A common misconception about the Selective Androgen Receptor Modulator (SARM) S4 , also known as Andarine, is its half-life.
The Human Equivalent Half-Life Of S4 In Preclinical Studies
The preclinical data states that the half-life of S4 is only 4 hours in humans [R].
When I experimented with S4 myself, my dosing protocol was designed based upon this statistic, and you will often see others suggest that twice per day dosing is mandatory to maintain even relatively stable blood serum concentrations of this SARM due to its “short half-life”.
I have found this 4 hour statistic to be completely incorrect in practical application.
Data showing the pharmacokinetics of S4 in humans has never been published, so this statistic suggests that it was either pulled out of a scientists ass, or there was some sort of unpublished trial on humans at some point.
The fact that S4 is now an abandoned SARM suggests that it may in fact have been tested on humans at some point.
Perhaps the night vision side effect is what led to its abandonment in the first place, but that is unknown at this time and is all just speculation on my part.
The discovery of the night vision side effect was stumbled across by accident (no pun intended) via anecdotal findings years ago, and to date the supposed half-life of four hours is still circulated around the community, despite it taking several days to restore uninhibited sight at certain dosages.
The Real Half-Life Of S4 In Humans
Anybody who has dosed S4 high enough to a point where they broke the barrier and entered hulk vision, sepia-filter mode, can attest to the fact that it takes longer than 24 hours to restore vision after discontinuation of the SARM.
Personally, I noticed that there seems to be an accumulative effect with S4.
When I tried S4, I titrated up to 50 mg per day slowly, always splitting my dosage into a morning and nightly administration.
By the time I reached 30 mg, I was already noticing the vision side effect.
I pushed my way up to 50 mg and the vision side effect just became substantially more prominent.
I left the dose at 50 mg to evaluate whether my body would acclimate and the side effect would start to go away on its own, but the opposite happened, it continued to get worse despite stopping my upward titration.
I was sitting on the porch of a cabin underneath what was supposedly an amazing sky full of stars.
I couldn't see anything.
I couldn't even see the drink I had in my chair's cupholder 2 feet from my face.
Accumulative Serum Concentrations Of S4
I pulled the dosage all the way down to 10 mg a day afterwards.
Things did not improve, even after several days.
I soon realized that the half-life of S4 was much longer than 4 hours.
I stopped using it entirely and then kept a close eye on how long it took to resolve itself.
For the first few days, there was no improvement.
After about a week, I finally started to see things go back to normal.
After that experience, I came to the conclusion that the half-life of S4 is probably closer to that of a SARM like LGD-4033, if not longer.
My educated guess is that the human equivalent half-life is closer to 36 or 48 hours, rather than 4.
Granted, while this is based entirely on my own anecdotal findings, I can say with near certainty that the half-life of S4 is not 4 hours like most have been led to believe.