Alpha-gpc + Methscopolamine, Pseudoephedrine
Methscopolamine, Pseudoephedrine brand name: Allerx D.
Alpha-gpc has a minor interaction with Methscopolamine, Pseudoephedrine. Theoretically, alpha-GPC might decrease the effects of scopolamine.
Read the full interaction reportAlpha-gpc and Methscopolamine, Pseudoephedrine
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.
Here is the simple version. The methscopolamine part of Allerx D is an anticholinergic, meaning it works by quieting the chemical messenger acetylcholine to help dry up a runny nose and reduce secretions. Alpha-GPC does the opposite. It feeds your body more choline, the raw material used to make acetylcholine. So in theory, alpha-GPC could nudge against methscopolamine and slightly soften its drying effect.
I want to keep this in perspective, though. The evidence comes from a small study using injected scopolamine, not this combination pill, so the real-world effect is uncertain and rated minor. You likely would not notice much. Still, it is worth mentioning to your pharmacist or doctor before you pair them, just so they know what you are taking.
- 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 Methscopolamine, Pseudoephedrine 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 Methscopolamine, Pseudoephedrine
This page covers Alpha-gpc only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methscopolamine, Pseudoephedrine page lists 94 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 Peyote (major).
By severity: 8 major · 70 moderate · 16 minor.
From our pharmacist’s overview on the Methscopolamine, Pseudoephedrine page
“Allerx D combines pseudoephedrine, a stimulant decongestant, with methscopolamine, a drying anticholinergic, and its supplement list deserves genuine respect. Of the 94 ingredients on file, 8 carry a major rating; start there.”
Reviewed by 2 · Jul 18, 2026
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 Methscopolamine, Pseudoephedrine 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 Methscopolamine, 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.
#146 of 1,452 supplements looked up here in the last 7 days
#2,033 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 ›
- Dextromethorphan, Methscopolamine, Phenylephrine ›
- Methscopolamine, Mivacurium, Phenylephrine ›
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 Methscopolamine, Pseudoephedrine Together: Common Questions
Can you take Alpha-gpc with Methscopolamine, Pseudoephedrine?
How serious is the Alpha-gpc and Methscopolamine, Pseudoephedrine 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.