Rooibos + Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine
Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine brand name: Colrex.
Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine falls into 3 drug categories that Rooibos can interact with; the most serious is rated moderate. Theoretically, taking rooibos with CYP1A2 substrates may increase the effects of CYP1A2 substrates.
Read the full interaction reportRooibos and Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine
These two interact in 3 distinct ways. Each one is explained separately below.
Why Are There 3 Interactions?
Rooibos interacts with whole categories of medication. Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine falls into 3 of those categories, so it can interact with Rooibos in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).
CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES
1 of 3Why this applies to Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine
Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Rooibos interacts with.
In vitro research shows that the methanol extract of rooibos leaves and stems inhibits CYP1A2 enzyme activity.
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.
Here's the honest picture with Colrex, which is a combo of acetaminophen, chlorpheniramine, codeine, and phenylephrine. The concern on file is that rooibos might block an enzyme called CYP1A2, which could in theory slow how your body clears certain medicines and let their effects run a little stronger. But this idea comes only from lab dish studies, not from people, so the real-world risk is quite low.
If anything did shift, you might notice a bit more drowsiness, dizziness, or dry mouth from the antihistamine and codeine pieces. A cup or two of rooibos tea is very unlikely to cause trouble. I'd be more cautious with concentrated rooibos extracts. When in doubt, run it by your pharmacist.
- Fantoukh OI, Dale OR, Parveen A, et al. Safety Assessment of Phytochemicals Derived from the Globalized South African Rooibos Tea (Aspalathus linearis) through Interaction with CYP, PXR, and P-gp. J Agric Food Chem. 2019;67(17):4967-4975.
CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES
2 of 3Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine also falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES.
In vitro research shows that the methanol extract of rooibos leaves and stems inhibits CYP2D6 enzyme activity.
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.
This is one of those cold and cough combos, and the piece worth talking about is the codeine. Codeine is a prodrug, meaning your body has to convert it (using an enzyme called CYP2D6) into morphine before it does much for pain or coughing. Lab studies hint that rooibos may slow that same enzyme. In theory, that could mean less codeine gets turned into its active form, so you might get a bit less cough or pain relief.
Honestly, this is only based on test-tube research, not real people, and drinking rooibos as a regular tea is very unlikely to cause a problem. Concentrated rooibos extracts are the bigger unknown. If you rely on this medicine and want to use rooibos supplements, just run it by your pharmacist or doctor first.
- Fantoukh OI, Dale OR, Parveen A, et al. Safety Assessment of Phytochemicals Derived from the Globalized South African Rooibos Tea (Aspalathus linearis) through Interaction with CYP, PXR, and P-gp. J Agric Food Chem. 2019;67(17):4967-4975.
CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES
3 of 3Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.
In vitro research shows that the methanol extract of rooibos leaves and stems strongly inhibits CYP3A4 enzyme activity.
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.
Colrex is a combination cold medicine, and one ingredient worth watching here is codeine. Codeine is a prodrug, meaning your body has to convert it into its active painkilling form. The lab note on file suggests rooibos might block a liver enzyme called CYP3A4, which helps clear codeine and process other ingredients in this product. If that enzyme slows down, more codeine and its byproducts could linger, which in theory could nudge up effects like drowsiness, constipation, dizziness, or slowed breathing.
Here's my honest take: this is based only on test-tube research, not real people, and a cup of rooibos tea is very unlikely to cause trouble. Concentrated rooibos extracts are a different story. If you use those, check with your pharmacist or doctor first.
- Fantoukh OI, Dale OR, Parveen A, et al. Safety Assessment of Phytochemicals Derived from the Globalized South African Rooibos Tea (Aspalathus linearis) through Interaction with CYP, PXR, and P-gp. J Agric Food Chem. 2019;67(17):4967-4975.
What These Ratings Mean
Every interaction above is graded three ways — here’s the key to each label.
Clinically significant. Avoid the combination, or use only under close professional supervision.
Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.
Generally not serious. Be aware of it and mention it to your pharmacist.
- 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.
- 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.
Rooibos Also Interacts With Other Medications
Rooibos has 878 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.
Check Another of Your Medications Against Rooibos
We haven’t checked that one against Rooibos yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Rooibos. Pick one to open its full report.
See Every Supplement That Interacts With Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine
This page covers Rooibos 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
Taking Rooibos as Part of a Dietary Supplement Product? Check It for Interactions
We hold 142 real supplement products containing Rooibos, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Rooibos. Your product may carry other ingredients that interact with Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine too, on top of Rooibos — and those would not show on this page. Find your product and we’ll check every ingredient on its label:
Where Rooibos 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.
#599 of 1,452 supplements looked up here in the last 7 days
#269 of 2,830 medications looked up here in the last 7 days
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.
About Rooibos
What is Rooibos?
