Ayahuasca + Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine
Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine brand name: Theracaps.
Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine falls into 3 drug categories that Ayahuasca can interact with; the most serious is rated moderate. Theoretically, ayahuasca might increase levels of serotonin, which may have additive effects with serotonergic drugs.
Read the full interaction reportAyahuasca and Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine
These two interact in 3 distinct ways. Each one is explained separately below.
Why Are There 3 Interactions?
Ayahuasca interacts with whole categories of medication. Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine falls into 3 of those categories, so it can interact with Ayahuasca in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).
SEROTONERGIC DRUGS
1 of 3Why this applies to Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine
Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine falls under SEROTONERGIC DRUGS — the group Ayahuasca interacts with.
In vitro and animal research shows that harmaline and harmine, constituents of ayahuasca, strongly and reversibly inhibit monoamine oxidase A and weakly inhibit monoamine oxidase B. The dimethyltryptamine and tetrahydroharmine constituents of ayahuasca have also demonstrated serotonergic activity. A case of serotonin syndrome characterized by tremors, sweating, shivering, confusion, nausea, vomiting, and disorientation has been reported in a 36-year-old male who consumed 100 mL of ayahuasca while taking fluoxetine 20 mg daily. Combining serotonergic drugs with ayahuasca might increase the risk of serotonergic side effects including serotonin syndrome and cerebral vasoconstrictive disorders.
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 part of this combo cold product that matters most: the dextromethorphan (the cough suppressant). On its own it nudges serotonin upward, and ayahuasca acts like a strong MAO inhibitor that also raises serotonin. Stack those two together and you can get too much serotonin activity at once, which is what we call serotonin syndrome. Think agitation, sweating, shivering, a racing heart, tremors, confusion, even high fever. That's a real concern with MAOIs and dextromethorphan.
The phenylpropanolamine piece adds its own worry, since MAOIs can push blood pressure dangerously high. The acetaminophen and pyrilamine parts aren't the problem here. This is based on pharmacology and case reports, not just theory, so please don't mix these without talking to your pharmacist or doctor first.
- Kawanishi, K., Hashimoto, Y., Fujiwara, M., Kataoka, Y., and Ueki, S. Pharmacological characteristics of abnormal behavior induced by harmine with special reference to tremor in mice. J Pharmacobiodyn 1981;4(7):520-527. PubMed
- Herraiz, T., Gonzalez, D., Ancin-Azpilicueta, C., Aran, V. J., and Guillen, H. beta-Carboline alkaloids in Peganum harmala and inhibition of human monoamine oxidase (MAO). Food Chem Toxicol 2010;48(3):839-845. PubMed
- Fuller, R. W., Wong, C. J., and Hemrick-Luecke, S. K. MD 240928 and harmaline: opposite selectivity in antagonism of the inactivation of types A and B monoamine oxidase by pargyline in mice. Life Sci 1986;38(5):409-412. PubMed
- Abdel-Fattah, A. F., Matsumoto, K., Murakami, Y., Adel-Khalek, Gammaz H., Mohamed, M. F., and Watanabe, H. Central serotonin level-dependent changes in body temperature following administration of tryptophan to pargyline- and harmaline-pretreated rats. Ge PubMed
- Bergstrom, M., Westerberg, G., and Langstrom, B. 11C-harmine as a tracer for monoamine oxidase A (MAO-A): in vitro and in vivo studies. Nucl Med Biol 1997;24(4):287-293. PubMed
- Gerardy, J. Effect of moclobemide on rat brain monoamine oxidase A and B: comparison with harmaline and clorgyline. Prog Neuropsychopharmacol Biol Psychiatry 1994;18(4):793-802.
- Sacher, J., Houle, S., Parkes, J., Rusjan, P., Sagrati, S., Wilson, A. A., and Meyer, J. H. Monoamine oxidase A inhibitor occupancy during treatment of major depressive episodes with moclobemide or St. John's wort: an [11C]-harmine PET study. J Psychiatry
- dos Santos RG. Safety and side effects of ayahuasca in humans--an overview focusing on developmental toxicology. J Psychoactive Drugs. 2013 Jan-Mar;45(1):68-78. PubMed
- dos Santos RG. A critical evaluation of reports associating ayahuasca with life-threatening adverse reactions. J Psychoactive Drugs. 2013 Apr-Jun;45(2):179-88. PubMed
- Callaway JC, Grob CS. Ayahuasca preparations and serotonin reuptake inhibitors: a potential combination for severe adverse interactions. J Psychoactive Drugs. 1998 Oct-Dec;30(4):367-9. PubMed
CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES
2 of 3Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine also falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES.
