Drug & supplement interaction

Poria Mushroom + Promethazine

Promethazine brand name: Phenergan.

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

Poria Mushroom has a moderate interaction with Promethazine. Theoretically, poria mushroom might decrease the clinical effects of anticholinergic drugs.

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

Poria Mushroom and Promethazine

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

Moderate

ANTICHOLINERGIC DRUGS

Why this applies to Promethazine

Promethazine falls under ANTICHOLINERGIC DRUGS — the group Poria Mushroom interacts with.

Theoretically, poria mushroom might decrease the clinical effects of anticholinergic drugs.
In animal research, poria mushroom essential oil reduces acetylcholinesterase activity. This interaction has not been shown 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 gist: Promethazine (Phenergan) works partly by blocking acetylcholine, the same chemistry behind its drying, calming, and anti-nausea effects. In animal studies, poria mushroom appears to raise available acetylcholine by slowing the enzyme that breaks it down. In theory, that could push back against promethazine and make it work a little less well, so you might notice slightly less relief from nausea or allergy symptoms.

I want to be honest with you though: this is purely theoretical from animal research and has never been shown in people. Promethazine is not a prodrug, so it doesn't get flipped around here. For most folks this is a low concern. Still, if you're starting poria and you notice your promethazine isn't doing its job, mention it to your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Lv Q, Di X, Bian B, Li K, Guo J. Neuroprotective effects of Poria cocos (Agaricomycetes) essential oil on Aß1-40-induced learning and memory deficit in rats. Int J Med Mushrooms 2022;24(10):73-82.

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

Poria Mushroom Also Interacts With Other Medications

Poria Mushroom has 416 moderate known drug interactions in our database — the Promethazine one above is one of them. If you take anything else, check it against the full list below.

Moderate 416 No known interaction 2,414 (incl. Promethazine)
Taking anything else?

Check Another of Your Medications Against Poria Mushroom

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

From our Q&A

Questions About Poria Mushroom or Promethazine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Poria Mushroom or Promethazine, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Promethazine

This page covers Poria Mushroom only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Promethazine page lists 83 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Henbane (major), Scopolia (major), Alfalfa (moderate) and Angel's Trumpet (moderate).

By severity: 3 major · 57 moderate · 23 minor.

From our pharmacist’s overview on the Promethazine page

“Promethazine (Phenergan) is a phenothiazine antihistamine used for allergies, nausea, and motion sickness, and it is strongly anticholinergic on its own, causing dry mouth, blurred vision, drowsiness, and constipation. That is why the 83 supplements and herbs on this list deserve real attention, starting with the three rated major.”

Reviewed by 2 · Jul 18, 2026

Open the Promethazine interaction page

One more smart check

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

We hold 1,303 real supplement products containing Poria Mushroom, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Poria Mushroom. Your product may carry other ingredients that interact with Promethazine too, on top of Poria Mushroom — 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 Poria Mushroom and Promethazine 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 Poria Mushroom
Top 25%

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

29 days ago today
Medication Promethazine
Steady interest

#1,432 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 Poria Mushroom

What is Poria Mushroom?

  • Fluid retention and swelling
  • Digestive complaints
  • Sleep and calming support
  • General wellness and immune support
  • Urinary support

Poria mushroom (Fu Ling) is a fungus long used in Traditional Chinese Medicine, mainly as a mild diuretic and digestive and calming aid. Modern scientific evidence in humans is very limited, so its benefits are not well proven. It is generally considered well tolerated, but talk with your pharmacist or doctor before using it, and avoid it in pregnancy and breastfeeding due to a lack of safety data.

Read the full Poria Mushroom monograph & all interactions
Medication

About Promethazine

What Is Promethazine Used For?

Brand name: Phenergan

Promethazine treats a range of allergy problems. It also helps with motion sickness, nausea and vomiting after anesthesia or surgery, and sedation before or after surgery or during labor.

Not every form has the same uses. The oral tablets, oral solution and rectal suppositories are labeled for ongoing allergy conditions such as allergic rhinitis and hives. The injection is labeled for allergic reactions when oral therapy is impossible or contraindicated, and it also has surgery-related uses.

See full Promethazine drug information
Keep checking

Other Drugs & Poria Mushroom

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

0Major
416Moderate
0Minor
2,413No known interaction
416 Moderate 2,413 No interaction
Moderate

416 interactions

Showing 60 of 416 moderate interactions — see all 416 on the Poria Mushroom page.

No interaction 2,413 drugs checked — show the list

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

Showing the 60 most looked-up of 2,413 medications checked with no known interaction — see the full Poria Mushroom list.

See the full Poria Mushroom interactions page
See every supplement checked against Promethazine, 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
Poria Mushroom monograph › Uses, safety, and every drug interaction in one place Promethazine supplement interactions › Every supplement checked against Promethazine, ranked by severity Promethazine 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 Poria Mushroom and Promethazine Together: Common Questions

Can you take Poria Mushroom with Promethazine?
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 Poria Mushroom and Promethazine 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 Promethazine and Poria 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.