Drug & supplement interaction

Fo-ti + Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine

Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine brand names: Tylenol Cold Ex Strength, Children's Tylenol Cold Plus Cough.

Moderate Interaction
The bottom line Moderate

Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine falls into 4 drug categories that Fo-ti can interact with; the most serious is rated moderate. Theoretically, fo-ti may increase the levels and clinical effects of drugs metabolized by CYP2D6.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions4
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Fo-ti and Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine

These two interact in 4 distinct ways. Each one is explained separately below.

Why Are There 4 Interactions?

Fo-ti interacts with whole categories of medication. Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine falls into 4 of those categories, so it can interact with Fo-ti in 4 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

1 of 4

Why this applies to Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine

Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES — the group Fo-ti interacts with.

Theoretically, fo-ti may increase the levels and clinical effects of drugs metabolized by CYP2D6.
Animal research suggests that fo-ti might inhibit CYP2D6. Additionally, an in vitro study suggests that the degree of CYP2D6 inhibition may depend on the type of fo-ti extract (i.e., the raw plant leads to greater inhibition than extensively processed extracts). However, 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

This is a multi-ingredient cold and cough product, and the one piece that really matters here is the dextromethorphan (the cough suppressant). Your body relies on a liver enzyme called CYP2D6 to break it down. Lab and animal studies hint that Fo-ti, especially the raw, less-processed root, might slow that enzyme down. If that happened, dextromethorphan could build up a bit and lead to more drowsiness, dizziness, or feeling foggy.

I want to be honest though: this is theoretical. It has only been seen in test tubes and animals, never reported in real people. For most folks taking this combo short-term for a cold, it's unlikely to cause trouble. Still, if you use Fo-ti regularly, it's worth a quick chat with your pharmacist before mixing them.

References
  1. Zhang Y, Ding T, Diao T, Deng M, Chen S. Effects of Polygonum multiflorum on the activity of cytochrome P450 isoforms in rats. Pharmazie 2015;70(1):47-54. DOI
  2. Xing Y, Yu Q, Zhou L, et al. Cytochrome P450-mediated herb-drug interaction (HDI) of Polygonum multiflorum Thunb. based on pharmacokinetic studies and in vitro inhibition assays. Phytomedicine 2023;112:154710. PubMed
Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

2 of 4

Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine also falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES.

Theoretically, fo-ti might increase or decrease the levels and clinical effects of drugs metabolized by CYP1A2.
In vitro research suggests that fo-ti might inhibit CYP1A2. Additionally, in vitro research suggests that the degree of CYP1A2 inhibition depends on the type of fo-ti extract (i.e., the raw plant leads to greater inhibition than extensively processed extracts). However, in an animal study, an aqueous extract of fo-ti inhibited CYP1A2 while an alcoholic extract of fo-ti induced CYP1A2. Induction or inhibition of CYP1A2 by fo-ti 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

This is one of those cold-and-cough combo products, and the piece that touches on fo-ti is the CYP1A2 enzyme. Your liver uses that enzyme to help clear certain medicines. In lab and animal studies, fo-ti has gone both ways: some forms slowed CYP1A2 down, while others sped it up. None of this has actually been shown in people, so consider it more of a theoretical heads-up than a proven problem.

If fo-ti were to slow that enzyme, levels of these ingredients could nudge higher, meaning a bit more drowsiness or dry mouth from the chlorpheniramine, or more jitteriness and a faster heartbeat from the pseudoephedrine. If it sped things up, the relief might feel weaker. Since fo-ti itself has been tied to liver issues and acetaminophen is hard on the liver too, it is worth a quick chat with your pharmacist before combining them.

References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  2. Zhang Y, Ding T, Diao T, Deng M, Chen S. Effects of Polygonum multiflorum on the activity of cytochrome P450 isoforms in rats. Pharmazie 2015;70(1):47-54. DOI
  3. Xing Y, Yu Q, Zhou L, et al. Cytochrome P450-mediated herb-drug interaction (HDI) of Polygonum multiflorum Thunb. based on pharmacokinetic studies and in vitro inhibition assays. Phytomedicine 2023;112:154710. PubMed
Moderate

HEPATOTOXIC DRUGS

3 of 4

Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine also falls under HEPATOTOXIC DRUGS.

