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Glycine Serum/Fasting Blood Draw (Mass Concentration)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of glycine, an amino acid, in your blood. Glycine plays a role in protein synthesis, metabolism, and nerve function.

Quick summary

["Understanding your glycine levels may help assess metabolic health or identify potential deficiencies."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
47638-2
Short code
Glycine SFr DBS
Synonyms
Glycine SFr DBS
Category
glucose
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like fatigue, muscle weakness, or neurological issues that could be linked to glycine metabolism. It may also be part of a broader evaluation for conditions like glycine encephalopathy or certain genetic disorders.

What to Expect Before the Test

You’ll typically have a simple blood draw from a vein in your arm. If fasting is required, follow your provider’s instructions carefully. Avoid alcohol or certain medications that could affect results.

What the Results Mean

Results are compared to a general reference range for glycine in blood. Abnormal levels might indicate metabolic issues or other health concerns that need further investigation.

Common Conditions Monitored

High or low glycine levels can be associated with conditions like glycine transporter disorders, certain metabolic syndromes, or rare genetic disorders affecting amino acid metabolism.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Glycine Level

Frequently asked questions

How is glycine tested in the lab?
Glycine is measured using an enzymatic method, which detects its concentration in your serum or plasma. The test is usually performed on a blood sample drawn from a vein.
What are typical reference ranges for glycine?
Reference ranges vary by lab and may not be widely published due to the rarity of glycine-specific testing. Your results will be interpreted in the context of your clinical symptoms and overall health.
Can lifestyle changes affect glycine levels?
Dietary factors, such as protein intake, may influence glycine levels, but direct dietary adjustments for this test are not standard. Follow your healthcare provider’s guidance for any recommended changes.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy