Leucine Amino Acid Load (24-hour urine collection)
This test measures the amount of the amino acid leucine excreted in your urine over a 24-hour period. It helps assess how well your body is breaking down proteins and processing amino acids.
["This test helps evaluate protein metabolism and kidney function."]
Key facts at a glance
- LOINC
- 25163-7
- Short code
- Leucine Cry #/area UrnS HPF
- Synonyms
- Leucine Cry #/area UrnS HPF
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- microscopy-light-hpf
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order a leucine amino acid load test if they suspect conditions like kidney disease, metabolic disorders, or improper protein digestion. It can also be used to monitor how well certain medications or treatments affect your body’s protein metabolism.
What to Expect Before the Test
You’ll need to collect all urine for a full 24-hour period. Start by emptying your bladder completely at the beginning of the test (time zero). Seal the collection container and continue collecting all urine until you repeat the initial emptying at the end of the 24 hours. Keep the container refrigerated if possible to preserve the sample.
During the Test
No special preparation is needed beyond the urine collection. You’ll likely be given instructions on how to properly collect and store your urine samples. If you have any dietary restrictions or medications, let your provider know to avoid interference.
After the Test
After completing the 24-hour urine collection, your sample will be sent to a lab for analysis. Results may take several days to process. Follow-up with your healthcare provider to discuss any findings.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
What does a leucine amino acid load test measure?
Results typically take 3 to 7 business days to be processed and reported by the lab. Your healthcare provider will contact you once the results are ready.
No, there is no pain or discomfort associated with this test. The only requirement is collecting urine over 24 hours, which involves standard urine collection techniques.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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