As part of a workup for potential acromegaly (due to elevated IGF-1), my endocrinologist (not the doc who follows me for TRT) asked me to take 4 weeks off my TRT to see if it normalized my IGF-1. I’d been on TRT nonstop since April 2012, so 6.25 years. On August 21st I had my last shot (for the time being). I will go back on after another round of bloodwork this coming week.
On Tuesday September 4th, I had interim bloodwork done to see how things were showing up for T and IGF-1. My levels were lower than I’d expect based on the half-life of cypionate and I’m wondering if this tells me anything about how my body handles testosterone.
As an example:
Steady-State TRT Levels, Prior to Coming Off
Testosterone 805.65 ng/dL Ref Range 123.06 - 813.86 ng/dL Free Testosterone 191 pg/mL Ref Range 47 - 244 pg/mL
No Shots for 14 Days:
Testosterone 127 ng/dL Ref Range 264 - 916 ng/dL Free Testosterone 4.3 pg/mL Ref Range 8.7 - 25.1 pg/mL
Here’s what I’m wondering:
- Based on an average half-life of 8 days, I would expect that my remaining testosterone levels after stopping abruptly would be higher than they were.
- Is this reasonable, or does an 85% drop in testosterone levels after 2 weeks of no shots seem lower than expected?
- If this is unusual, could this tell me anything about SHBG levels, aromatization, or other pathways that regulate T levels in my body?
- I know half-lives are an average but I’m wondering if this level is at all helpful to learn something about my unique physiology.