Skip to content

Free Threonine in Hair (24-Hour Fluid)

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

This test measures the amount of free threonine, an essential amino acid, in a 24-hour fluid sample collected from hair follicles. It may be used to assess amino acid metabolism or metabolic disorders.

Quick summary

["This test helps evaluate amino acid levels in your body, potentially identifying metabolic or genetic conditions."]

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

Key facts at a glance

LOINC
47785-1
Short code
Threonine SFr Hair
Synonyms
Threonine SFr Hair
Category
chemistry
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 unusual fatigue, muscle weakness, or unexplained metabolic issues. It could also be part of a broader evaluation for inherited metabolic disorders or amino acid imbalances.

What to Expect Before the Test

No special preparation is typically needed. You’ll collect a small sample of fluid from your hair follicles over 24 hours, following instructions provided by your lab or healthcare team.

What the Results Mean

Results help determine if your body is processing amino acids correctly. Abnormal levels might suggest conditions like aminoaciduria (excess amino acids in urine) or other metabolic disorders.

Common Conditions Monitored

This test may be used alongside other evaluations to diagnose or monitor conditions affecting amino acid metabolism, though it is not a standalone diagnostic tool.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical significance: Elevated or low threonine levels in hair fluid can indicate underlying metabolic dysfunctions, though interpretation requires correlation with clinical symptoms and other diagnostic tests. This test is often part of a comprehensive metabolic workup.

Short name

Hair Threonine Profile

Frequently asked questions

What does a 'free threonine' test in hair fluid measure exactly?
It measures the concentration of free (unbound) threonine, an amino acid, in a 24-hour fluid sample collected from hair follicles. This reflects long-term amino acid metabolism in your body.
Can this test detect genetic metabolic disorders?
While it may help identify amino acid imbalances, this test alone is not definitive for genetic metabolic disorders. Your healthcare provider will use results alongside clinical findings and other tests for diagnosis.
How often is this test performed?
This test is usually ordered as a one-time or specialized diagnostic procedure, depending on clinical needs. It is not a routine screening test for most patients.
  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