Ayahuasca contains beta-carboline alkaloids, including harmine and harmaline. In vitro research suggests that the beta-carboline alkaloids might inhibit CYP2D6 enzymes. This effect has not been reported in humans.
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..
Your Theracaps combo includes dextromethorphan, the cough suppressant, and this is the piece that matters most here. Dextromethorphan is cleared from your body by a liver enzyme called CYP2D6. Lab studies hint that the harmine and harmaline in ayahuasca can block that enzyme, so dextromethorphan could build up instead of being cleared at the usual pace.
If that happens, you might feel more dizziness, drowsiness, or confusion than expected. There is also a bigger worry: ayahuasca acts like an MAOI, and combining MAOIs with dextromethorphan can rarely trigger dangerous serotonin reactions (agitation, fast heartbeat, high temperature). This interaction is only shown in lab work, not proven in people, but given ayahuasca's risks, please check with your pharmacist or doctor first.
- Zhao, T., He, Y. Q., Wang, J., Ding, K. M., Wang, C. H., and Wang, Z. T. Inhibition of human cytochrome P450 enzymes 3A4 and 2D6 by β-carboline alkaloids, harmine derivatives. Phytother Res 2011;25(11):1671-1677.
- dos Santos RG. Safety and side effects of ayahuasca in humans--an overview focusing on developmental toxicology. J Psychoactive Drugs. 2013 Jan-Mar;45(1):68-78. PubMed
CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES
3 of 3Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.
Ayahuasca contains beta-carboline alkaloids. In vitro research suggests that beta-carboline alkaloids competitively inhibit CYP3A4 enzymes. This effect has not been reported in humans.
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 combination cold-and-allergy product (Theracaps) bundles acetaminophen, dextromethorphan, phenylpropanolamine, and pyrilamine together. The concern on file is mostly lab-based: compounds in ayahuasca can compete with the CYP3A4 enzyme that helps clear some of these ingredients, so in theory their levels could climb. This has only been seen in test-tube studies, not in people, so the real-world risk is uncertain and likely small.
The bigger worry is actually different. Ayahuasca acts like an MAOI, and mixing an MAOI with dextromethorphan (a cough suppressant) can cause serotonin syndrome, with agitation, fast heartbeat, sweating, and dangerously high body temperature. That can be serious. Please don't combine these without talking to your pharmacist or doctor first.
- Zhao, T., He, Y. Q., Wang, J., Ding, K. M., Wang, C. H., and Wang, Z. T. Inhibition of human cytochrome P450 enzymes 3A4 and 2D6 by β-carboline alkaloids, harmine derivatives. Phytother Res 2011;25(11):1671-1677.
- dos Santos RG. Safety and side effects of ayahuasca in humans--an overview focusing on developmental toxicology. J Psychoactive Drugs. 2013 Jan-Mar;45(1):68-78. PubMed
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.
Ayahuasca Also Interacts With Other Medications
Ayahuasca has 803 moderate known drug interactions in our database — the Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine one above is among them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Ayahuasca
We haven’t checked that one against Ayahuasca yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Ayahuasca. Pick one to open its full report.
See Every Supplement That Interacts With Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine
This page covers Ayahuasca only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine page lists 282 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 · 223 moderate · 45 minor.
From our pharmacist’s overview on the Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine page
“Of everything on this page, ephedra worries me most for anyone using Theracaps (acetaminophen, dextromethorphan, phenylpropanolamine, and pyrilamine), because the decongestant in this cold formula is itself a stimulant. Adding ephedra or any of the 44 stimulant entries can push blood pressure and heart rate to unsafe levels.”
Reviewed by 2 · Jul 18, 2026
Open the Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine interaction page
Where Ayahuasca and Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine 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.
#964 of 1,452 supplements looked up here in the last 7 days
#222 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 Ayahuasca
What is Ayahuasca?
- Spiritual and ceremonial rituals
- Depression
- Anxiety
- Substance use disorders
- Personal or emotional insight
Ayahuasca is a powerful psychoactive brew that combines a DMT-containing plant with a vine that allows the DMT to take effect, causing intense hallucinations. It is illegal in many places, can trigger dangerous reactions, and is not recommended for self-use; talk to a doctor or pharmacist before considering it.
