Drug & supplement interaction

Alpha-gpc + Loperamide, Simethicone

Loperamide, Simethicone brand name: Imodium Advanced.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Alpha-gpc and Loperamide, Simethicone in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Loperamide, Simethicone states a food rule worth keeping to.

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Interaction report

Alpha-gpc and Loperamide, Simethicone

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Loperamide, Simethicone and Alpha-gpc in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Alpha-gpc safety at a glance

Alpha-gpc overall Use caution Generally well tolerated in studies, but long-term safety is not fully established.
Pregnancy Avoid Not enough safety information; avoid unless directed by your doctor.
Breastfeeding Avoid Not enough safety information; avoid unless directed by your doctor.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Loperamide, Simethicone and Alpha-gpc? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Loperamide, Simethicone

Interactions in our licensed database are recorded against drug classes, not just single drug names. Loperamide, Simethicone is filed under 3 classifications — anticholinergic drugs, p-glycoprotein substrates, oral drugs. Alpha-gpc has documented interactions with 1 drug class — the most serious being scopolamine (transderm scop) (minor) — and none of Loperamide, Simethicone’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Alpha-gpc Does Interact With Other Medications

Alpha-gpc has 16 minor known drug interactions in our database — Loperamide, Simethicone isn’t one of them. If you take anything else, check it against the full list below.

Minor 16 No known interaction 2,814 (incl. Loperamide, Simethicone)
Taking anything else?

Check Another of Your Medications Against Alpha-gpc

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

What to actually watch for

What Alpha-gpc Itself Has Been Linked To

This is not an interaction — nothing below involves Loperamide, Simethicone. It is the side-effect record for Alpha-gpc on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Alpha-gpc, this list is the first place to look. One entry is worth acting on rather than waiting out — marked below.

  • Fainting / Confusion Worth acting on Additional detail

    “Orally, alpha-GPC has been rarely associated with dizziness, excitation, headache, and insomnia. Alpha-GPC use for at least 2 months has also been associated with an elevated risk of stroke when compared with non-users or those who used alpha-GPC for less than 2 months.

    Intramuscularly, alpha-GPC has been rarely associated with confusion, excitation, fainting, headache, and insomnia.”

    Alpha-gpc · Natural Medicines adverse-effect record, reported in cluster headache.

    2 sources cited
    1. 12102. Barbagallo Sangiorgi G, Barbagallo M, Giordano M, et al. Alpha-glycerophosphocholine in the mental recovery of cerebral ischemic attacks: An Italian multicenter clinical trial. Ann N Y Acad Sci 1994;717:253-69. PubMed
    2. 108883. Lee G, Choi S, Chang J, et al. Association of L-a glycerylphosphorylcholine with subsequent stroke risk after 10 Years. JAMA Netw Open 2021;4(11):e2136008.
  • Heartburn / Diarrhea / Vomiting / Nausea Additional detail

    “Orally, alpha-GPC has been rarely associated with diarrhea, heartburn, nausea, and vomiting.

    Intramuscularly, alpha-GPC has been rarely associated with diarrhea, heartburn, nausea, and vomiting.”

    Alpha-gpc · Natural Medicines adverse-effect record, reported in diarrhea.

    1 source cited
    1. 12102. Barbagallo Sangiorgi G, Barbagallo M, Giordano M, et al. Alpha-glycerophosphocholine in the mental recovery of cerebral ischemic attacks: An Italian multicenter clinical trial. Ann N Y Acad Sci 1994;717:253-69. PubMed
  • Trouble sleeping / Dizziness / Headache Additional detail

    Recorded for Alpha-gpc in the same Natural Medicines adverse-effect record shown under Fainting / Confusion above.

  • A skin rash Additional detail

    “Orally, some patients can experience skin rash. Intramuscularly, alpha-GPC can cause erythema at the injection site.”

    Alpha-gpc · Natural Medicines adverse-effect record, reported in erythema.

    2 sources cited
    1. 12102. Barbagallo Sangiorgi G, Barbagallo M, Giordano M, et al. Alpha-glycerophosphocholine in the mental recovery of cerebral ischemic attacks: An Italian multicenter clinical trial. Ann N Y Acad Sci 1994;717:253-69. PubMed
    2. 12101. Di Perri R, Coppola G, Ambrosio LA, et al. A multicentre trial to the evaluate the efficacy and tolerability of alpha-glycerylphosphorylcholine versus cytosine diphosphocholine in patients with vascular dementia. J Int Med Res 1991;19:330-41.

Everything above comes from the Natural Medicines adverse-effect record for Alpha-gpc — expand a row for the licensed statement it rests on. We haven’t matched Loperamide, Simethicone to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Loperamide, Simethicone.