Theoretically, fo-ti might increase the risk of liver damage when taken with hepatotoxic drugs.
Fo-ti has been linked to liver damage in many reports.
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

The piece of this cold medicine I want to focus on is the acetaminophen (the Tylenol part). Acetaminophen is processed by your liver, and in large or frequent doses it can stress the liver on its own. Fo-ti has been tied to reports of liver injury in some people, so the worry here is a doubling-up effect: two things leaning on the same organ at the same time.

To be clear, this is based on scattered case reports, not strong studies, so it's a theoretical concern rather than a proven one. Still, it's worth respecting. If you take this cold product, watch your total acetaminophen each day, and tell your pharmacist or doctor you're using Fo-ti, especially if you ever notice yellowing skin, dark urine, belly pain, or unusual tiredness.

References
  1. Park GJ, Mann SP, Ngu MC. Acute hepatitis induced by Shou-Wu-Pian, a herbal product derived from Polygonum multiflorum. J Gastroenterol Hepatol 2001;16:115-7.
  2. But PP, Tomlinson B, Lee KL. Hepatitis related to the Chinese medicine Shou-wu-pian manufactured from Polygonum multiflorum. Vet Hum Toxicol 1996;38:280-2.
  3. UK Medicines and Healthcare Products Regulatory Agency. Polygonum multiflorum and liver reactions. April 2006. Available at: www.mhra.gov.uk/home/idcplg?IdcService= SS_GET_PAGE&useSecondary=true&ssDocName= CON2023590&ssTargetNodeId= 833 (Accessed 10 May 2
  4. Panis B, Wong DR, Hooymans PM, De Smet PA, Rosias PP. Recurrent toxic hepatitis in a Caucasian girl related to the use of Shou-Wu-Pian, a Chinese herbal preparation. J Pediatr Gastroenterol Nutr 2005;41:256-8. PubMed
  5. Mazzanti G, Battinelli L, Daniele C, et al. New case of acute hepatitis following the consumption of Shou Wu Pian, a Chinese herbal product derived from Polygonum multiflorum. Ann Intern Med 2004;140:E589-90.
  6. Cardenas A, Restrepo JC, Sierra F, Correa G. Acute hepatitis due to shen-min: a herbal product derived from Polygonum multiflorum. J Clin Gastroenterol 2006;40:629-32. PubMed
  7. Laird AR, Ramchandani N, deGoma EM, et al. Acute hepatitis associated with the use of an herbal supplement (Polygonum multiflorum) mimicking iron-overload syndrome. J Clin Gastroenterol 2008;42:861-2. PubMed
  8. Jung KA, Min HJ, Yoo SS, et al. Drug-Induced Liver Injury: Twenty Five Cases of Acute Hepatitis Following Ingestion of Polygonum multiflorum Thunb. Gut Liver 2011;5(4):493-9. PubMed
  9. Yuen, M. F., Tam, S., Fung, J., Wong, D. K., Wong, B. C., and Lai, C. L. Traditional Chinese medicine causing hepatotoxicity in patients with chronic hepatitis B infection: a 1-year prospective study. Aliment.Pharmacol.Ther 10-15-2006;24(8):1179-1186. PubMed
  10. Bae, S. H., Kim, D. H., Bae, Y. S., Lee, K. J., Kim, D. W., Yoon, J. B., Hong, J. H., and Kim, S. H. [Toxic hepatitis associated with Polygoni multiflori]. Korean J.Hepatol. 2010;16(2):182-186. PubMed
  11. Furukawa, M., Kasajima, S., Nakamura, Y., Shouzushima, M., Nagatani, N., Takinishi, A., Taguchi, A., Fujita, M., Niimi, A., Misaka, R., and Nagahara, H. Toxic hepatitis induced by show-wu-pian, a Chinese herbal preparation. Intern.Med. 2010;49(15):1537-1 PubMed
  12. Dong H, Slain D, Cheng J, Ma W, Liang W. Eighteen cases of liver injury following ingestion of Polygonum multiflorum. Complement Ther Med 2014;22(1):70-4. PubMed
  13. Lei X, Chen J, Ren J, et al. Liver damage associated with Polygonum multiflorum Thunb.: a systematic review of case reports and case series. Evid Based Complement Alternat Med 2015;2015:459749.
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

