Alpha-gpc + Dextromethorphan, Methscopolamine, Phenylephrine
Dextromethorphan, Methscopolamine, Phenylephrine brand name: DA Chewable.
Alpha-gpc has a minor interaction with Dextromethorphan, Methscopolamine, Phenylephrine. Theoretically, alpha-GPC might decrease the effects of scopolamine.
Read the full interaction reportAlpha-gpc and Dextromethorphan, Methscopolamine, Phenylephrine
Here is the interaction we found between these two, with the evidence behind it.
SCOPOLAMINE (Transderm Scop)
A small clinical study shows that alpha-GPC can partially counteract the attention and memory impairment effects caused by scopolamine given intramuscularly. Whether alpha-GPC can decrease the beneficial anti-motion sickness effects of the scopolamine patch (Transderm Scop) is unclear.
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 your cold-and-cough combo that interacts here is the methscopolamine, which is a drying agent related to scopolamine. It works by blocking acetylcholine, the same brain messenger that Alpha-GPC helps your body build more of. So in theory these two are pulling in opposite directions, and Alpha-GPC could slightly blunt the methscopolamine's effects.
In real life this is rated a minor interaction, and the evidence is limited (a small study using injected scopolamine, not your oral product). You likely won't notice much. If anything, the drying or anti-runny-nose benefit might feel a touch weaker. The dextromethorphan and phenylephrine aren't really involved. Nothing alarming here, but check with your pharmacist before adding Alpha-GPC.
- Canal N, Franceschi M, Alberoni M, et al. Effect of L-alpha-glyceryl-phosphorylcholine on amnesia caused by scopolamine. Int J Clin Pharmacol Ther Toxicol 1991;29:103-7.
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.
Alpha-gpc Also Interacts With Other Medications
Alpha-gpc has 15 minor known drug interactions in our database — the Dextromethorphan, Methscopolamine, Phenylephrine one above is one of them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Alpha-gpc
We haven’t checked that one against Alpha-gpc yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Alpha-gpc. Pick one to open its full report.
See Every Supplement That Interacts With Dextromethorphan, Methscopolamine, Phenylephrine
This page covers Alpha-gpc only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Dextromethorphan, Methscopolamine, Phenylephrine page lists 220 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Activated Charcoal (major), Ephedra (major), Grapefruit (major), Henbane (major) and Lithium (major).
By severity: 10 major · 166 moderate · 44 minor.
From our pharmacist’s overview on the Dextromethorphan, Methscopolamine, Phenylephrine page
“Dextromethorphan with methscopolamine and phenylephrine (DA Chewable) packs a cough suppressant, a drying agent, and a decongestant into one tablet, which gives supplements several distinct ways to cause trouble, so I treat this as a list deserving real caution. Grapefruit can drive levels of the drug up by blocking its breakdown, St.”
Reviewed by 2 · Jul 18, 2026
Open the Dextromethorphan, Methscopolamine, Phenylephrine interaction page
Taking Alpha-gpc as Part of a Dietary Supplement Product? Check It for Interactions
We hold 1,138 real supplement products containing Alpha-gpc, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Alpha-gpc. Your product may carry other ingredients that interact with Dextromethorphan, Methscopolamine, Phenylephrine too, on top of Alpha-gpc — and those would not show on this page. Find your product and we’ll check every ingredient on its label:
Where Alpha-gpc and Dextromethorphan, Methscopolamine, 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.
#146 of 1,452 supplements looked up here in the last 7 days
#1,114 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 Alpha-gpc
What is Alpha-gpc?
- Memory and learning support
- Age-related cognitive decline
- Alzheimer's disease and dementia (under study)
- Athletic and physical performance
- Source of choline
Alpha-GPC is a choline-containing compound used mainly for memory, brain health, and as a choline source. There is some evidence it may help cognition in people with dementia, but evidence in healthy people is limited. Talk to your pharmacist or doctor before starting it, especially if you take other medicines or have a health condition.
Other Drugs & Alpha-gpc
Browse every other medication we’ve checked against Alpha-gpc — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
15 interactions
- Scopolamine ›
- Methscopolamine Bromide ›
- Chlorpheniramine, Methscopolamine, Phenylephrine ›
- Atropine, Chlorpheniramine, Hyoscyamine, Phenylephrine, Phenylpropanolamine, Scopolamine ›
- Atropine, Hyoscyamine, Scopolamine, Phenobarbital ›
- Chlorpheniramine, Methscopolamine, Pseudoephedrine ›
- Atropine, Hyoscyamine, Phenobarbital, Scopolamine ›
- Belladonna Alkaloids, Phenobarbital ›
- Atropine, Hyoscyamine, Scopolamine ›
- Barbital, Hyoscyamine, Scopolamine, Passiflora, Valeri ›
- Camphor, Hyoscyamine, Passif, Phenobarbital, Scopolamine, Valerian ›
- Chlorpheniramine, Methscopolamine ›
- Chlorpheniramine, Methscopolamine, Phenylpropanolamine ›
- Methscopolamine, Mivacurium, Phenylephrine ›
- Methscopolamine, Pseudoephedrine ›
No interaction 2,814 drugs checked — show the list
We also checked Alpha-gpc against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Warfarin ›
- Sertraline ›
- Testosterone ›
- Losartan Potassium ›
- Metoprolol ›
- Aspirin ›
- Ivermectin ›
- Rivaroxaban ›
- Rosuvastatin ›
- Escitalopram ›
- Tadalafil ›
- Acetaminophen ›
- Clopidogrel ›
- Valacyclovir ›
- Atorvastatin ›
- Docusate ›
- Hydroxyurea ›
- Abemaciclib ›
- Methamphetamine ›
- Ibuprofen ›
- Sumatriptan ›
- Semaglutide ›
- Tirzepatide ›
- Warfarin Sodium ›
- Prednisone ›
- Propranolol ›
- Lisdexamfetamine ›
- Acyclovir ›
- Bupropion ›
- Metformin ›
- Amoxicillin ›
- Lisinopril ›
- Bendamustine ›
- Amitriptyline ›
- Doxycycline ›
- Lamotrigine ›
- Fluoxetine ›
- Methotrexate ›
- Acetaminophen, Codeine ›
- Gabapentin ›
- Amphetamine ›
- Pregabalin ›
- Isotretinoin ›
- Dextroamphetamine ›
- Azithromycin ›
- Clonazepam ›
- Quetiapine ›
- Omeprazole ›
- Amlodipine Besylate ›
- Methylene Blue ›
- Duloxetine ›
- Letrozole ›
- Buspirone ›
- Citalopram ›
- Ciprofloxacin ›
- Naproxen ›
Showing the 60 most looked-up of 2,814 medications checked with no known interaction — see the full Alpha-gpc 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
Taking Alpha-gpc and Dextromethorphan, Methscopolamine, Phenylephrine Together: Common Questions
Can you take Alpha-gpc with Dextromethorphan, Methscopolamine, Phenylephrine?
How serious is the Alpha-gpc and Dextromethorphan, Methscopolamine, Phenylephrine interaction?
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