allen K et al. The specific role of isoflavones in reducing prostate cancer risk. Prostate 2004;59:141-7. PubMed
    3. 11082. Chen YM, Ho SC, Lam SS, et al. Soy isoflavones have a favorable effect on bone loss in Chinese postmenopausal women with lower bone mass: a double-blind, randomized, controlled trial. J Clin Endocrinol Metab 2003;88:4740-7. PubMed
    4. 15851. Krebs EE, Ensrud KE, MacDonald R, Wilt TJ. Phytoestrogens for treatment of menopausal symptoms: a systematic review. Obstet Gynecol 2004;104:824-36. PubMed
    5. 75491. Clement, Y. N., Onakpoya, I., Hung, S. K., and Ernst, E. Effects of herbal and dietary supplements on cognition in menopause: a systematic review. Maturitas 2011;68(3):256-263. PubMed
    6. 95999. Wu AH, Spicer D, Garcia A, et al. Double-blind randomized 12-month soy intervention had no effects on breast MRI fibroglandular tissue density or mammographic density. Cancer Prev Res (Phila). 2015;8(10):942-51. PubMed

    Belzutifan

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

  • A skin rash Additional detail

    Soy

    Recorded for Soy in the same Natural Medicines adverse-effect record shown under A severe allergic reaction above.

    Belzutifan

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

Reported for Soy but not commonly for Belzutifan: stomach upset, a change in thyroid levels, memory problems and an allergic reaction.

Effects for Belzutifan come from the ADVERSE REACTIONS section of its FDA label; effects for Soy 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.

Special populations

Soy in Pregnancy & Breastfeeding

Pregnancy Likely Safe

When used orally in amounts commonly found in foods.

Pregnancy Possibly Unsafe

When used orally in medicinal amounts. Soy contains mildly estrogenic constituents. Theoretically, therapeutic use of soy might adversely affect fetal development; avoid using.

Lactation Likely Safe

When used orally in amounts commonly found in foods. A single 20-gram dose of roasted soybeans, containing 37 mg isoflavones, produces four to six times less isoflavones in breast milk than provided in a soy-based infant formula. There is insufficient reliable information available about the safety of long-term use of therapeutic amounts of soy during lactation.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

Everything else you take

See Every Supplement That Interacts With Belzutifan

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

The most serious there right now: Activated Charcoal (major), Adrafinil (moderate), Artichoke (moderate), Bacopa (moderate) and Baikal Skullcap (moderate).

By severity: 1 major · 45 moderate · 14 minor.

From our pharmacist’s overview on the Belzutifan page

“A drug like belzutifan (Welireg), taken long term to keep kidney and other tumors in check, only works if a steady amount reaches the blood, so I would be genuinely careful before adding supplements here. Most of the interactions on file shift how the liver clears the drug, through the CYP2C19 enzyme or the glucuronidation pathway, nud…”

Reviewed by 2 · Jul 18, 2026

Open the Belzutifan 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. Even though Soy itself has no known interaction with Belzutifan, 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 Soy and Belzutifan 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%

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

29 days ago today
Medication Belzutifan
Steady interest

#2,243 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 Soy reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Soy and Belzutifan records this page draws on were last updated July 11, 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 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.

Glycine max · Fabaceae · Bean (seed) · Whole soybeans, soy milk, tofu, tempeh, edamame, soy protein powder, isoflavone capsules, soy lecithin

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

Soy: dosing

There is no single official dose of soy for any health condition. Amounts used in studies vary widely, and a standardized supplement dose has not been firmly established.As a food, soy is simply part of a normal diet. For supplements such as isoflavone capsules or soy protein powder, follow the directions on the product label.

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

Read the full Soy monograph & all interactions
Medication

About Belzutifan

What Is Belzutifan Used For?

Brand name: Welireg

Welireg treats several serious conditions. In adults with von Hippel-Lindau (VHL) disease, it targets associated kidney cancer (renal cell carcinoma), brain or spinal tumors (CNS hemangioblastomas), and pancreatic neuroendocrine tumors that don't need immediate surgery. It is also used in adults with clear cell renal cell carcinoma (ccRCC) — either after surgery to lower the risk of the cancer coming back (used with pembrolizumab or pembrolizumab and berahyaluronidase alfa-pmph), or as a single agent for advanced ccRCC that has already been treated with two other types of cancer drugs.

