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Dietary supplement

Glycine Ingredients & Drug Interactions

by Source Naturals

Glycine label
See full label image
Capsule Category: Amino Acid/protein
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 Glycine 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

Glycine is a dietary supplement by Source Naturals with 1 active ingredient. 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 Glycine by Source Naturals

Ask about any prescription or over-the-counter medication and we check it for interactions with Glycine by Source Naturals — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Glycine by Source Naturals

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 30, 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 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: glycine, a naturally occurring amino acid. Glycine plays roles in protein synthesis, nervous system function, and other metabolic processes in your body.

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).

The evidence for glycine is limited and mixed. It's rated possibly effective for schizophrenia, though the data overall are lean.

For several other conditions—including 3-phosphoglycerate dehydrogenase (3-PGDH) deficiency, ADHD, benign prostatic hyperplasia (BPH), and cystic fibrosis—we don't have enough reliable evidence to say whether it works or not.

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. Side effects have been rare.

Mild sedation, irritability, insomnia, fatigue, memory impairment, headache, and sensory changes have been reported occasionally, though it's unclear whether glycine is truly responsible. Soft stools, nausea, vomiting, upper abdominal discomfort, and dry mouth have also been reported rarely and tend to resolve quickly if you stop taking it.

There isn't enough reliable safety data for use during pregnancy or breastfeeding. If you're pregnant, planning to become pregnant, or breastfeeding, talk with your doctor or pharmacist before taking this product.

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), an antipsychotic for schizophrenia, check with your doctor or pharmacist before starting glycine—it may reduce the medication's effectiveness. No other medication interactions are documented in our data for the ingredients we could check.

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.

Glycine may be worth considering if you're interested in it for schizophrenia and your doctor approves—though the evidence is modest. If you take clozapine for schizophrenia, check with your doctor before adding this supplement, since it may interfere with how well the medication works.

For any other condition, the evidence isn't established. Talk it over with your doctor or pharmacist first.

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

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Apr 25, 2017.

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 Glycine, straight from the product label.

Brand Source Naturals
Barcode (UPC) 021078016045
Net contents 100 Capsule(s)
Market status On market
Date entered into DSLD Apr 25, 2017
DSLD ID 72838
Product type Amino Acid/protein
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy Free, Sugar 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 Glycine by Source Naturals, 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:
2 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
Servings per container
50
UPC/BARCODE
021078016045
IngredientAmount% DV
Calories5 Calorie(s)--
Glycine1 Gram(s)--

Other ingredients: Gelatin, Microcrystalline Cellulose, Silica, Magnesium Stearate

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.
FDA Statement of Identity

Dietary Supplement

General Statements

500 mg

Glycine is a non-essential amino acid that has one of the simplest structures of all the amino acids. Glycine is found in proteins of all life forms, and is important in the synthesis of proteins as well as adenosine triphosphate (ATP).

Seals/Symbols

Non GMO Validated

Formulation

Non GMO Validated

Hypoallergenic: contains no yeast, dairy, egg, gluten, corn, soy or wheat.

Hypoallergenic: contains no yeast, dairy, egg, gluten, corn, soy or wheat. Contains no sugar, starch, salt, preservatives, or artificial color, flavor or fragrance

Suggested/Recommended/Usage/Directions

Suggested Use: 2 capsules 1 to 2 times daily.

Precautions

Caution: If you are pregnant, may become pregnant, or breastfeeding, consult your health care professional before using this product.

If you have kidney or liver disease or are anuric, consult your health care professional before using this product.

Do not use if either tamper-evident seal is broken or missing.

Keep out of the reach of children.

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

General

SN1604 REV H151

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

See for yourself

Glycine by Source Naturals label

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

Glycine 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 Glycine by Source Naturals

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size2 Capsule(s) Dosage formCapsule Servings per container50 Amounts shown are per serving.

Glycine

Interacts with
1 drug
1 Gram(s) 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

Other (inactive) ingredients: Gelatin, Microcrystalline Cellulose, Silica, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Glycine by Source Naturals Drug Interactions

Want to check YOUR meds against Glycine?

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 Glycine interact with 1 drug. Click any drug to see the details.

1 of the 1 ingredient in Glycine interact with drugs. Each result below shows which ingredient is responsible. Glycine

Each ingredient & the kinds of drugs it affects

For each ingredient in Glycine 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 Glycine, from the product label.

Source Naturals

Name
Source Naturals, Inc.
Street Address
P. O. Box 2118
City
Santa Cruz
State
CA
ZipCode
95062
Web Address
www.sourcenaturals.com
Pharmacist Counseling Corner

Glycine by Source Naturals: Common Questions

Does Glycine by Source Naturals interact with any medications?
Yes. Based on its ingredients, Glycine 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?
Glycine contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism 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.
What is glycine, and what does it do in the body?
Glycine is an amino acid—one of the building blocks your body uses to make proteins and carry out many metabolic functions, including nervous system activity. It's naturally present in your diet, especially in protein-rich foods.
Can I take this during pregnancy or while breastfeeding?
We don't have enough reliable safety data for either pregnancy or breastfeeding. Talk with your doctor or pharmacist about whether it's right for you in these situations—they can weigh any potential benefits against what we know and don't know.
Does glycine actually work for schizophrenia?
It's rated possibly effective based on available evidence, but the data are modest. If you're interested in it as part of your schizophrenia treatment, discuss it with your doctor rather than using it on your own.
What side effects might I notice?
Mild sedation, soft stools, nausea, or memory problems have been reported rarely and tend to go away quickly if you stop taking it. Other symptoms like irritability, insomnia, or headache have also been reported, though it's unclear if glycine causes them.
Why does the product say to avoid it unless my doctor approves?
Because long-term safety data are limited, we don't have a complete picture of how safe it is over weeks or months of regular use. That's why it's wise to get your doctor's or pharmacist's okay before starting.

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.

Glycine label
Go deeper

The Full Monographs Behind Glycine’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

Glycine'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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