Drug & supplement interaction

Lentinan + Acetaminophen, Codeine

Acetaminophen, Codeine brand names: Tylenol w/ Codeine, Tylenol No.3.

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

Acetaminophen, Codeine falls into 2 drug categories that Lentinan can interact with; the most serious is rated moderate. Laboratory evidence suggests that lentinan might increase the activity of cytochrome P450 1A2 (CYP1A2).

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Lentinan and Acetaminophen, Codeine

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Lentinan interacts with whole categories of medication. Acetaminophen, Codeine falls into 2 of those categories, so it can interact with Lentinan in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

1 of 2

Why this applies to Acetaminophen, Codeine

Acetaminophen, Codeine falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Lentinan interacts with.

Laboratory evidence suggests that lentinan might increase the activity of cytochrome P450 1A2 (CYP1A2). So far, this interaction has not been reported in humans. However, watch for a decrease in the levels of drugs metabolized by CYP1A2 in patients taking lentinan.
Some drugs metabolized by CYP1A2 include amitriptyline (Elavil), haloperidol (Haldol), ondansetron (Zofran), propranolol (Inderal), theophylline (Theo-Dur, others), verapamil (Calan, Isoptin, others), and others.
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 honest picture for your Tylenol with Codeine. The concern on file is that lentinan, in lab and animal tests only, may speed up an enzyme called CYP1A2. That said, this enzyme isn't the main player for codeine. Codeine is actually a prodrug that has to be switched on by a different enzyme (CYP2D6) to give you pain relief, and the acetaminophen side is handled by yet other pathways. So this particular interaction doesn't line up neatly with either ingredient.

Bottom line: there's no human evidence this matters here, and I wouldn't lose sleep over it. Still, since lentinan products vary a lot and codeine carries its own risks, run it by your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Lin Y, Wei Y, Hu X, et al. Evaluation of lentinan effects on cytochrome P450 activity in rats by a cocktail method. Iran J Basic Med Sci. 2019;22(3):296-301.
Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

2 of 2

Acetaminophen, Codeine also falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES.

Laboratory research suggests that lentinan might increase the activity of cytochrome P450 2D6 (CYP2D6). So far, this interaction has not been reported in humans. However, watch for a decrease in the levels of drugs metabolized by CYP2D6 in patients taking lentinan.
Some drugs metabolized by CYP2D6 include tricyclic antidepressants such as imipramine (Tofranil) and amitriptyline (Elavil); antipsychotics such as haloperidol (Haldol), risperidone (Risperdal), and chlorpromazine (Thorazine); beta-blockers such as propranolol (Inderal), metoprolol (Lopressor, Toprol XL), and carvedilol (Coreg); tamoxifen (Nolvadex); and others.
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 wrinkle with this combo: the codeine part of Tylenol with Codeine is a prodrug. Your body has to convert it into morphine using a liver enzyme called CYP2D6 before you feel any real pain relief. Lab research hints that lentinan might speed that enzyme up. If that held true in people, your body could turn codeine into morphine a bit faster than usual.

What might that look like? Possibly stronger opioid effects like extra drowsiness, dizziness, constipation, or nausea, since more morphine could form. But honestly, this is only seen in test-tube and animal studies, never confirmed in humans, so I wouldn't lose sleep over it. The Tylenol (acetaminophen) part isn't affected. Just give your pharmacist a heads-up before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Lin Y, Wei Y, Hu X, et al. Evaluation of lentinan effects on cytochrome P450 activity in rats by a cocktail method. Iran J Basic Med Sci. 2019;22(3):296-301.

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

Lentinan Also Interacts With Other Medications

Lentinan has 815 moderate known drug interactions in our database — the Acetaminophen, Codeine one above is among them. If you take anything else, check it against the full list below.

Moderate 815 No known interaction 2,015 (incl. Acetaminophen, Codeine)
Taking anything else?

Check Another of Your Medications Against Lentinan

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

Everything else you take

See Every Supplement That Interacts With Acetaminophen, Codeine

This page covers Lentinan only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Codeine page lists 240 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Asarabacca (major), Beer (major) and Gamma-hydroxybutyrate (ghb) (major).

By severity: 9 major · 191 moderate · 40 minor.

From our pharmacist’s overview on the Acetaminophen, Codeine page

“People usually take Tylenol No. 3 (acetaminophen with codeine) for short-term pain, often while still drinking wine with dinner or reaching for an herbal sleep aid.”

Reviewed by 2 · Jul 18, 2026

Open the Acetaminophen, Codeine interaction page

One more smart check

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

We hold 1 real supplement products containing Lentinan, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Lentinan. Your product may carry other ingredients that interact with Acetaminophen, Codeine too, on top of Lentinan — 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 Lentinan and Acetaminophen, Codeine 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 Lentinan
Steady interest

#1,040 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Acetaminophen, Codeine
Top 10%

#240 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 Lentinan

What is Lentinan?

Lentinan
  • Immune support
  • Used alongside cancer treatment
  • Anti-inflammatory
  • General wellness/tonic
  • Antimicrobial support

Lentinan is a beta-glucan polysaccharide from shiitake mushrooms that is studied mainly as an immune-modulating add-on to cancer chemotherapy, where it is given by injection in a few countries. Evidence for oral supplements is limited, and quality varies widely between products. Talk with your pharmacist or doctor before using it, especially if you have a health condition or are pregnant or breastfeeding.

Read the full Lentinan monograph & all interactions
Keep checking

Other Drugs & Lentinan

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

0Major
815Moderate
0Minor
2,014No known interaction
815 Moderate 2,014 No interaction
Moderate

815 interactions

Showing 60 of 815 moderate interactions — see all 815 on the Lentinan page.

No interaction 2,014 drugs checked — show the list

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

Showing the 60 most looked-up of 2,014 medications checked with no known interaction — see the full Lentinan list.

See the full Lentinan interactions page
See every supplement checked against Acetaminophen, Codeine, 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
Lentinan monograph › Uses, safety, and every drug interaction in one place Acetaminophen, Codeine supplement interactions › Every supplement checked against Acetaminophen, Codeine, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Lentinan and Acetaminophen, Codeine Together: Common Questions

Can you take Lentinan with Acetaminophen, Codeine?
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.
Why are there 2 interactions listed for Lentinan and Acetaminophen, Codeine?
Acetaminophen, Codeine belongs to more than one drug category, and Lentinan interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Lentinan and Acetaminophen, Codeine 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 Acetaminophen, Codeine and Lentinan?

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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.