Quick Facts
- Sample: 24-hour urine collection
- Fasting: No fasting required
- Turn-around Time: 2-4 business days. May take longer based on weather, holiday or lab delays.
Benefits
- Accurate thyroid health assessment - measures iodine status over 24 hours for reliable results
- Convenient at-home collection - no doctor visit required, collect sample at home
- Early detection of imbalances - identifies iodine deficiency or excess before symptoms appear
- Metabolism optimization support - helps maintain proper thyroid hormone production for energy
- Treatment monitoring capability - tracks iodine levels during thyroid disease management
- Creatinine-adjusted accuracy - corrects for urine concentration variations for precise measurements
Who Is This Test For?
- Individuals with thyroid disorders (hypothyroidism, hyperthyroidism, autoimmune thyroiditis)
- People taking iodine supplements or iodine-containing medications
- Those experiencing unexplained fatigue, weight changes, or metabolic issues
- Health-conscious consumers monitoring their nutritional status proactively
- Individuals at risk of iodine deficiency or excess exposure
- People preparing for or managing thyroid disease treatment
How It Works – Just 3 Steps
- Order and receive collection kit - no prescription needed, kit delivered to your home
- Collect 24-hour urine sample - follow simple instructions, refrigerate sample throughout collection
- Ship to lab and get results - send sample using provided materials, receive confidential results online
FAQ
What does this test measure? Iodine concentration in your 24-hour urine collection, adjusted for creatinine to ensure accuracy regardless of urine concentration.
How is this different from a spot urine test? 24-hour collection provides more accurate assessment of your overall iodine status compared to single urine samples that can vary throughout the day.
Do I need to stop supplements before testing? Avoid iodine-containing supplements or contrast agents if possible, but consult your healthcare provider about specific medications.
Can this test diagnose thyroid disease? No, it assesses iodine status that affects thyroid function but should be combined with thyroid hormone tests for complete evaluation.
What if my results are abnormal? Consult a healthcare provider to discuss results and potential dietary changes, supplementation, or further thyroid function testing.
Is the collection process difficult? No, detailed instructions are provided. Simply discard first morning urine, then collect all urine for 24 hours while keeping sample refrigerated.
More Details
What is the purpose of this test?
This test measures the amount of iodine your body excretes over 24 hours, providing insight into your iodine nutritional status. Iodine is essential for thyroid hormone production, which regulates metabolism, energy, and cardiovascular health. The test uses inductively coupled plasma mass spectrometry (ICP/MS) for highly accurate measurements (Mayo Clinic 2025). By adjusting results for creatinine, the test accounts for urine concentration differences, ensuring reliable assessment of your iodine status.
Who would benefit from this test?
Anyone concerned about thyroid health or iodine status can benefit from this test. It's particularly valuable for people with existing thyroid conditions, those taking iodine supplements, or individuals experiencing symptoms like unexplained fatigue or weight changes. Health-conscious consumers use it for preventive monitoring, while those on iodine-containing medications need it for safety monitoring (WHO 2021). The test is also recommended for people living in areas with known iodine deficiency or excess.
When should I order this test?
Order this test when you suspect iodine imbalance, before starting thyroid treatment, or to monitor existing thyroid conditions. It's recommended if you're taking iodine supplements, have symptoms of thyroid dysfunction, or want to assess your nutritional iodine status proactively (NIH 2023). Consider testing if you've had recent exposure to iodine-containing contrast agents or medications, or if you're following dietary restrictions that might affect iodine intake.
How do I interpret the results?
Iodine Level: Below 75 mcg/24h
- What It Means: Iodine deficiency
- Typical Action: Increase iodine intake through diet or supplements
Iodine Level: 75–851 mcg/24h
- What It Means: Within normal range
- Typical Action: Maintain current iodine intake
Iodine Level: Above 851 mcg/24h
- What It Means: Possible excess iodine
- Typical Action: Reduce iodine sources and monitor thyroid function
Creatinine ratio helps ensure accuracy by correcting for urine concentration - your results will include both measurements for complete assessment.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
Pre-test preparation
No fasting or special dietary restrictions are required. However, avoid iodine-containing contrast agents or supplements for several days before testing if possible. Continue regular medications unless specifically advised otherwise by your healthcare provider. Ensure you have the proper collection container from the lab before starting your 24-hour collection period (Mayo Clinic 2025).
How often should I get tested?
Circumstance: Initial Screening
- Suggested Interval: Once, then as needed
Circumstance: Thyroid Disease Monitoring
- Suggested Interval: Every 3–6 months
Circumstance: Supplement Adjustment
- Suggested Interval: 1–3 months after changes
Circumstance: High-Risk Individuals
- Suggested Interval: Annually
Why early detection matters
Approximately 2 billion people worldwide are at risk of iodine deficiency, a leading cause of preventable thyroid disorders (WHO 2021). Early detection of iodine imbalance helps prevent hypothyroidism, hyperthyroidism, and related complications. With over 90% sensitivity for detecting iodine status changes, 24-hour urine testing enables timely intervention before symptoms develop. This proactive approach can reduce healthcare costs and improve quality of life by maintaining optimal thyroid function and metabolism.
Related tests you may consider
Thyroid-stimulating Hormone (TSH) Blood Test - Measures TSH levels for detecting or diagnosing thyroid issues.
Free T3 and Free T4 Blood Test Panel - Evaluates thyroid function if a thyroid disorder is suspected.
Thyroid Antithyroglobulin Antibody (TAA) Blood Test - Measures TAA levels to screen for autoimmune disorders like thyroiditis.
Comprehensive Metabolic Panel (CMP-14) with eGFR Blood Test- Evaluates nutrient levels, liver, and kidney function.
Selenium Blood Test - Checks the amount of selenium in your blood, essential for immune support, thyroid function, and antioxidant defense, helping doctors identify deficiencies or excesses that could affect your health.
