Quick Facts
- Sample: Blood
- Fasting: Fasting for at least 8 hours is required
- Turnaround: 4-5 business days (may take longer due to weather, holidays, or lab delays)
What's Included
This test measures how your body processes lactose by tracking blood glucose across five separate blood draws. The first draw is taken while fasting to establish your baseline glucose level. You then drink a lactose-containing beverage, and blood is drawn again at 30, 60, 90, and 120 minutes afterward.
Each draw is analyzed for glucose (five total glucose measurements). If your glucose does not rise as expected after the lactose beverage, it suggests your body is not breaking lactose down efficiently, which is consistent with lactose intolerance. This is a single, standalone functional test, not a broader digestive or food allergy panel.
Benefits
- Tracks how your body metabolizes lactose over time
- Uses five measurements for a detailed glucose response curve
- Helps clarify symptoms linked to dairy consumption
- Supports informed conversations with your healthcare provider
- Non-invasive way to evaluate lactose digestion
Who Is This Test For?
- People with bloating, cramps, or diarrhea after dairy
- Individuals with a family history of lactose intolerance
- Parents seeking clarity on a child's dairy-related symptoms
- Those planning meals around suspected lactose sensitivity
- People with ongoing digestive symptoms after eating dairy
How It Works
- Order Your Test Online
- Visit a Local Lab
- Get Results Online
FAQ
1. What does this test measure?
This test measures your blood glucose response after drinking a lactose beverage, using five separate draws (fasting, then 30, 60, 90, and 120 minutes later). The pattern of glucose change over that window indicates how well your body digests lactose.
2. Who should consider this test, and when?
People experiencing bloating, gas, cramping, or diarrhea after consuming milk or dairy products are often candidates for this test, as are those with a family history of lactose intolerance. It may also be considered for babies or young children with suspected dairy-related digestive trouble, or for anyone wanting clarity before adjusting their diet.
3. Do I need to fast or prepare for this test?
Fasting for at least 8 hours is required before this test. No additional preparation instructions are specified beyond this fasting window.
4. How long does it take to get results?
Results are typically available in 4-5 business days, though this may take longer depending on weather, holidays, or lab-specific delays.
5. What happens during the test itself?
Blood is drawn five times over the course of a few hours: once while fasting, then again at 30, 60, 90, and 120 minutes after you drink a lactose beverage. This allows your provider to see how your glucose changes over time rather than at a single point.
6. How should I interpret my results, and what if they're abnormal?
Interpretation depends on how your glucose levels changed across all five draws, along with your symptoms and health history. A glucose rise that is lower than expected suggests your body may not be digesting lactose efficiently, but a qualified healthcare provider should review your full results in context.
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.
If your results fall outside the expected range, discuss them with your healthcare provider, who can help determine appropriate next steps based on your full clinical picture. This test does not diagnose a condition on its own or provide dietary or treatment instructions.
7. Is this test available everywhere?
This test is not available at all patient service centers (PSCs). Confirm availability with your chosen location before ordering.
Pre-test preparation
Fasting for at least 8 hours is required before this test. No other diet, medication, supplement, timing, or activity instructions are specified for this test.
