Interactions on record — worth a quick check against your medications. Based on 1 of 2 ingredients. Check your meds →
Dietary supplement

5-MTHF Quatrefolic Ingredients & Drug Interactions

by Metabolic Maintenance

5-MTHF Quatrefolic label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking 5-MTHF Quatrefolic against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

5-MTHF Quatrefolic is a dietary supplement by Metabolic Maintenance with 2 active ingredients. Its ingredients are commonly taken for sleep quality and insomnia, relaxation, cognitive function.Based on those ingredients, 1 medication has a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Glycine. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against 5-MTHF Quatrefolic by Metabolic Maintenance

Ask about any prescription or over-the-counter medication and we check it for interactions with 5-MTHF Quatrefolic by Metabolic Maintenance — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of 5-MTHF Quatrefolic by Metabolic Maintenance

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 2 of its 2 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

This product has 2 active ingredients: glycine and L-methylfolate. Glycine is an amino acid; L-methylfolate is a form of folate (vitamin B9).

The capsule itself is vegetarian.

Does it work?

Moderate evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed

This product doesn't appear to be marketed for a specific use, so we graded Glycine's overall clinical evidence instead.

Moderate

Some clinical evidence supports Glycine for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredient's overall clinical evidence instead.
  • On file: Schizophrenia — rated "Possibly Effective" (Natural Medicines).

Glycine is possibly effective for schizophrenia, according to our data. For other uses listed — including 3-phosphoglycerate dehydrogenase deficiency, ADHD, benign prostatic hyperplasia, and cystic fibrosis — the evidence isn't established.

We hold no effectiveness rating for L-methylfolate.

The evidence, ingredient by ingredient Glycine

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Glycine is generally well tolerated at typical doses, but long-term safety data are limited. Mild side effects have been reported rarely and include mild sedation, irritability, insomnia, fatigue, memory problems, headache, sensory changes, soft stools, nausea, vomiting, upper GI discomfort, and dry mouth — most resolve quickly if you stop taking it.

Not enough reliable safety data exist during pregnancy, so it's best avoided unless your doctor approves. Similarly, safety data during breastfeeding are limited, so caution is advised.

We hold no pregnancy or breastfeeding data for L-Methylfolate.

Side effects, ingredient by ingredient Glycine

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Glycine.
  • The most serious interaction on file is rated Moderate.
  • For scale: 1 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

If you take clozapine (Clozaril) for schizophrenia, this product's glycine may decrease its effectiveness — check with your pharmacist or doctor before starting. We could not check L-Methylfolate for interactions, so mention all your medications when you discuss this supplement.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.

If you have schizophrenia and take clozapine, talk to your pharmacist or doctor before using this product — the glycine in it may interfere with your medication. For anyone else, check your exact medications against our interaction tool on this page, especially if you take any prescription drugs.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Aug 23, 2013.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about 5-MTHF Quatrefolic, straight from the product label.

Brand Metabolic Maintenance
Barcode (UPC) 838287005346
Net contents 60 Capsule(s); 10 mg
Market status On market
Date entered into DSLD Aug 23, 2013
DSLD ID 24715
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for 5-MTHF Quatrefolic by Metabolic Maintenance, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
UPC/BARCODE
838287005346
IngredientAmount% DV
Glycine210 mg--
L-Methylfolate10 mg2500%

Other ingredients: vegetarian capsule

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Brand IP Statement(s)

Quatrefolic(R), pure S isomer methylfolate glucosamine salt, has been proven to have greater stability, solubility and bioavailability than any other form of 5-MTHF.

Quatrefolic(R) is a registered trademark of Gnosis S.p.A.

Formulation

Gluten and Excipient-free.

Precautions

CAUTION: Pregnant or lactating women, or individuals taking prescription medications, consult your healthcare professional before taking this product.

Keep tightly closed in a cool, dry place out of the reach of children.

Storage

Keep tightly closed in a cool, dry place out of the reach of children.

General Statements

Manufactured in a GMP Compliant Facility

534001A EXP 3/14

ESSENTIALS

V.01

FDA Disclaimer Statement

These statements have not been evaluated by the FDA. These products are not intended to diagnose, treat, cure or prevent any diseases.

FDA Statement of Identity

DIETARY SUPPLEMENT

Suggested/Recommended/Usage/Directions

DIRECTIONS: Use only as directed by a healthcare professional.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

5-MTHF Quatrefolic by Metabolic Maintenance label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

5-MTHF Quatrefolic label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in 5-MTHF Quatrefolic by Metabolic Maintenance

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Glycine

Interacts with
1 drug
210 mg per serving

Glycine is a non-essential amino acid your body makes on its own and that also appears in protein-rich foods. It is most studied for improving sleep q...

