I decided to conduct an experiment to see what the discrepancy would be between two different labs on my estradiol test. In the past I had seen some wild numbers between the two, but the tests were done at different intervals over time. This time I decided to have my estradiol level checked at two different labs within one hour.
My first stop was at Quest Diagnostics and my blood was drawn at 6:30 AM. I then went to LabCorp and had my blood drawn at 7:30 AM (done through Life Extension). I got my results back today. Both labs used the same scale: 0-54 pg/mL. The results:
LabCorp: estradiol 30 pg/mL
Quest: estradiol 79 pg/mL
I know this can't be right - not even close. I've been using anastrazole @ 4 drops per day for three months. I am on TRT and using Testim 5 grams daily since October 2006 after being diagnosed with hypogonadism (Total T: 135 ng/dL; Free T: 30.0 pg/mL). My T levels now are:
Total T: 1438 pg/mL
Free T : 491.8 pg/mL
Based on the way I feel I'm going with LabCorp because I don't feel like my E2 is 79. However, it does make me curious. The only side effects that are bothering me is side pain on my right side (hip/glute), minor back pain and stiffness, but I figure that is due from years of heavy training and not elevaed E2. In the past, the right side hip/glute pain has alerted me to using too high of a dosage of anastrazole. Obviously, even at 30 pg/mL, that can't be the case.
How can these two labs be this far off? Which one is more reliable? Quest or LabCorp?
Thanks in advance for any thoughts that you might have for me.