The body naturally fluctuates on a daily basis. You will never be able to mimic that injecting with esters like cypionate or enanthate (even if you inject on a daily basis). Maybe with testosterone suspension you can argue you can. Creams will work better in that regard
It depends on the ester. I know that EOD enanthate makes my testosterone very constant, whereas daily propionate can make my testosterone vary by up to +/-50% about the mean.
This is wrong. SHBG does not affect the rate of absorption of injected testosterone, which is what leads to measured half-lives.
"rate of clearance"
Still not stated correctly, because on average you cannot clear faster than you absorb, regardless of SHBG. And if he's not referring to the apparent half-lives of testosterone esters then it should be spelled out clearly, because most would assume that it is about serum testosterone over time after an injection. These half-lives do not change with SHBG.
This relates to a different half-life, the half-life of pure testosterone in the bloodstream, which is on the order of minutes to a couple hours. Even so, you cannot metabolize and excrete testosterone you don't have. Lower SHBG might mean faster clearance if more testosterone entered the system to maintain total testosterone. But this is not what happens with injections. Instead, the constant slow absorption of testosterone acts to maintain free testosterone, and it is total testosterone that adjusts to match, being lower when SHBG is lower.
Would you mind explaining why it seems to be necessary for guys with low shbg to inject so frequently, if the rate of absorption are basically the same and free T is maintained? I'm trying to wrap my head around this concept as "low shbg = more frequent injections because the testosterone is expelled so quickly" is what I've heard forever. If it's as you're saying, it doesn't seem that frequent injections would offer any real benefit at all?
One idea is that low SHBG enhances sensitivity to hormonal fluctuations, with unnatural hormonal variations being worse with respect to the ratio of free testosterone to free estradiol. "James" expands a little on the idea here. "I believe the fluctuations we see in low SHBG men that require 3x-7x weekly dosing are due to rapid and highly exaggerated changes in free estradiol due to the above phenomenon as peaks and troughs radically alter free hormone binding and metabolism in the absence of proportionate quantities of SHBG."
This is the mythology I'm trying to debunk. Differing SHBG levels do not change the apparent half-lives of injected testosterone esters. As I've explained before, after you inject a testosterone ester you have this oily depot in muscle or under the skin. The depot slowly dissolves, releasing the testosterone ester, which eventually gets into the bloodstream, where enzymes cleave the ester and release the pure testosterone. Only then is the testosterone free to interact with other molecules, such as SHBG. The apparent half-life of a testosterone ester is determined by how fast its depot dissolves. This is not influenced by SHBG.
Were these measurements taken under controlled conditions with frequent samples in the period of interest? This is what would be needed to see what's really going on. Nonetheless, if you have compelling data then feel free to share the details. If we're relying on anecdotes, then in just about every case where a guy has given me two clean, post-peak measurements after a testosterone cypionate injection, the computed half-life has been close to five days.
Don't you use frequent injections though? The some reasoning behind that for you is the free e2 control or something else?
I'd done pretty well on EOD enanthate or cypionate for some years—never tried anything else, but was curious if daily propionate would be an improvement. I'm currently experimenting with using both esters in different ratios, so I can adjust the amount of daily variation. Given the small data set and lack of isolation of the variables, I can't say anything definitive. However, the transition to propionate gave me the best two weeks I've had on TRT with respect to libido and sexual function. Otherwise, any long-term improvements are subtle at best.