- Caffeine-free beverage
- Antioxidant support
- Heart health
- Blood sugar support
- Digestive upset
- General wellness
Rooibos is a caffeine-free herbal tea from South Africa that is rich in antioxidants and generally considered safe as a beverage. While lab and early studies suggest possible benefits for heart health, blood sugar, and inflammation, strong human evidence is lacking for most medical uses. Enjoy it as a tea, but talk to your pharmacist or doctor before using concentrated extracts for health reasons.
Other Drugs & Rooibos
Browse every other medication we’ve checked against Rooibos — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
878 interactions
- Diclofenac Sodium ›
- Diltiazem ›
- Theophylline ›
- Nifedipine ›
- Ibuprofen ›
- Hydrocortisone ›
- Naproxen ›
- Erythromycin ›
- Estradiol ›
- Propranolol ›
- Lidocaine ›
- Norethindrone ›
- Testosterone ›
- Verapamil ›
- Levonorgestrel ›
- Prednisone ›
- Quinidine ›
- Cyclosporine ›
- Dexamethasone ›
- Glyburide ›
- Triazolam ›
- Zopiclone ›
- Colchicine ›
- Fentanyl ›
- Flurbiprofen ›
- Oxybutynin ›
- Oxycodone ›
- Phenytoin ›
- Prednisolone ›
- Tacrolimus ›
- Temazepam ›
- Budesonide ›
- Carbamazepine ›
- Clindamycin ›
- Dextromethorphan ›
- Diclofenac Potassium ›
- Doxorubicin ›
- Fluticasone ›
- Formoterol ›
- Indomethacin ›
- Miconazole ›
- Morphine Sulfate ›
- Trimipramine ›
- Acetaminophen ›
- Amphetamine ›
- Buprenorphine ›
- Conjugated Estrogens ›
- Diazepam ›
- Everolimus ›
- Ivabradine ›
- Lofepramine ›
- Medroxyprogesterone ›
- Medroxyprogesterone Acetate ›
- Meloxicam ›
- Nortriptyline ›
- Propoxyphene ›
- Rifampin ›
- Testosterone Undecanoate ›
- Aripiprazole ›
- Bendamustine ›
Showing 60 of 878 moderate interactions — see all 878 on the Rooibos page.
No interaction 1,951 drugs checked — show the list
We also checked Rooibos against these medications and found no known interaction in our sources. Open any page to confirm.
- Levothyroxine ›
- Methylphenidate ›
- Aspirin ›
- Ivermectin ›
- Rosuvastatin ›
- Escitalopram ›
- Docusate ›
- Valacyclovir ›
- Hydroxyurea ›
- Sumatriptan ›
- Semaglutide ›
- Tirzepatide ›
- Bupropion ›
- Metformin ›
- Amoxicillin ›
- Acyclovir ›
- Doxycycline ›
- Methotrexate ›
- Lamotrigine ›
- Gabapentin ›
- Pregabalin ›
- Azithromycin ›
- Isotretinoin ›
- Methylene Blue ›
- Ciprofloxacin ›
- Levothyroxine, Liothyronine ›
- Cyclopentolate ›
- Candesartan Cilexetil ›
- Cephalexin ›
- Mannitol ›
- Roxithromycin ›
- Acetaminophen, Dextromethorphan, Doxylamine ›
- Pegunigalsidase Alfa-iwxj ›
- Daptomycin ›
- Hexobarbitone ›
- Levothyroxine Sodium ›
- Levetiracetam ›
- Dexmethylphenidate ›
- Factor 7a ›
- Carbidopa, Levodopa ›
- Thyroid Hormone ›
- Minoxidil ›
- Mitomycin ›
- Levodopa ›
- Cefaclor ›
- Ezetimibe ›
- Spironolactone ›
- Lenvatinib ›
- Vancomycin ›
- Phenylephrine ›
- Hethylphenidate Hcl ›
- Phentermine, Topiramate ›
- Bentoquatam ›
- Dirithromycin ›
- Procainamide ›
- Tenecteplase ›
- Hydroxychloroquine ›
- Amoxicillin, Clavulanate Potassium ›
- Digoxin ›
- Azelaic Acid ›
Showing the 60 most looked-up of 1,951 medications checked with no known interaction — see the full Rooibos list.
Sources & How We Checked
Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference for vitamins, herbs and supplements — the basis for our interaction data.
- MedlinePlus, U.S. National Library of Medicine — NIH consumer drug information, used for the medication overviews.
- NIH Dietary Supplement Label Database (DSLD) — Official supplement product labels.
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
Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine Is Linked to Lower Levels of One Nutrient
Natural Medicines records Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine as a medicine that can lower these. This is not an interaction with Rooibos — it is a separate effect of the medicine, and it is a reason some people are advised to supplement rather than to avoid one:
Read the full Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine nutrient depletion report ›
Depletion records come from the licensed Natural Medicines database. Do not start a supplement on the strength of this page — ask your pharmacist or doctor whether it applies to you.
Taking Rooibos and Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine Together: Common Questions
Can you take Rooibos with Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine?
Why are there 3 interactions listed for Rooibos and Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine?
How serious is the Rooibos and Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine interaction?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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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.