Glycine monograph & interactions

L-Methylfolate

10 mg per serving Form: (6S)-5-Methyltetrahydrofolate, Glucosamine Salt

Other (inactive) ingredients: Vegetarian capsule. These complete the product’s ingredient list but are not active constituents.

Interaction report

5-MTHF Quatrefolic by Metabolic Maintenance Drug Interactions

Want to check YOUR meds against 5-MTHF Quatrefolic?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
1Drugs
1 Moderate

Ingredients driving the most interactions

Glycine 1

Individual Drug Interactions

The ingredients in 5-MTHF Quatrefolic interact with 1 drug. Click any drug to see the details.

1 of the 2 ingredients in 5-MTHF Quatrefolic interact with drugs. Each result below shows which ingredient is responsible. Glycine

Each ingredient & the kinds of drugs it affects

For each ingredient in 5-MTHF Quatrefolic with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Glycine1 drug type · 1 drug

Clozapine (Clozaril)

Theoretically, glycine might decrease the effectiveness of clozapine.
One small clinical study in patients with schizophrenia shows that adding glycine to clozapine therapy worsens symptoms of schizophrenia when compared with clozapine alone. The mechanism of this interaction is unclear.

Likelihood Probable Evidence B
Glycine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for 5-MTHF Quatrefolic, from the product label.

Metabolic Maintenance

See all Metabolic Maintenance products
Name
Metabolic Maintenance Products
Street Address
PO Box 940
City
Sisters
State
Oregon
ZipCode
97759
Web Address
www.metabolicmaintenance.com
Pharmacist Counseling Corner

5-MTHF Quatrefolic by Metabolic Maintenance: Common Questions

Does 5-MTHF Quatrefolic by Metabolic Maintenance interact with any medications?
Yes. Based on its ingredients, 5-MTHF Quatrefolic has a known interaction with 1 medication. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
5-MTHF Quatrefolic contains 2 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Can I take this if I'm pregnant or breastfeeding?
The glycine in this product doesn't have enough safety data for pregnancy — your doctor should approve it first. Breastfeeding safety data are also limited, so caution is advised. There's no pregnancy or breastfeeding information on file for L-methylfolate. Talk with your pharmacist or doctor about your specific situation.
What is L-methylfolate and why is it in this product?
L-methylfolate is a form of folate, which is vitamin B9. We don't hold effectiveness data on why it's included in this particular formula, so ask your pharmacist or the manufacturer about its intended role.
Will glycine make me tired?
Mild sedation has been reported rarely with glycine, and it stopped quickly once people discontinued it. Most people tolerate it well at typical doses, though long-term safety data are limited.
Is this safe to take long-term?
Glycine is generally well tolerated at typical doses, but long-term safety data are limited — meaning we don't have enough research on extended use. Check with your pharmacist or doctor if you're planning to use this for months at a time.

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

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

5-MTHF Quatrefolic label
Go deeper

The Full Monographs Behind 5-MTHF Quatrefolic’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Glycine

Interacts with 1 drug

Glycine is a non-essential amino acid your body makes on its own and that also appears in protein-rich foods. It is most studied for improving sleep quality, where early research is promisin...

Read the full Glycine monograph →
Sources

Sources & How We Checked

5-MTHF Quatrefolic's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 5 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Glycine 5 references
  1. Heresco-Levy U, Javitt DC, Ermilov M, et al. Efficacy of high-dose glycine in the treatment of enduring negative symptoms of schizophrenia. Arch Gen Psychiatry 1999;56:29-36.. PubMed
  2. Potkin SG, Jin Y, Bunney BG, Costa J, Gulasekaram B. Effect of clozapine and adjunctive high-dose glycine in treatment-resistant schizophrenia. Am J Psychiatry 1999;156:145-7.. PubMed
  3. Gusev EI, Skvortsova VI, Dambinova SA, et al. Neuroprotective effects of glycine for therapy of acute ischaemic stroke. Cerebrovasc Dis 2000;10:49-60. PubMed
  4. Inagawa K, Kawai N, Ono K, Sukegawa E, Tsubuku S, Takahashi M. Assessment of acute adverse effects of glycine ingestion at a high dose in human volunteers. Seikatsu Eisei. 2006; 50:27-32.
  5. Woods SW, Walsh BC, Hawkins KA, Miller TJ, Saksa JR, D'Souza DC, Pearlson GD, Javitt DC, McGlashan TH, Krystal JH. Glycine treatment of the risk syndrome for psychosis: report of two pilot studies. Eur Neuropsychopharmacol. 2013 Aug;23(8):931-40. PubMed

See these in context on the Glycine monograph →

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

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