Drug & supplement interaction

Soy + Insulin determir

Insulin determir brand name: Levemir.

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

Soy has a moderate interaction with Insulin determir. Soy can lower blood glucose and have additive effects with antidiabetes drugs.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceA
What do Severity, Likelihood & Evidence mean?
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Interaction report

Soy and Insulin determir

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

Moderate

ANTIDIABETES DRUGS

Why this applies to Insulin determir

Insulin determir falls under ANTIDIABETES DRUGS — the group Soy interacts with.

Soy can lower blood glucose and have additive effects with antidiabetes drugs.
Clinical research shows that whole soy diets and soy-based meals reduce fasting glucose levels in diabetic and non-diabetic individuals. Also, individuals following a soy-based meal replacement plan seem to require lower doses of sulfonylureas and metformin to manage blood glucose levels when compared with individuals following a diet plan recommended by the American Diabetes Association.
Severity Moderate Likelihood Possible Evidence A

Interaction 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.

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

Here's the simple version: soy itself can gently lower your blood sugar. Since Levemir (insulin detemir) is already working to bring your sugar down, eating a lot of soy or taking concentrated soy supplements could add to that effect. The concern isn't that soy makes the insulin dangerous, it's that the two together might push your blood sugar too low.

That could mean more episodes of hypoglycemia, things like shakiness, sweating, dizziness, a racing heart, or feeling confused. Regular soy foods in a normal diet usually aren't a big deal, but if you start a soy-heavy meal plan or add soy isoflavone capsules, that's worth a heads-up. Keep checking your sugars, watch for low readings, and talk with your pharmacist or doctor before changing your insulin dose.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Li, Z., Hong, K., Saltsman, P., DeShields, S., Bellman, M., Thames, G., Liu, Y., Wang, H. J., Elashoff, R., and Heber, D. Long-term efficacy of soy-based meal replacements vs an individualized diet plan in obese type II DM patients: relative effects on w
  2. Post-Skagegard, M., Vessby, B., and Karlstrom, B. Glucose and insulin responses in healthy women after intake of composite meals containing cod-, milk-, and soy protein. Eur J Clin Nutr 2006;60(8):949-954. PubMed
  3. Azadbakht, L., Kimiagar, M., Mehrabi, Y., Esmaillzadeh, A., Padyab, M., Hu, F. B., and Willett, W. C. Soy inclusion in the diet improves features of the metabolic syndrome: a randomized crossover study in postmenopausal women. Am J Clin Nutr 2007;85(3):7 PubMed
  4. Liu, Z. M., Chen, Y. M., and Ho, S. C. Effects of soy intake on glycemic control: a meta-analysis of randomized controlled trials. Am.J.Clin.Nutr. 2011;93(5):1092-1101. PubMed
  5. Zhang XM, Zhang YB, Chi MH. Soy protein supplementation reduces clinical indices in type 2 diabetes and metabolic syndrome. Yonsei Med J. 2016;57(3):681-9. 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, 342 moderate, 259 minor known drug interactions in our database — the Insulin determir one above is one of them. If you take anything else, check it against the full list below.

Major 9 Moderate 342 Minor 259 No known interaction 2,220 (incl. Insulin determir)
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 Insulin determir

This page covers Soy only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Insulin determir page lists 242 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Chelation Therapy Products (major), Siberian Cocklebur (major), Acai (moderate), African Wild Potato (moderate) and Agaricus Mushroom (moderate).

By severity: 2 major · 211 moderate · 29 minor.

From our pharmacist’s overview on the Insulin determir page

“Anyone using insulin detemir (Levemir) should treat this list with real caution, because nearly every one of the 242 ingredients on it acts on blood sugar, and most stack extra glucose-lowering on top of the insulin you already inject. Only two carry a major rating, but both deserve understanding first: Siberian cocklebur, which has ca…”

Reviewed by 2 · Jul 18, 2026

Open the Insulin determir 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 Insulin determir 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 Insulin determir 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 Insulin determir
Steady interest

#2,075 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 Insulin Detemir (rDNA Origin) Injection

What Is Insulin Detemir (rDNA Origin) Injection Used For?

Brand name: Levemir

Levemir (insulin detemir) is used to improve blood sugar (glucose) control in adults and children with type 1 diabetes or type 2 diabetes. It is a basal insulin, meaning it works around the clock to keep background blood sugar levels steady.

Levemir is not recommended for treating diabetic ketoacidosis (a dangerous buildup of acids in the blood that requires a different type of insulin).

See full Insulin Detemir (rDNA Origin) Injection 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
342Moderate
259Minor
2,219No known interaction
9 Major 342 Moderate 259 Minor 2,219 No interaction
Major

9 interactions

Moderate

342 interactions

Showing 60 of 342 moderate interactions — see all 342 on the Soy page.

Minor

259 interactions

Showing 60 of 259 minor interactions — see all 259 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 Insulin determir, 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
Soy monograph › Uses, safety, and every drug interaction in one place Insulin determir supplement interactions › Every supplement checked against Insulin determir, ranked by severity Insulin Detemir (rDNA Origin) Injection drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Soy and Insulin determir Together: Common Questions

Can you take Soy with Insulin determir?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Soy and Insulin determir interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Insulin determir 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.