Fo-ti + Aspirin, Codeine Phosphate, Phenobarbital
Aspirin, Codeine Phosphate, Phenobarbital brand name: Phenaphen.
Aspirin, Codeine Phosphate, Phenobarbital falls into 3 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 reportFo-ti and Aspirin, Codeine Phosphate, Phenobarbital
These two interact in 3 distinct ways. Each one is explained separately below.
Why Are There 3 Interactions?
Fo-ti interacts with whole categories of medication. Aspirin, Codeine Phosphate, Phenobarbital falls into 3 of those categories, so it can interact with Fo-ti in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).
CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES
1 of 3Why this applies to Aspirin, Codeine Phosphate, Phenobarbital
Aspirin, Codeine Phosphate, Phenobarbital falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES — the group Fo-ti interacts with.
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.
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 wrinkle with this combo product: the codeine part matters most. Codeine is a prodrug, meaning your body has to convert it through an enzyme called CYP2D6 into morphine, which is what actually relieves pain. Fo-ti has shown in lab and animal studies that it might slow down that very enzyme. In theory, that could mean less of your codeine gets turned into the active painkiller, so you might get weaker pain relief than expected.
I want to be honest, though: this is based on test-tube and animal research only, and it hasn't been seen in real people. Raw fo-ti seems to block the enzyme more than processed forms. The aspirin and phenobarbital pieces aren't really driven by CYP2D6. Still, please check with your pharmacist or doctor before pairing these.
- 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
- 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
ANTICOAGULANT/ANTIPLATELET DRUGS
2 of 3Aspirin, Codeine Phosphate, Phenobarbital also falls under ANTICOAGULANT/ANTIPLATELET DRUGS.
Some of these drugs include aspirin, clopidogrel (Plavix), dalteparin (Fragmin), dipyridamole (Persantine), enoxaparin (Lovenox), heparin, ticlopidine (Ticlid), warfarin (Coumadin), and others.
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.
The piece of this combination pill I want to flag is the aspirin. Aspirin already thins the blood a little by quieting your platelets. Fo-ti's concern here isn't a typical enzyme tug-of-war. The worry is that processed Fo-ti has occasionally been tied to liver injury, and your liver is where many of your clotting factors are made. If the liver gets stressed, clotting can weaken, and stacking that on top of aspirin could nudge your bleeding risk up.
Honestly, this is based on a few scattered case reports, not strong studies, so I don't want to alarm you. Still, watch for easy bruising, nosebleeds, dark stools, or bleeding that won't stop, plus any yellowing of the skin or eyes. Please check with your pharmacist or doctor before pairing these.
- 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
CYTOCHROME P450 2B6 (CYP2B6) SUBSTRATES
3 of 3Aspirin, Codeine Phosphate, Phenobarbital also falls under CYTOCHROME P450 2B6 (CYP2B6) SUBSTRATES.
Animal research suggests that fo-ti might inhibit CYP2B6. One in vitro study suggests that the degree of CYP2B6 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.
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 pill pairs aspirin, codeine, and phenobarbital. The piece that matters here is the phenobarbital, a barbiturate that's partly broken down by an enzyme called CYP2B6. In lab and animal studies, fo-ti (especially the raw, less-processed root) appears to slow that enzyme down. In theory, that could let phenobarbital build up a bit, leading to more drowsiness, dizziness, slowed breathing, or grogginess, which would also stack with the sedating effect of the codeine.
I want to be honest about the strength of this: it's based only on lab and animal work and has never actually been reported in people, so treat it as a caution, not an alarm. Still, since phenobarbital is a drug where small shifts can matter, please check with your pharmacist or doctor before combining the two.
- 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
- 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.
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.
Fo-ti Also Interacts With Other Medications
Fo-ti has 1,256 moderate known drug interactions in our database — the Aspirin, Codeine Phosphate, Phenobarbital one above is among them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Fo-ti
We haven’t checked that one against Fo-ti yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Fo-ti. Pick one to open its full report.
See Every Supplement That Interacts With Aspirin, Codeine Phosphate, Phenobarbital
This page covers Fo-ti only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aspirin, Codeine Phosphate, Phenobarbital page lists 352 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 Danshen (major).
By severity: 12 major · 304 moderate · 36 minor.
From our pharmacist’s overview on the Aspirin, Codeine Phosphate, Phenobarbital page
“Alcohol is the entry I would flag first with Phenaphen (aspirin, codeine phosphate, phenobarbital): beer or wine layered onto codeine and phenobarbital can deepen sedation and, at worst, slow breathing. This medication deserves real caution with supplements.”
Reviewed by 2 · Jul 18, 2026
Open the Aspirin, Codeine Phosphate, Phenobarbital interaction page
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 Aspirin, Codeine Phosphate, Phenobarbital 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:
Where Fo-ti and Aspirin, Codeine Phosphate, Phenobarbital 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.
