Drug & supplement interaction

Lemongrass + Acetaminophen, Phenylephrine, Chlorpheniramine

Acetaminophen, Phenylephrine, Chlorpheniramine brand name: Super Cold Tabs.

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

Acetaminophen, Phenylephrine, Chlorpheniramine falls into 2 drug categories that Lemongrass can interact with; the most serious is rated moderate. Theoretically, lemongrass might decrease the metabolism of CYP3A4 substrates.

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

Lemongrass and Acetaminophen, Phenylephrine, Chlorpheniramine

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

Why Are There 2 Interactions?

Lemongrass interacts with whole categories of medication. Acetaminophen, Phenylephrine, Chlorpheniramine falls into 2 of those categories, so it can interact with Lemongrass 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 3A4 (CYP3A4) SUBSTRATES

1 of 2

Why this applies to Acetaminophen, Phenylephrine, Chlorpheniramine

Acetaminophen, Phenylephrine, Chlorpheniramine falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Lemongrass interacts with.

Theoretically, lemongrass might decrease the metabolism of CYP3A4 substrates.
Animal research shows that lemongrass and its constituent citral inhibit CYP3A4.
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 combo cold tablet has three active ingredients — a pain/fever reducer (acetaminophen), a decongestant (phenylephrine), and an antihistamine (chlorpheniramine). The idea here is that lemongrass might slow down a liver enzyme called CYP3A4, which helps clear some of these ingredients. If that enzyme works more slowly, a little more of the drug could linger in your body, which could mean stronger or longer-lasting effects — think more drowsiness, dry mouth, or dizziness from the antihistamine, or a bit more of the jittery, raised-blood-pressure feeling from phenylephrine.

Here's the reassuring part: this is only a theoretical concern based on lab and animal studies, not real human cases, and the lemongrass in tea or cooking is very unlikely to cause trouble. Concentrated supplements or the essential oil are a different story. If you use those, just check with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Li CC, Yu HF, Chang CH, Liu YT, Yao HT. Effects of lemongrass oil and citral on hepatic drug-metabolizing enzymes, oxidative stress, and acetaminophen toxicity in rats. J Food Drug Anal 2018;26(1):432-8. PubMed
Moderate

GLUCURONIDATED DRUGS

2 of 2

Acetaminophen, Phenylephrine, Chlorpheniramine also falls under GLUCURONIDATED DRUGS.

Theoretically, lemongrass might increase the clearance and decrease the levels of glucuronidated drugs.
Animal research shows that lemongrass and its constituent citral induce uridine diphosphoglucuronosyl transferase (UGT), the major phase 2 enzyme that is responsible for glucuronidation.
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 with your Super Cold Tabs combo and lemongrass. The acetaminophen piece is partly cleared by a process called glucuronidation. In lab and animal studies only, lemongrass (and its lemony compound citral) seemed to speed up that pathway. In theory, that could clear acetaminophen a little faster and lower its levels, which might mean slightly less fever and pain relief. We have no good human evidence this actually happens.

The phenylephrine and chlorpheniramine parts aren't really driven by this pathway, so I wouldn't expect a meaningful change there. A cup of lemongrass tea or food seasoning is very unlikely to matter. If you're using concentrated lemongrass supplements or the essential oil regularly, just check in with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Li CC, Yu HF, Chang CH, Liu YT, Yao HT. Effects of lemongrass oil and citral on hepatic drug-metabolizing enzymes, oxidative stress, and acetaminophen toxicity in rats. J Food Drug Anal 2018;26(1):432-8. 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

Lemongrass Also Interacts With Other Medications

Lemongrass has 707 moderate known drug interactions in our database — the Acetaminophen, Phenylephrine, Chlorpheniramine one above is among them. If you take anything else, check it against the full list below.

Moderate 707 No known interaction 2,123 (incl. Acetaminophen, Phenylephrine, Chlorpheniramine)
Taking anything else?

Check Another of Your Medications Against Lemongrass

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

Everything else you take

See Every Supplement That Interacts With Acetaminophen, Phenylephrine, Chlorpheniramine

This page covers Lemongrass only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Phenylephrine, Chlorpheniramine page lists 289 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 14 major · 229 moderate · 46 minor.

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

“Super Cold Tabs earns more caution than a cold remedy usually gets. It combines acetaminophen, the decongestant phenylephrine, and the antihistamine chlorpheniramine, and 14 of the 289 supplements on file interact at a major level, so those are the ones to understand first.”

Reviewed by 2 · Jul 18, 2026

Open the Acetaminophen, Phenylephrine, Chlorpheniramine interaction page

One more smart check

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

We hold 417 real supplement products containing Lemongrass, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Lemongrass. Your product may carry other ingredients that interact with Acetaminophen, Phenylephrine, Chlorpheniramine too, on top of Lemongrass — 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 Lemongrass and Acetaminophen, Phenylephrine, Chlorpheniramine 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 Lemongrass
Top half

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

29 days ago today
Medication Acetaminophen, Phenylephrine, Chlorpheniramine
Top 25%

#307 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 Lemongrass

What is Lemongrass?

Lemongrass
  • Digestive upset
  • Anxiety and stress
  • Antimicrobial/antifungal
  • Insect repellent
  • Flavoring in food and drinks

Lemongrass is a fragrant tropical grass widely used as a cooking herb, a tea, and an aromatherapy oil. It is generally considered safe in the small amounts used in food, but most of its claimed health benefits come from laboratory or animal studies rather than strong human research. Talk with your pharmacist or doctor before using concentrated supplements or the essential oil, especially if you are pregnant or breastfeeding.

Read the full Lemongrass monograph & all interactions
Keep checking

Other Drugs & Lemongrass

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

0Major
707Moderate
0Minor
2,122No known interaction
707 Moderate 2,122 No interaction
Moderate

707 interactions

Showing 60 of 707 moderate interactions — see all 707 on the Lemongrass page.

No interaction 2,122 drugs checked — show the list

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

Showing the 60 most looked-up of 2,122 medications checked with no known interaction — see the full Lemongrass list.

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

Can you take Lemongrass with Acetaminophen, Phenylephrine, Chlorpheniramine?
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 Lemongrass and Acetaminophen, Phenylephrine, Chlorpheniramine?
Acetaminophen, Phenylephrine, Chlorpheniramine belongs to more than one drug category, and Lemongrass 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 Lemongrass and Acetaminophen, Phenylephrine, Chlorpheniramine 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, Phenylephrine, Chlorpheniramine and Lemongrass?

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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.