Other Drugs & Ayahuasca
Browse every other medication we’ve checked against Ayahuasca — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
803 interactions
- Diltiazem ›
- Nifedipine ›
- Hydrocortisone ›
- Methylphenidate ›
- Erythromycin ›
- Estradiol ›
- Propranolol ›
- Lidocaine ›
- Norethindrone ›
- Testosterone ›
- Verapamil ›
- Levonorgestrel ›
- Prednisone ›
- Quinidine ›
- Cyclosporine ›
- Dexamethasone ›
- Triazolam ›
- Zopiclone ›
- Colchicine ›
- Fentanyl ›
- Oxybutynin ›
- Oxycodone ›
- Prednisolone ›
- Tacrolimus ›
- Temazepam ›
- Apomorphine ›
- Budesonide ›
- Carbamazepine ›
- Clindamycin ›
- Dextromethorphan ›
- Doxorubicin ›
- Fluticasone ›
- Formoterol ›
- Miconazole ›
- Morphine Sulfate ›
- Phenylephrine ›
- Trimipramine ›
- Amphetamine ›
- Buprenorphine ›
- Conjugated Estrogens ›
- Diazepam ›
- Everolimus ›
- Ivabradine ›
- Lofepramine ›
- Medroxyprogesterone ›
- Medroxyprogesterone Acetate ›
- Nortriptyline ›
- Propoxyphene ›
- Rifampin ›
- Selegiline ›
- Sumatriptan Succinate ›
- Testosterone Undecanoate ›
- Aripiprazole ›
- Caffeine (otc Drug) ›
- Ciclesonide ›
- Clonazepam ›
- Cyclobenzaprine ›
- Dapsone ›
- Desipramine ›
- Doxepin ›
Showing 60 of 803 moderate interactions — see all 803 on the Ayahuasca page.
No interaction 2,026 drugs checked — show the list
We also checked Ayahuasca against these medications and found no known interaction in our sources. Open any page to confirm.
- Levothyroxine ›
- Ivermectin ›
- Aspirin ›
- Acetaminophen ›
- Rosuvastatin ›
- Docusate ›
- Tirzepatide ›
- Ibuprofen ›
- Hydroxyurea ›
- Valacyclovir ›
- Semaglutide ›
- Metformin ›
- Lisinopril ›
- Amoxicillin ›
- Isotretinoin ›
- Methotrexate ›
- Bupropion ›
- Bendamustine ›
- Doxycycline ›
- Acyclovir ›
- Azithromycin ›
- Lamotrigine ›
- Pregabalin ›
- Gabapentin ›
- Naproxen ›
- Levothyroxine, Liothyronine ›
- Ciprofloxacin ›
- Candesartan Cilexetil ›
- Amoxicillin, Clavulanate Potassium ›
- Acetaminophen, Dextromethorphan, Doxylamine ›
- Cyclopentolate ›
- Cephalexin ›
- Mannitol ›
- Roxithromycin ›
- Levetiracetam ›
- Ezetimibe ›
- Acetaminophen, Aspirin ›
- Acetylsalicylic Acid ›
- Phentermine, Topiramate ›
- Levothyroxine Sodium ›
- Acetaminophen, Ibuprofen ›
- Thyroid Hormone ›
- Spironolactone ›
- Pizotifen ›
- Daptomycin ›
- Valsartan ›
- Pegunigalsidase Alfa-iwxj ›
- Mitomycin ›
- Hexobarbitone ›
- Flutemetamol F-18 ›
- Magnesium Hydroxide (otc Drug) ›
- Bentoquatam ›
- Cefaclor ›
- Factor 7a ›
- Insulin Degludec, Liraglutide ›
- Canagliflozin, Metformin ›
- Hethylphenidate Hcl ›
- Azelaic Acid ›
- Alglucosidase Alpha ›
- Ibuprofen, Acetaminophen ›
Showing the 60 most looked-up of 2,026 medications checked with no known interaction — see the full Ayahuasca 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, Dextromethorphan, Phenylpropanolamine, Pyrilamine Is Linked to Lower Levels of One Nutrient
Natural Medicines records Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine as a medicine that can lower these. This is not an interaction with Ayahuasca — it is a separate effect of the medicine, and it is a reason some people are advised to supplement rather than to avoid one:
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 Ayahuasca and Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine Together: Common Questions
Can you take Ayahuasca with Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine?
Why are there 3 interactions listed for Ayahuasca and Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine?
How serious is the Ayahuasca and Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine 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.