Welireg also treats pheochromocytoma or paraganglioma (PPGL) — rare tumors of the adrenal gland or nearby nerve tissue — in adults and in children 12 years and older when the tumor cannot be removed by surgery or has spread.

See full Belzutifan 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
259Minor
2,218No known interaction
Major

9 interactions

Moderate

343 interactions

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

Minor

259 interactions

Showing 60 of 259 minor interactions — see all 259 on the Soy page.

No interaction 2,218 drugs checked — show the list
Evidence & sources

Soy References

The 88 references that drive our Soy 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. Franke AA, Custer LJ, Tanaka Y. Isoflavones in human breast milk and other biological fluids. Am J Clin Nutr 1998;68:1466-73. PubMed
  2. Albertazzi P, Pansini F, Bonaccorsi G, et al. The effect of dietary soy supplementation on hot flushes. Obstet Gynecol 1998;91:6-11. PubMed
  3. Lu LJ, Anderson KE, Grady JJ, et al. Decreased ovarian hormones during a soya diet: implications for breast cancer prevention. Cancer Res 2000;60:4112-21.
  4. Pino AM, Valladares LE, Palma MA, et al. Dietary isoflavones affect sex hormone-binding globulin levels in postmenopausal women. J Clin Endocrinol Metab 2000;85:2797-800. DOI
  5. Nisley N, Klepser T. Phytoestrogens for the prevention and treatment of osteoporosis. Alt Med Alert 1999 Dec;138-42.
  6. McMichael-Phillips DF, Harding C, Morton M, et al. Effects of soy-protein supplementation on epithelial proliferation in the histologically normal human breast. Am J Clin Nutr 1998;68:1431S-5S. PubMed
  7. Petrakis NL, Barnes S, King EB, et al. Stimulatory influence of soy protein isolate on breast secretion in pre- and postmenopausal women. Cancer Epidemiol Biomarkers Prev 1996;5:785-94.
  8. Baird DD, Umbach DM, Lansdell L, et al. Dietary intervention study to assess estrogenicity of dietary soy among postmenopausal women. J Clin Endocrinol Metab 1995;80:1685-90. DOI
  9. Duncan AM, Underhill KE, Xu X, et al. Modest hormonal effects of soy isoflavones in postmenopausal women. J Clin Endocrinol Metab 1999;84:3479-84. PubMed
  10. Ginsburg J, Prelevic GM. Lack of significant hormonal effects and controlled trials of phyto-oestrogens. Lancet 2000;355:163-4. PubMed
  11. Anthony MS. Soy and cardiovascular disease: Cholesterol lowering and beyond. J Nutr 2000;130:662S-3S. PubMed
  12. Hargreaves DF, Potten CS, Harding C, et al. Two-week dietary soy supplementation has an estrogenic effect on normal premenopausal breast. J Clin Endocrinol Metab 1999;84:4017-24. DOI
  13. Lamartiniere CA. Protection against breast cancer with genistein: a component of soy. Am J Clin Nutr 2000;71:1705S-7S. PubMed
  14. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
  15. Codina R, Ardusso L, Lockey RF, et al. Sensitization to soybean hull allergens in subjects exposed to different levels of soybean dust inhalation in Argentina. J Allergy Clin Immunol 2000;105:570-6. 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 Soy and Belzutifan Together: Common Questions

Is it safe to take Soy with Belzutifan?
We do not list a known interaction between Soy and Belzutifan. 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 Soy and Belzutifan have any of the same side effects?
Yes — our sources link each of them separately to 7 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 Soy and Belzutifan combination checked?
Interactions in our licensed database are recorded against drug classes. Belzutifan is filed under 3 classifications, and Soy has documented interactions with 12 drug classes — none of Belzutifan'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 Soy interact with any other medications?
Yes. Soy has 611 documented drug interactions in our database — Belzutifan 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 Belzutifan interact with any supplements?
Yes. Belzutifan has documented interactions with 60 supplements in our database — Soy is not one of them. The Belzutifan 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 Belzutifan 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.