Lifelabs Ontario Testosterone Reference Ranges
I cannot provide the specific reference ranges used by Lifelabs in Ontario, as this proprietary laboratory information is not contained in the available evidence.
Standard Laboratory Reference Ranges for Adult Male Testosterone
The normal total testosterone range for adult men is 300-800 ng/dL in most North American laboratories 1. However, this represents a general standard rather than Lifelabs-specific values.
Age-Specific Considerations for Normal Ranges
The traditional 300 ng/dL cutoff may not be appropriate for younger men, as testosterone levels vary significantly by age:
- Men in their 20s: The middle tertile (normal range) is approximately 409-575 ng/dL, with low testosterone defined as <409-413 ng/dL 2
- Men in their 30s: The middle tertile is approximately 350-498 ng/dL, with low testosterone defined as <350-359 ng/dL 2
- Men in their 40s: Expected range is 251-914 ng/dL (2.5th-97.5th percentile), with abnormally low defined as <251 ng/dL 3
- Men in their 50s: Expected range is 216-876 ng/dL, with abnormally low defined as <216 ng/dL 3
- Men in their 60s: Expected range is 196-859 ng/dL, with abnormally low defined as <196 ng/dL 3
- Men in their 70s: Expected range is 156-818 ng/dL, with abnormally low defined as <156 ng/dL 3
Critical Measurement Requirements
Two separate fasting morning testosterone measurements (drawn between 8-10 AM) are required for accurate diagnosis of testosterone deficiency 4. This is essential because:
- Testosterone levels fluctuate significantly throughout the day, with peak levels in the morning 1, 4
- Single measurements are unreliable for diagnosis 4
- Only 13 clinical trials in comprehensive reviews actually required proper 2 fasting morning measurements 4
Common Clinical Pitfall
Up to 25% of men receiving testosterone therapy do not actually meet diagnostic criteria for testosterone deficiency 4, and nearly half of men on testosterone therapy never have their levels checked after starting treatment 4.
To Obtain Lifelabs-Specific Ranges
Contact Lifelabs directly or review the reference ranges printed on your specific laboratory report, as these may differ from the general North American standards cited above and can vary by testing methodology (immunoassay vs. LC-MS/MS) 5.