Insulin, Intact, LC/MS/MS

Catalog information reviewed: August 24, 2026 by the Sunridge Medical clinical team.

What this laboratory test evaluates

DetailsInsulin, Intact, LC/MS/MS – This test measures insulin levels to help understand blood sugar control and fat metabolism. It's mainly used to find out why a patient might have low blood sugar (hypoglycemia). High insulin levels can indicate hypoglycemia or conditions related to high blood sugar, like metabolic syndrome. Reasons for high insulin include various health issues, such as insulinoma (a tumor in the pancreas), insulin resistance, and others. This test, especially when combined with C-peptide measurement, can also assess insulin resistance or help distinguish between different causes of abnormal blood sugar levels.

What patients is this test right for?This test is suitable for individuals experiencing symptoms of low or high blood sugar, or for those who might be at risk of insulin resistance or related conditions.

Low Blood Sugar Symptoms:• Shakiness
• Sweating
• Hunger
• Dizziness
• Confusion
• Weakness

High Blood Sugar Symptoms:• Increased thirst
• Frequent urination
• Fatigue
• Blurred vision

What type of sample is required for this test?0.5 mL serum.

Test Resources https://www.questdiagnostics.com/healthcare-professionals/clinical-education-center/faq/faq170

Additional test information

This test measures insulin levels to help understand blood sugar control and fat metabolism. It's mainly used to find out why someone might have low blood sugar (hypoglycemia). High insulin levels can indicate hypoglycemia or conditions related to high blood sugar, like metabolic syndrome.

Collection and processing

• Sample type: Serum
• Fasting: Yes
• Estimated laboratory processing: Results should be available in 2 – 5 business days after the sample is collected

How Sunridge uses laboratory information

Sunridge considers the medical question, symptoms, history, medications, prior results, and whether the finding could change care before recommending testing. A laboratory result is not interpreted in isolation and does not establish a diagnosis by itself.

Before requesting this test

Availability, collection requirements, eligibility, and processing estimates can change. Sunridge reviews each request and, when appropriate, creates the order through Fullscript. Follow the current instructions supplied with the approved order.