Drug & supplement interaction

English Ivy + Codeine Phosphate

Codeine Phosphate brand name: Codeine.

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

English Ivy has a moderate interaction with Codeine Phosphate. Theoretically, English ivy might increase the levels of drugs metabolized by CYP2D6.

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

English Ivy and Codeine Phosphate

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

Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

Why this applies to Codeine Phosphate

Codeine Phosphate falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES — the group English Ivy interacts with.

Theoretically, English ivy might increase the levels of drugs metabolized by CYP2D6.
In vitro research shows that English ivy inhibits CYP2D6 enzymes. So far, this interaction 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 twist with codeine: it's actually a prodrug. Your body has to switch it on using an enzyme called CYP2D6, which turns codeine into morphine, the part that actually relieves pain and quiets a cough. English ivy may gently block that same enzyme, at least in lab studies.

So if anything, English ivy could mean less of your codeine gets activated, which might make it work less well for pain or coughing. The good news is this is only theoretical right now, based on test-tube research, and it hasn't been seen in real people. For most folks using ivy cough syrup briefly, it's unlikely to be a big deal. Still, if your codeine seems weaker than usual, mention it to your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Rehman SU, Kim IS, Choi MS, Kim SH, Zhang Y, Yoo HH. Time-dependent Inhibition of CYP2C8 and CYP2C19 by Hedera helix Extracts, A Traditional Respiratory Herbal Medicine. Molecules. 2017;22(7). 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

English Ivy Also Interacts With Other Medications

English Ivy has 279 moderate known drug interactions in our database — the Codeine Phosphate one above is one of them. If you take anything else, check it against the full list below.

Moderate 279 No known interaction 2,551 (incl. Codeine Phosphate)
Taking anything else?

Check Another of Your Medications Against English Ivy

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

From our Q&A

Questions About English Ivy or Codeine Phosphate

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers English Ivy or Codeine Phosphate, 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 Codeine Phosphate

This page covers English Ivy only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Codeine Phosphate page lists 144 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), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Kava (major).

By severity: 7 major · 114 moderate · 23 minor.

From our pharmacist’s overview on the Codeine Phosphate page

“Codeine phosphate is an opioid painkiller and cough suppressant that slows breathing along with brain activity, and the wrong supplement can push that effect into dangerous territory. Seven of the 144 documented ingredients rate major, and nearly all of that serious risk comes from things that deepen sedation.”

Reviewed by 2 · Jul 18, 2026

Open the Codeine Phosphate interaction page

One more smart check

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

We hold 118 real supplement products containing English Ivy, each one broken down to its full ingredient list — and combination products often carry several ingredients besides English Ivy. Your product may carry other ingredients that interact with Codeine Phosphate too, on top of English Ivy — 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 English Ivy and Codeine Phosphate 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 English Ivy
Steady interest

#1,077 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Codeine Phosphate
Top 25%

#412 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 English Ivy

What is English Ivy?

English Ivy
  • Cough and chest congestion
  • Bronchitis
  • Asthma symptoms
  • Sore throat
  • Skin irritation

English ivy leaf extract is most commonly used in cough and cold syrups to help loosen mucus and ease coughing, and it is a popular ingredient in many European herbal products. Some research suggests it may help with certain coughs, but the evidence is still limited and mixed. The raw plant is poisonous if eaten and can irritate skin, so only use properly prepared commercial products and check with your pharmacist first.

Read the full English Ivy monograph & all interactions
Medication

About Codeine

What Is Codeine Used For?

Brand name: Codeine

Codeine Sulfate tablets are used for the management of mild to moderate pain in adults and adolescents when other treatments have not worked well enough or are not tolerated. It is an opioid medication, so it is only appropriate when non-opioid options are inadequate.

Because of its serious risks — including addiction, misuse, and overdose — codeine is reserved for patients who truly need an opioid. Prescribers are expected to use the lowest effective dose for the shortest time possible.

See full Codeine drug information
Keep checking

Other Drugs & English Ivy

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

0Major
279Moderate
0Minor
2,550No known interaction
279 Moderate 2,550 No interaction
Moderate

279 interactions

Showing 60 of 279 moderate interactions — see all 279 on the English Ivy page.

No interaction 2,550 drugs checked — show the list

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

Showing the 60 most looked-up of 2,550 medications checked with no known interaction — see the full English Ivy list.

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

Can you take English Ivy with Codeine Phosphate?
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 English Ivy and Codeine Phosphate 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 Codeine Phosphate and English Ivy?

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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.