Drug & supplement interaction

Reishi Mushroom + Insulin

Insulin brand name: NovoRapid Insulin.

Moderate Interaction
The bottom line Moderate

Reishi Mushroom has a moderate interaction with Insulin. Theoretically, reishi mushroom might have additive effects with antidiabetes drugs.

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

Reishi Mushroom and Insulin

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

Moderate

ANTIDIABETES DRUGS

Why this applies to Insulin

Insulin falls under ANTIDIABETES DRUGS — the group Reishi Mushroom interacts with.

Theoretically, reishi mushroom might have additive effects with antidiabetes drugs.
Animal research suggests that reishi mushroom decreases blood sugar. However, in patients with type 2 diabetes, taking reishi mushroom does not reduce fasting glucose levels, and its effects on glycated hemoglobin are inconsistent.
Severity Moderate Likelihood Possible Evidence D

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 basic idea: insulin already lowers your blood sugar, and reishi mushroom might nudge it down a little further. If both work in the same direction at the same time, the worry is that your sugar could drop too low. With a fast-acting insulin like NovoRapid, low blood sugar can show up as shakiness, sweating, a racing heart, confusion, or feeling lightheaded.

That said, I want to keep this in perspective. The blood-sugar-lowering effect comes mostly from animal studies, and in people with type 2 diabetes reishi didn't reliably lower fasting glucose. So this is more of a theoretical caution than a proven problem. If you'd like to try reishi, check in with your pharmacist or doctor first and keep an eye on your readings.

References
  1. Seto, S. W., Lam, T. Y., Tam, H. L., Au, A. L., Chan, S. W., Wu, J. H., Yu, P. H., Leung, G. P., Ngai, S. M., Yeung, J. H., Leung, P. S., Lee, S. M., and Kwan, Y. W. Novel hypoglycemic effects of Ganoderma lucidum water-extract in obese/diabetic (+db/+db
  2. Gao, Y., Lan, J., Dai, X., Ye, J., and Zhou, S. A Phase I/II Study of Ling Zhi Mushroom Ganoderma lucidum(W.Curt: Fr.) Lloyd (Aphyllophoromycetideae) Extract in Patients with Type II Diabetes Mellitus. International Journal of Medicinal Mushrooms 2004;6. DOI
  3. Klupp NL, Chang D, Hawke F, Kiat H, Cao H, Grant SJ, Bensoussan A. Ganoderma lucidum mushroom for the treatment of cardiovascular risk factors. Cochrane Database Syst Rev. 2015 Feb 17;2:CD007259. 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

Reishi Mushroom Also Interacts With Other Medications

Reishi Mushroom has 374 moderate known drug interactions in our database — the Insulin one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Reishi Mushroom

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

Everything else you take

See Every Supplement That Interacts With Insulin

This page covers Reishi Mushroom only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Insulin 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 page

“Someone injecting insulin (NovoRapid) is often the same person browsing supplements sold for blood sugar support, which is exactly why this list warrants genuine caution. Nearly all 242 entries push glucose one way or the other, most often further down, stacking with insulin and raising the risk of hypoglycemia, meaning dangerously low…”

Reviewed by 2 · Jul 18, 2026

Open the Insulin interaction page

How much people look this up

Where Reishi Mushroom and Insulin 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 Reishi Mushroom
Top 10%

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

29 days ago today
Medication Insulin
Top 25%

#490 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 Reishi Mushroom

What is Reishi Mushroom?

Reishi Mushroom
  • Immune support
  • Fatigue and general well-being
  • Stress and sleep
  • Inflammation
  • Heart and cholesterol health

Reishi is a traditional Asian mushroom widely used to support the immune system and overall wellness. Human evidence for most of its claimed benefits is limited or low-quality, so it should not replace proven treatments. It is generally well tolerated for short-term use, but check with your pharmacist or doctor before starting, especially if you are pregnant, nursing, or take other medicines.

Read the full Reishi Mushroom monograph & all interactions
Keep checking

Other Drugs & Reishi Mushroom

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

0Major
374Moderate
0Minor
2,455No known interaction
Moderate

374 interactions

Showing 60 of 374 moderate interactions — see all 374 on the Reishi Mushroom page.

No interaction 2,455 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Reishi Mushroom and Insulin Together: Common Questions

Can you take Reishi Mushroom with Insulin?
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 Reishi Mushroom and Insulin 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

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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.