Drug & supplement interaction

Dimethylglycine (dmg) + Phenytoin

Phenytoin brand names: Dilantin Kapseals, Dilantin, Di-Phen, Dilantin Infatabs, Phenytek, and others.

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

We found no known interaction between Dimethylglycine (dmg) and Phenytoin 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.

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Interaction report

Dimethylglycine (dmg) and Phenytoin

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 Phenytoin and Dimethylglycine (dmg) 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Dimethylglycine (dmg) at all — not against Phenytoin, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Dimethylglycine (dmg) safety at a glance

Dimethylglycine (d... overall Use caution Appears generally well tolerated short-term, but high-quality long-term safety data are limited.
Pregnancy Avoid Not enough safety information; best to avoid during pregnancy.
Breastfeeding Avoid No reliable safety data, so avoid while breastfeeding.

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

Still wondering about combining Phenytoin and Dimethylglycine (dmg)? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Phenytoin’s Own FDA Label Lists

This is not an interaction — none of it involves Dimethylglycine (dmg). These are the most notable effects listed in the ADVERSE REACTIONS section of Phenytoin’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 10 of them are worth acting on rather than waiting out — marked below.

  • A change in thyroid levels Worth acting on
  • Unsteadiness Worth acting on
  • High blood sugar Worth acting on
  • Confusion Worth acting on
  • A severe skin reaction Worth acting on
  • Seizures Worth acting on
  • A low platelet count Worth acting on
  • Anemia Worth acting on
  • A severe allergic reaction Worth acting on
  • Hives Worth acting on

Showing the 10 most notable of 25 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Phenytoin. Read the label on DailyMed › Dimethylglycine (dmg)’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Dimethylglycine (dmg) side to compare — that is a limit of the record, not a statement that Dimethylglycine (dmg) has no side effects.

From our Q&A

Questions About Dimethylglycine (dmg) or Phenytoin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Dimethylglycine (dmg) or Phenytoin, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Phenytoin

This page covers Dimethylglycine (dmg) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Phenytoin page lists 224 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: 9 major · 187 moderate · 28 minor.

From our pharmacist’s overview on the Phenytoin page

“Phenytoin (Dilantin) is a seizure medicine with a narrow therapeutic index, meaning small changes in its blood level can bring seizures back or tip over into toxicity, so I treat its supplement list with real seriousness. The biggest group, 78 ingredients, piles on sedation, and alcohol, kava, and GHB all rate major for exactly that re…”

Reviewed by 2 · Jul 18, 2026

Open the Phenytoin interaction page

How much people look this up

Where Dimethylglycine (dmg) and Phenytoin 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 Dimethylglycine (dmg)
Steady interest

#1,412 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Phenytoin
Steady interest

#1,453 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. Dimethylglycine (dmg) is not yet covered by that licensed database, so its write-up cites publicly available medical sources directly (see the references below).
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Dimethylglycine (dmg) reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Dimethylglycine (dmg) and Phenytoin records this page draws on were last updated June 22, 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 Dimethylglycine (dmg)

What is Dimethylglycine (dmg)?

  • Athletic performance and energy
  • Autism spectrum support
  • Immune support
  • Seizure disorders
  • General wellness and detox support

Dimethylglycine (DMG) is a substance made naturally in the body and found in small amounts in foods. It is marketed for energy, athletic performance, autism, and immune support, but solid human evidence for most of these uses is limited. It appears generally well tolerated in short-term use, but talk with your pharmacist or doctor before trying it.

Not applicable (a naturally occurring amino acid derivative) · Tablets, capsules, chewable tablets, sublingual tablets, powder

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

Dimethylglycine (dmg): dosing

There is no officially established or standardized dose of DMG. Products vary widely in strength and in the directions they give.The safest approach is to follow the dosing instructions on the product label and not exceed them. If you do not notice a clear benefit, there is no reason to keep taking it.

From our Dimethylglycine (dmg) monograph — the full record covers uses, side effects and every documented interaction.

Read the full Dimethylglycine (dmg) monograph & all interactions
Medication

About Phenytoin

What Is Phenytoin Used For?

Brand names: Dilantin Kapseals, Dilantin, Di-Phen, Dilantin Infatabs, Phenytek, Dilantin injection

Phenytoin is used to treat and prevent seizures. The specific types covered depend on the formulation. Oral extended-release capsules (including Phenytek), chewable tablets (including Dilantin Infatabs and Phenytoin Infatabs), and oral suspension (including Dilantin-125) are used for tonic-clonic (grand mal) and psychomotor (temporal lobe) seizures; most oral forms also cover prevention and treatment of seizures occurring during or after neurosurgery. Chewable tablets and some capsule formulations also cover complex partial seizures.

Parenteral (injectable) phenytoin sodium is used for generalized tonic-clonic status epilepticus (a prolonged, life-threatening seizure emergency) and for prevention and treatment of seizures during neurosurgery. The IV form can also substitute short-term for oral phenytoin when a patient cannot take it by mouth.

Most-Reported Side Effects for Phenytoin

From FAERS, the FDA’s public side-effect reporting system (40,278 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Convulsion 3,522 reports
Seizure 3,095 reports
Toxicity to various agents 1,888 reports
Fall 1,604 reports
Dizziness 1,539 reports
See full Phenytoin drug information
Keep checking

Other Drugs & Dimethylglycine (dmg)

Browse every other medication we’ve checked against Dimethylglycine (dmg) — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

We also checked Dimethylglycine (dmg) against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Dimethylglycine (dmg) list.

See the full Dimethylglycine (dmg) interactions page
See every supplement checked against Phenytoin, ranked by severity
Evidence & sources

Dimethylglycine (dmg) References

The 2 sources that drive our Dimethylglycine (dmg) monograph — publicly available pages from reputable medical and government organizations. Every link was verified to work before publishing. Dimethylglycine (dmg) is not covered by the licensed Natural Medicines interaction database, so its page cites these public sources directly.

  1. Dietary Supplements: What You Need to Know — NIH Office of Dietary Supplements Source
  2. Using Dietary Supplements Wisely — NIH NCCIH Source

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 Dimethylglycine (dmg) and Phenytoin Together: Common Questions

Is it safe to take Dimethylglycine (dmg) with Phenytoin?
We do not list a known interaction between Dimethylglycine (dmg) and Phenytoin. 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.
Does Phenytoin interact with any supplements?
Yes. Phenytoin has documented interactions with 224 supplements in our database — Dimethylglycine (dmg) is not one of them. The Phenytoin 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

Dimethylglycine (dmg) monograph Uses, safety profile, and every drug interaction in one place Phenytoin drug information The full plain-English guide to this medication Phenytoin supplement interactions Every supplement checked against Phenytoin, 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 2 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Phenytoin and Dimethylglycine (dmg)?

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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.