Drug & supplement interaction

Chenopodium Oil + Chlorpheniramine, Phenylephrine

Chlorpheniramine, Phenylephrine brand names: Histatab Plus, Ed A Hist, Rynatan, Dallergy JR.

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

Chenopodium Oil has a moderate interaction with Chlorpheniramine, Phenylephrine. Theoretically, concomitant use of chenopodium oil with other photosensitizing drugs can increase the risk of adverse effects.

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

Chenopodium Oil and Chlorpheniramine, Phenylephrine

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

Moderate

PHOTOSENSITIZING DRUGS

Why this applies to Chlorpheniramine, Phenylephrine

Chlorpheniramine, Phenylephrine falls under PHOTOSENSITIZING DRUGS — the group Chenopodium Oil interacts with.

Theoretically, concomitant use of chenopodium oil with other photosensitizing drugs can increase the risk of adverse effects.
Chenopodium species are also associated with photosensitivity.
Severity Moderate Likelihood Probable Evidence D

Interaction 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..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the simple version. This combo isn't about how your body breaks down the medicine. Instead, the concern is your skin. Both chenopodium oil and the antihistamine cold combo (chlorpheniramine and phenylephrine) have been linked to photosensitivity, which just means your skin may sunburn more easily than usual. Put them together and that effect could add up, so you might burn faster after time outside.

I want to be honest about the strength of this: it's theoretical, based on how these substances behave, not on solid patient studies. So don't panic. If you use both, be smart in the sun (sunscreen, hat, shade) and check with your pharmacist before starting chenopodium oil, since it carries real safety concerns on its own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

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

Chenopodium Oil Also Interacts With Other Medications

Chenopodium Oil has 334 moderate known drug interactions in our database — the Chlorpheniramine, Phenylephrine one above is one of them. If you take anything else, check it against the full list below.

Moderate 334 No known interaction 2,496 (incl. Chlorpheniramine, Phenylephrine)
Taking anything else?

Check Another of Your Medications Against Chenopodium Oil

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

Everything else you take

See Every Supplement That Interacts With Chlorpheniramine, Phenylephrine

This page covers Chenopodium Oil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Chlorpheniramine, Phenylephrine page lists 229 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Ephedra (major), Grapefruit (major), Henbane (major) and Lithium (major).

By severity: 10 major · 175 moderate · 44 minor.

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

“A medicine that stimulates the heart and dries the body doesn't leave much room for supplements pulling the same way, and that describes chlorpheniramine, phenylephrine (Histatab Plus, Ed A Hist, Rynatan) well. Dozens of stimulant herbs, everyday caffeine sources among them, add to the decongestant's strain on blood pressure and heart…”

Reviewed by 2 · Jul 18, 2026

Open the Chlorpheniramine, Phenylephrine interaction page

One more smart check

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

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

#1,422 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Chlorpheniramine, Phenylephrine
Top half

#1,138 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 Chenopodium Oil

What is Chenopodium Oil?

Chenopodium Oil
  • Intestinal worms (roundworm, hookworm)
  • Digestive upset and gas
  • Respiratory complaints
  • Skin conditions
  • As a culinary seasoning (epazote leaf)

Chenopodium oil is a strong-smelling essential oil from the epazote plant that was historically used to treat intestinal worms. It contains ascaridole, a compound that is quite toxic, and overdoses have caused serious harm, so it is no longer recommended for internal use. Safer modern deworming medicines exist, so talk with a pharmacist or doctor before using this oil.

Read the full Chenopodium Oil monograph & all interactions
Keep checking

Other Drugs & Chenopodium Oil

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

0Major
334Moderate
0Minor
2,495No known interaction
334 Moderate 2,495 No interaction
Moderate

334 interactions

Showing 60 of 334 moderate interactions — see all 334 on the Chenopodium Oil page.

No interaction 2,495 drugs checked — show the list

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

Showing the 60 most looked-up of 2,495 medications checked with no known interaction — see the full Chenopodium Oil list.

See the full Chenopodium Oil interactions page
See every supplement checked against Chlorpheniramine, 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
Chenopodium Oil monograph › Uses, safety, and every drug interaction in one place Chlorpheniramine, Phenylephrine supplement interactions › Every supplement checked against Chlorpheniramine, 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 Chenopodium Oil and Chlorpheniramine, Phenylephrine Together: Common Questions

Can you take Chenopodium Oil with Chlorpheniramine, 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.
How serious is the Chenopodium Oil and Chlorpheniramine, 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 Chlorpheniramine, Phenylephrine and Chenopodium Oil?

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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.