Drug & supplement interaction

Black Hoof Mushroom + Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine

Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine brand name: Colrex.

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

Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine falls into 2 drug categories that Black Hoof Mushroom can interact with; the most serious is rated moderate. Theoretically, black hoof mushroom might increase the levels and clinical effects of CYP1A2 substrates.

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

Black Hoof Mushroom and Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine

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

Why Are There 2 Interactions?

Black Hoof Mushroom interacts with whole categories of medication. Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine falls into 2 of those categories, so it can interact with Black Hoof Mushroom 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, Chlorpheniramine, Codeine, Phenylephrine

Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Black Hoof Mushroom interacts with.

Theoretically, black hoof mushroom might increase the levels and clinical effects of CYP1A2 substrates.
In vitro, polysaccharides from black hoof mushroom grown in culture inhibit CYP1A2. This effect has not been reported in humans.
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 short version on combining Black Hoof Mushroom with this cold-and-cough combo (Colrex). In lab dishes, this mushroom seems to slow down a liver enzyme called CYP1A2. If that happened in real life, drugs cleared by CYP1A2 could build up a bit and have stronger effects. For this product, that mostly matters for the chlorpheniramine piece, so you might feel more drowsiness, dry mouth, or grogginess than usual.

The reassuring part: this is only a theoretical, test-tube finding. It has not been shown to happen in people, so I wouldn't lose sleep over it. Still, since this medicine already makes many folks sleepy and contains codeine, it's worth a quick chat with your pharmacist or doctor before pairing them, especially if you take other sedating medicines.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Shon, Y. H. and Nam, K. S. Inhibition of cytochrome P450 isozymes in rat liver microsomes by polysaccharides derived from Phellinus linteus. Biotechnol Lett 2003;25(2):167-172. PubMed
Moderate

CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES

2 of 2

Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine also falls under CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES.

Theoretically, black hoof mushroom might increase the levels and clinical effects of CYP2E1 substrates.
In vitro, polysaccharides from black hoof mushroom grown in culture inhibit CYP2E1. This effect has not been reported in humans.
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

This combination product (Colrex) has several ingredients, but the one that connects to this interaction is acetaminophen, which your liver partly processes through an enzyme called CYP2E1. In lab dishes, compounds from black hoof mushroom slowed that enzyme down. In theory, that could let a bit more acetaminophen linger before it's cleared. The honest truth is that this has only been seen in test tubes, never in actual people, so the real-world risk looks small.

Here's the practical takeaway: at normal doses this likely won't cause trouble, but acetaminophen is hard on the liver in large amounts, so I wouldn't stack lots of extra acetaminophen on top. Before pairing the mushroom with Colrex, just run it by your pharmacist or doctor so they can check your full medication list.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Shon, Y. H. and Nam, K. S. Inhibition of cytochrome P450 isozymes in rat liver microsomes by polysaccharides derived from Phellinus linteus. Biotechnol Lett 2003;25(2):167-172. 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

Black Hoof Mushroom Also Interacts With Other Medications

Black Hoof Mushroom has 307 moderate known drug interactions in our database — the Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine one above is among them. If you take anything else, check it against the full list below.

Moderate 307 No known interaction 2,523 (incl. Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine)
Taking anything else?

Check Another of Your Medications Against Black Hoof Mushroom

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

Everything else you take

See Every Supplement That Interacts With Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine

This page covers Black Hoof Mushroom only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine page lists 338 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 Ephedra (major).

By severity: 18 major · 275 moderate · 45 minor.

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

“Someone taking Colrex is usually fighting a miserable cold, and cold season is also when people reach for herbal sleep aids and energy boosters, which is exactly where this list bites hardest. Colrex combines acetaminophen, chlorpheniramine, codeine, and phenylephrine, and 18 of its 338 supplement interactions rate major, enough to war…”

Reviewed by 2 · Jul 18, 2026

Open the Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine interaction page

How much people look this up

Where Black Hoof Mushroom and Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine 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 Black Hoof Mushroom
Steady interest

#1,299 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine
Top 10%

#221 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 Black Hoof Mushroom

What is Black Hoof Mushroom?

Black Hoof Mushroom
  • Immune system support
  • Antioxidant support
  • General wellness
  • Traditional cancer-supportive use
  • Inflammation

Black Hoof Mushroom (Phellinus linteus) is a medicinal mushroom long used in East Asian traditional medicine, mainly for immune support. Most of the supporting evidence comes from laboratory and animal studies, and high-quality human research is limited. Talk to your pharmacist or doctor before using it, especially if you have a health condition or take other medicines.

Read the full Black Hoof Mushroom monograph & all interactions
Keep checking

Other Drugs & Black Hoof Mushroom

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

0Major
307Moderate
0Minor
2,522No known interaction
307 Moderate 2,522 No interaction
Moderate

307 interactions

Showing 60 of 307 moderate interactions — see all 307 on the Black Hoof Mushroom page.

No interaction 2,522 drugs checked — show the list

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

Showing the 60 most looked-up of 2,522 medications checked with no known interaction — see the full Black Hoof Mushroom list.

See the full Black Hoof Mushroom interactions page
See every supplement checked against Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine, 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
Black Hoof Mushroom monograph › Uses, safety, and every drug interaction in one place Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine supplement interactions › Every supplement checked against Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine, 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 Black Hoof Mushroom and Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine Together: Common Questions

Can you take Black Hoof Mushroom with Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine?
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 Black Hoof Mushroom and Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine?
Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine belongs to more than one drug category, and Black Hoof Mushroom 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 Black Hoof Mushroom and Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine 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, Chlorpheniramine, Codeine, Phenylephrine and Black Hoof Mushroom?

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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.