How to take them

Some Loperamide, Simethicone Products Have a Food Rule — Alpha-gpc Should Not Break It

At least one FDA label for a product containing Loperamide, Simethicone says to take it on an empty stomach. Most supplements — Alpha-gpc included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Loperamide, Simethicone on its own and move Alpha-gpc to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Loperamide, Simethicone products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

Directions drink plenty of clear fluids to help prevent dehydration caused by diarrhea take only on an empty stomach (1 hour before or 2 hours after a meal) take with a full (8 oz.) glass of water find right dose on chart below.

From the Dosage and Administration section of the FDA label we read for Loperamide, Simethicone — where that label names a specific product, the instruction is that product's.

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Everything else you take

See Every Supplement That Interacts With Loperamide, Simethicone

This page covers Alpha-gpc only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Loperamide, Simethicone page lists 82 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Henbane (major), Scopolia (major), St. John's Wort (major) and Angel's Trumpet (moderate).

By severity: 4 major · 59 moderate · 19 minor.

From our pharmacist’s overview on the Loperamide, Simethicone page

“Imodium Advanced combines loperamide, an anti-diarrheal opioid that normally stays out of the brain thanks to a transporter called P-glycoprotein, with simethicone for gas, and I treat its interaction list with more respect than most over-the-counter medicines warrant. Thirty-seven of the 82 interacting ingredients on file affect that…”

Reviewed by 2 · Jul 18, 2026

Open the Loperamide, Simethicone interaction page

One more smart check

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. Even though Alpha-gpc itself has no known interaction with Loperamide, Simethicone, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Alpha-gpc and Loperamide, Simethicone 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 Alpha-gpc
Top 25%

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

29 days ago today
Medication Loperamide, Simethicone
Top half

#779 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Alpha-gpc reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Alpha-gpc and Loperamide, Simethicone records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Alpha-gpc

What is Alpha-gpc?

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.

Synthesized compound; also found naturally in soy lecithin and small amounts in foods · Capsules, tablets, powder, liquid

An interaction check asks whether these two react with each other — it does not ask whether Alpha-gpc is a good idea for someone in your situation. Here is what our Alpha-gpc record says about it on its own.

Alpha-gpc: dosing

There is no official, standardized dose of Alpha-GPC for any condition. Doses used in research have varied depending on the purpose and the people studied.The safest approach is to follow the directions on the product label and not exceed them.

From our Alpha-gpc monograph — the full record covers uses, side effects and every documented interaction.

Read the full Alpha-gpc monograph & all interactions
Keep checking

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.

0Major
0Moderate
16Minor
2,813No known interaction
16 Minor 2,813 No interaction
Minor

16 interactions

No interaction 2,813 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.

Showing the 60 most looked-up of 2,813 medications checked with no known interaction — see the full Alpha-gpc list.

See the full Alpha-gpc interactions page
See every supplement checked against Loperamide, Simethicone, ranked by severity
Evidence & sources

Alpha-gpc References

The 4 references that drive our Alpha-gpc monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Di Perri R, Coppola G, Ambrosio LA, et al. A multicentre trial to the evaluate the efficacy and tolerability of alpha-glycerylphosphorylcholine versus cytosine diphosphocholine in patients with vascular dementia. J Int Med Res 1991;19:330-41.
  2. Barbagallo Sangiorgi G, Barbagallo M, Giordano M, et al. Alpha-glycerophosphocholine in the mental recovery of cerebral ischemic attacks: An Italian multicenter clinical trial. Ann N Y Acad Sci 1994;717:253-69. PubMed
  3. 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.
  4. Lee G, Choi S, Chang J, et al. Association of L-a glycerylphosphorylcholine with subsequent stroke risk after 10 Years. JAMA Netw Open 2021;4(11):e2136008.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Alpha-gpc and Loperamide, Simethicone Together: Common Questions

Is it safe to take Alpha-gpc with Loperamide, Simethicone?
We do not list a known interaction between Alpha-gpc and Loperamide, Simethicone. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Should I take Alpha-gpc and Loperamide, Simethicone at the same time of day?
At least one FDA label for a product containing Loperamide, Simethicone says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Loperamide, Simethicone on its own and move Alpha-gpc to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.
How was the Alpha-gpc and Loperamide, Simethicone combination checked?
Interactions in our licensed database are recorded against drug classes. Loperamide, Simethicone is filed under 3 classifications, and Alpha-gpc has documented interactions with 1 drug class — none of Loperamide, Simethicone's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Alpha-gpc interact with any other medications?
Yes. Alpha-gpc has 16 documented drug interactions in our database — Loperamide, Simethicone is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Loperamide, Simethicone interact with any supplements?
Yes. Loperamide, Simethicone has documented interactions with 82 supplements in our database — Alpha-gpc is not one of them. The Loperamide, Simethicone interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Alpha-gpc monograph Uses, safety profile, and every drug interaction in one place Loperamide, Simethicone supplement interactions Every supplement checked against Loperamide, Simethicone, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 4 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Loperamide, Simethicone and Alpha-gpc?

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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.