4 of 4

Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, fo-ti might increase the levels and clinical effects of drugs metabolized by CYP3A4.
In vitro research suggests that fo-ti might inhibit CYP3A4. One in vitro study suggests that the degree of CYP3A4 inhibition may depend on the type of fo-ti extract (i.e., the raw plant leads to greater inhibition than extensively processed extracts). However, this evidence conflicts with animal research suggesting that fo-ti does not inhibit CYP3A4. 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

This combo cold product packs four ingredients, and a couple of them (especially dextromethorphan, the cough suppressant) are partly broken down by a liver enzyme called CYP3A4. The thinking here is that Fo-ti might slow that enzyme down a bit, which could let some of these ingredients build up slightly. In real life that might mean more drowsiness or dizziness from the chlorpheniramine and dextromethorphan, or feeling jittery from the pseudoephedrine. None of these are prodrugs, so blocking the enzyme would tend to strengthen their effects, not weaken them.

Honestly though, this is theoretical and only seen in lab testing, never reported in actual people, and animal studies even disagree. I wouldn't lose sleep over it, but since Fo-ti has its own liver-safety concerns, run it by your pharmacist before pairing them.

References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  2. Zhang Y, Ding T, Diao T, Deng M, Chen S. Effects of Polygonum multiflorum on the activity of cytochrome P450 isoforms in rats. Pharmazie 2015;70(1):47-54. DOI
  3. Xing Y, Yu Q, Zhou L, et al. Cytochrome P450-mediated herb-drug interaction (HDI) of Polygonum multiflorum Thunb. based on pharmacokinetic studies and in vitro inhibition assays. Phytomedicine 2023;112:154710. 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

Fo-ti Also Interacts With Other Medications

Fo-ti has 1,256 moderate known drug interactions in our database — the Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine one above is among them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Fo-ti

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

Everything else you take

See Every Supplement That Interacts With Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine

This page covers Fo-ti only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine page lists 301 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 · 242 moderate · 45 minor.

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

“Because Tylenol Cold Extra Strength packs four drugs into one dose (acetaminophen, chlorpheniramine, dextromethorphan, and pseudoephedrine), its supplement list runs to 301 ingredients, and 14 carry a major rating, so I'd approach this one with real care. The biggest hazards mirror the drugs themselves.”

Reviewed by 2 · Jul 18, 2026

Open the Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine interaction page

One more smart check

Taking Fo-ti as Part of a Dietary Supplement Product? Check It for Interactions

We hold 976 real supplement products containing Fo-ti, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Fo-ti. Your product may carry other ingredients that interact with Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine too, on top of Fo-ti — 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 Fo-ti and Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine 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 Fo-ti
Top 25%

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

29 days ago today
Medication Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine
Top 25%

#533 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 Fo-ti

What is Fo-ti?

  • Anti-aging and longevity
  • Hair graying and hair loss
  • General tonic for vitality
  • Constipation
  • High cholesterol

Fo-ti (He Shou Wu) is a root used in traditional Chinese medicine, often promoted for healthy aging and hair. High-quality human evidence for these benefits is limited, and processed Fo-ti has been linked to reports of liver injury, so caution and professional guidance are important.

Read the full Fo-ti monograph & all interactions
Keep checking

Other Drugs & Fo-ti

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

0Major
1,256Moderate
0Minor
1,573No known interaction
Moderate

1,256 interactions

Showing 60 of 1,256 moderate interactions — see all 1,256 on the Fo-ti page.

No interaction 1,573 drugs checked — show the list
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
Pharmacist Counseling Corner

Taking Fo-ti and Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine Together: Common Questions

Can you take Fo-ti with Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine?
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 4 interactions listed for Fo-ti and Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine?
Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine belongs to more than one drug category, and Fo-ti 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 Fo-ti and Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine 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, Chlorpheniramine, Dextromethorphan, Pseudoephedrine and Fo-ti?

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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.