N-acetylcysteine in serum/plasma (24-hour fluid collection)
This test measures the amount of N-acetylcysteine, a compound your body naturally produces to help protect your organs from damage caused by harmful chemicals or toxins.
["N-acetylcysteine helps support liver and kidney function by reducing oxidative stress in fluid samples collected over 24 hours."]
Key facts at a glance
- LOINC
- 33212-2
- Short code
- N-Ac-L-Asp Fld-mCnc
- Synonyms
- N-Ac-L-Asp Fld-mCnc
- 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 Is This Test Done?
Your healthcare provider may order this test if you have or are at risk for conditions that affect your liver, kidneys, or exposure to toxins (e.g., certain medications, industrial chemicals, or smoking-related toxins). It can also be part of monitoring for metabolic or genetic disorders that involve oxidative stress.
What Does the Test Involve?
You’ll collect a 24-hour urine sample (or sometimes serum/plasma if fluid is directly measured) to capture total N-acetylcysteine levels over time. The sample is tested for the presence of this compound using a specialized laboratory method.
What to Expect Before the Test
No special preparation is typically required, but follow your provider’s instructions carefully. If collecting urine, empty your bladder before starting and collect all urine for the full 24-hour period, including at night. If serum/plasma is used, no fasting is needed, but avoid certain medications or supplements that might interfere.
What to Expect During the Test
If a urine sample is collected, you’ll likely be instructed to use a timed container. If serum/plasma is drawn, a blood sample will be taken from a vein, usually in your arm, by a healthcare professional.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated levels may indicate excessive oxidative stress, potentially linked to liver disease, kidney dysfunction, or exposure to toxins. Lower-than-expected levels could suggest metabolic or genetic conditions affecting antioxidant defenses. Results help guide treatment for conditions like cystic fibrosis, certain cancers, or chronic exposure to toxins.
Short name
N-Acetylcysteine Level
Frequently asked questions
What does an abnormal N-acetylcysteine level mean?
How often will I need this test?
Can diet or supplements affect this test?
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