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Dietary supplement

Glycine 250 mg Ingredients & Drug Interactions

by Kirkman

Capsule Category: Amino Acid/protein
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

Glycine 250 mg is a dietary supplement by Kirkman 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.

HelloPharmacist Scorecard of Glycine 250 mg by Kirkman

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

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 a single active ingredient: glycine, an amino acid your body produces naturally. Each capsule delivers 250 mg.

The capsule itself is made from cellulose, a plant-based inactive ingredient.

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 based on the evidence we hold. For other conditions — including 3-phosphoglycerate dehydrogenase (3-PGDH) deficiency, attention deficit-hyperactivity disorder (ADHD), benign prostatic hyperplasia (BPH), and cystic fibrosis — the evidence is insufficient to rate its effectiveness.

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, though long-term safety data are limited. Mild sedation, irritability, insomnia, fatigue, memory impairment, headache, and sensory impairment have been reported rarely; soft stools, nausea, vomiting, upper abdominal discomfort, and dry mouth have also occurred in some cases, though a clear link to glycine isn't always certain.

These symptoms tend to resolve quickly if you stop taking it. There isn't enough reliable safety data to know whether glycine is safe during pregnancy or breastfeeding.

Talk with your doctor or pharmacist before using this supplement if you're pregnant, planning to become pregnant, or breastfeeding — they can help you weigh the risks and benefits for your situation.

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, notify your doctor or pharmacist before taking this product — glycine may decrease its effectiveness and worsen schizophrenia symptoms. For all other medications, no interactions are documented in our data for glycine, but that does not guarantee none exist; use the interaction checker on this page with your complete medication list to be sure.

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 is a naturally occurring amino acid that shows some promise for schizophrenia, though evidence for other uses is incomplete. The most important thing to know is that it may reduce how well clozapine works — if you take that medication, check with your doctor or pharmacist first.

If you're pregnant, breastfeeding, or taking any other prescription drugs, have that same conversation with your healthcare provider before starting.

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 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 Glycine 250 mg, straight from the product label.

Brand Kirkman
Net contents 200 Capsule(s)
Market status On market
Date entered into DSLD Aug 23, 2013
DSLD ID 24591
Product type Amino Acid/protein
Supplement form Capsule
Dietary claims / uses All Other
Intended target group(s) Adult (18 - 50 Years), No Allergies, 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 250 mg by Kirkman, 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:
2 Capsule(s)
Servings per container
200
IngredientAmount% DV
Glycine250 mg--

Other ingredients: Cellulose, Plant

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.
Suggested/Recommended/Usage/Directions

SUGGESTED USE: 1-2 capsules daily or as directed by a physician.

Formula

HYPOALLERGENIC

Formulation

FREE OF: Sugar, starch, soy, wheat, casein, gluten, milk, corn, preservatives, yeast, gelatin, flavorings, colorings, fish, peanuts or tree nuts.

CASEIN & GLUTEN FREE

Precautions

KEEP OUT OF THE REACH OF CHILDREN.

General Statements

Best Used by: April 2013

Country of Origin USA

(503)694-1600

FDA Statement of Identity

Dietary Supplement

General

091/200

Storage

IMPORTANT: STORE IN A COOL DRY PLACE AND TIGHTLY CAPPED.

See for yourself

Glycine 250 mg by Kirkman label

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

What’s inside

The Ingredients in Glycine 250 mg by Kirkman

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

Serving size1 Capsule(s) Dosage formCapsule Servings per container200 Amounts shown are per serving.

Glycine

Interacts with
1 drug
250 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

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

Interaction report

Glycine 250 mg by Kirkman Drug Interactions

Want to check YOUR meds against Glycine 250 mg?

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

Each ingredient & the kinds of drugs it affects

For each ingredient in Glycine 250 mg 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
The maker

Brand information

Manufacturer and brand details for Glycine 250 mg, from the product label.

Kirkman

See all Kirkman products
Name
Kirkman
City
Lake Oswego
State
OR
ZipCode
97035
Phone Number
(800) 245-8282
Web Address
www.kirkmangroup.com
Pharmacist Counseling Corner

Glycine 250 mg by Kirkman: Common Questions

Does Glycine 250 mg by Kirkman interact with any medications?
Yes. Based on its ingredients, Glycine 250 mg 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 250 mg 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 — a building block — that your body makes naturally. It plays roles in protein synthesis and may affect brain chemistry. In this supplement, it's provided in concentrated form as a 250 mg capsule per dose.
Will this help my ADHD?
The evidence available to us is insufficient to rate glycine's effectiveness for ADHD, so we can't say whether it will or won't help. Talk with your doctor about whether a trial might be worth considering and what to watch for.
Can I take this while pregnant or breastfeeding?
There isn't enough reliable safety data to know either way. It's best to talk with your doctor or pharmacist before taking it during pregnancy or while breastfeeding — they can give you personalized advice based on your situation.
What side effects might I notice?
Mild sedation, irritability, insomnia, headache, nausea, vomiting, and soft stools have been reported rarely. These effects tend to clear up quickly if you stop the supplement. If side effects persist or concern you, talk with your pharmacist.
Is this safe to take long-term?
Glycine is generally well tolerated at typical doses, but long-term safety data are limited. Before taking this supplement for an extended period, discuss it with your doctor or pharmacist — they can help you decide whether the potential benefits outweigh the unknowns.

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

Not sure if Glycine 250 mg is safe with your meds?

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Ask a pharmacist

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 250 mg label
Go deeper

The Full Monographs Behind Glycine 250 mg’s Ingredients

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

Sources

Sources & How We Checked

Glycine 250 mg'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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