Drug & supplement interaction

Alpha-gpc + Methsuximide

Methsuximide brand name: Celontin.

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 Methsuximide 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 two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Alpha-gpc and Methsuximide

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 Methsuximide 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 Methsuximide and Alpha-gpc? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Methsuximide

Interactions in our licensed database are recorded against drug classes, not just single drug names. Methsuximide is filed under 3 classifications — anticonvulsants, cns depressants, oral drugs. Alpha-gpc has documented interactions with 1 drug class — the most serious being scopolamine (transderm scop) (minor) — and none of Methsuximide’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 — Methsuximide 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. Methsuximide)
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

No Interaction Found — But Data Suggests Alpha-gpc and Methsuximide May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • Confusion Worth acting on Additional detail

    Alpha-gpc

    “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.

    Methsuximide

    Listed in the ADVERSE REACTIONS section of the FDA label for Methsuximide. Read the label on DailyMed ›

  • Trouble sleeping / Dizziness / Headache reported in 7.2% of FDA reports for Methsuximide Additional detail

    Alpha-gpc

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

    Methsuximide

    Listed in the ADVERSE REACTIONS section of the FDA label for Methsuximide, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

  • Diarrhea / Vomiting / Nausea Additional detail

    Alpha-gpc

    “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

    Methsuximide

    Listed in the ADVERSE REACTIONS section of the FDA label for Methsuximide. Read the label on DailyMed ›

Reported for Alpha-gpc but not commonly for Methsuximide: heartburn, a skin rash and fainting.

Effects for Methsuximide come from the ADVERSE REACTIONS section of its FDA label; effects for Alpha-gpc come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 181 voluntary FDA FAERS reports for Methsuximide that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Everything else you take

See Every Supplement That Interacts With Methsuximide

This page covers Alpha-gpc only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methsuximide page lists 105 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), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Kava (major).

By severity: 7 major · 82 moderate · 16 minor.

From our pharmacist’s overview on the Methsuximide page

“Methsuximide (Celontin) treats absence seizures by quieting overactive brain signals, so anything else that slows the nervous system deserves genuine respect before you take it alongside. Of the 105 supplements and herbs on record, 78 add sedation on top of what the drug already does, and that group holds most of the 7 major-rated entr…”

Reviewed by 2 · Jul 18, 2026

Open the Methsuximide 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 Methsuximide, 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 Methsuximide 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%

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

29 days ago today
Medication Methsuximide
Steady interest

#2,402 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 Methsuximide 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
Medication

About Methsuximide

What Is Methsuximide Used For?

Brand name: Celontin

Methsuximide is used to control absence (petit mal) seizures — brief episodes of staring or lapses in consciousness — when other seizure medications have not worked. Both Celontin and the generic methsuximide capsules carry this indication.

It can also be used alongside other antiseizure medications when a person has absence seizures together with other types of epilepsy.

Most-Reported Side Effects for Methsuximide

From FAERS, the FDA’s public side-effect reporting system (181 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Seizure 21 reports
Convulsion 14 reports
Dizziness 13 reports
Somnolence 13 reports
Feeling abnormal 11 reports
See full Methsuximide drug information
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 Methsuximide, 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 Methsuximide Together: Common Questions

Is it safe to take Alpha-gpc with Methsuximide?
We do not list a known interaction between Alpha-gpc and Methsuximide. 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.
Do Alpha-gpc and Methsuximide have any of the same side effects?
Yes — our sources link each of them separately to 7 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Alpha-gpc and Methsuximide combination checked?
Interactions in our licensed database are recorded against drug classes. Methsuximide is filed under 3 classifications, and Alpha-gpc has documented interactions with 1 drug class — none of Methsuximide'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 — Methsuximide 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 Methsuximide interact with any supplements?
Yes. Methsuximide has documented interactions with 105 supplements in our database — Alpha-gpc is not one of them. The Methsuximide 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 Methsuximide drug information The full plain-English guide to this medication Methsuximide supplement interactions Every supplement checked against Methsuximide, 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 Methsuximide 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.