#211 of 1,452 supplements looked up here in the last 7 days
#280 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 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.
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.
No drugs match “”.
1,256 interactions
- Diclofenac Sodium ›
- Diltiazem ›
- Theophylline ›
- Nifedipine ›
- Ibuprofen ›
- Aspirin ›
- Hydrocortisone ›
- Insulin (rdna) ›
- Naproxen ›
- Doxycycline ›
- Erythromycin ›
- Estradiol ›
- Minocycline ›
- Propranolol ›
- Tetracycline ›
- Lidocaine ›
- Amoxicillin ›
- Hydrochlorothiazide ›
- Norethindrone ›
- Testosterone ›
- Verapamil ›
- Fenofibrate ›
- Levonorgestrel ›
- Prednisone ›
- Quinidine ›
- Cyclosporine ›
- Dexamethasone ›
- Glyburide ›
- Insulin (pork) ›
- Methyltestosterone ›
- Triazolam ›
- Zopiclone ›
- Bupropion ›
- Ciprofloxacin ›
- Colchicine ›
- Fentanyl ›
- Flurbiprofen ›
- Isotretinoin ›
- Orphenadrine ›
- Oxybutynin ›
- Oxycodone ›
- Phenytoin ›
- Prednisolone ›
- Tacrolimus ›
- Temazepam ›
- Allopurinol ›
- Budesonide ›
- Carbamazepine ›
- Clindamycin ›
- Dextromethorphan ›
- Diclofenac Potassium ›
- Dipyridamole ›
- Doxorubicin ›
- Fluticasone ›
- Formoterol ›
- Indomethacin ›
- Insulin (human) ›
- Miconazole ›
- Morphine Sulfate ›
- Trimipramine ›
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
We also checked Fo-ti against these medications and found no known interaction in our sources. Open any page to confirm.
- Levothyroxine ›
- Methylphenidate ›
- Ivermectin ›
- Escitalopram ›
- Docusate ›
- Valacyclovir ›
- Hydroxyurea ›
- Sumatriptan ›
- Lisinopril ›
- Acyclovir ›
- Lamotrigine ›
- Gabapentin ›
- Pregabalin ›
- Azithromycin ›
- Methylene Blue ›
- Levothyroxine, Liothyronine ›
- Cyclopentolate ›
- Candesartan Cilexetil ›
- Cephalexin ›
- Roxithromycin ›
- Acetaminophen, Dextromethorphan, Doxylamine ›
- Pegunigalsidase Alfa-iwxj ›
- Daptomycin ›
- Hexobarbitone ›
- Levothyroxine Sodium ›
- Dexmethylphenidate ›
- Levetiracetam ›
- Factor 7a ›
- Thyroid Hormone ›
- Carbidopa, Levodopa ›
- Mitomycin ›
- Minoxidil ›
- Levodopa ›
- Ezetimibe ›
- Cefaclor ›
- Phentermine, Topiramate ›
- Phenylephrine ›
- Vancomycin ›
- Hethylphenidate Hcl ›
- Dirithromycin ›
- Bentoquatam ›
- Pentobarbitone ›
- Procainamide ›
- Hydroxychloroquine ›
- Azelaic Acid ›
- Triptorelin ›
- Dextrothyroxine ›
- Lomustine ›
- Pizotifen ›
- Tocainide ›
- Rocuronium ›
- Succimer ›
- Telmisartan ›
- Mitomycin C ›
- Lorazepam ›
- Desflurane ›
- Chenodiol ›
- Ranitidine ›
- Metronidazole ›
- Lithium Carbonate (prescription Drug) ›
Showing the 60 most looked-up of 1,573 medications checked with no known interaction — see the full Fo-ti 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
Aspirin, Codeine Phosphate, Phenobarbital Is Linked to Lower Levels of 9 Nutrients
Natural Medicines records Aspirin, Codeine Phosphate, Phenobarbital as a medicine that can lower these. This is not an interaction with Fo-ti — it is a separate effect of the medicine, and it is a reason some people are advised to supplement rather than to avoid one:
- ACETYL-L-CARNITINE›
- BIOTIN›
- CALCIUM›
- FOLIC ACID›
- L-CARNITINE›
- PROPIONYL-L-CARNITINE›
- RIBOFLAVIN›
- VITAMIN B12›
- VITAMIN C›
Read the full Aspirin, Codeine Phosphate, Phenobarbital 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 Fo-ti and Aspirin, Codeine Phosphate, Phenobarbital Together: Common Questions
Can you take Fo-ti with Aspirin, Codeine Phosphate, Phenobarbital?
Why are there 3 interactions listed for Fo-ti and Aspirin, Codeine Phosphate, Phenobarbital?
How serious is the Fo-ti and Aspirin, Codeine Phosphate, Phenobarbital 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.