Androgen receptors can be "clogged"... heres how:
Androgen receptors are activated when
agonists such as testosterone binds to them or other steroids which mimic testosterone. However, when
antagonists binds to the receptor, it prevents the agonist testosterone from binding thus no activation.
A SERM for example (
Selective Estrogen Receptor Modulators) will act as an
antagonist to estrogen by binding to estrogen receptors in some places in the body such as the chest, but act as the
agonist to some places in the body and actually activate the estrogen receptor. They are selective.
So within the body you have agonists and antagonists. Agonists such as testosterone activate androgen receptor ... and antagonists such as
anti-androgens bind to the receptor and do nothing but block the real testosterone from binding.
The androgen receptors are found within the cytoplasm of the cell. Think of the cytoplasm as the blood of the cell, it's just the fluid where everything is floating in.
Heres the critical part... androgen receptor quantities within the cell cytoplasm can increase or decrease and the cell can control this.
The cells of the body practice down-regulation where the cell decreases a quantity of a cellular component (such as androgen receptors) or up-regulation where it increases the numbers of a cellular component (such as androgen receptors).
So, not only do agonists and antagonists play a role, the
numbers of androgen receptors which goes up and down can also affect gains.
Not enough receptors... no gains... too much receptors... hello gains. (Assuming anti-androgens are in small amounts).
Now what determines the numbers of androgen receptors?
ANDROGENS!!!!
In this study they found that androgens caused down-regulation of androgen receptors in the cells of a rats penis (cell decreasing androgen receptors in response to androgens).
http://ajpendo.physiology.org/cgi/content/abstract/258/1/E46
So we see androgen down-regulation thanks to androgens can be very local and not as systemic. But nonetheless, androgens CAN and DO down-regulate androgen receptors.
My theory
Put in copious amounts of steroids, and the body might catch on, and somehow produce more antagonists such as anti-androgens to block steroids from binding in an attempt to reach homeostasis thus slowing down gains.
Or/And,
Put in copious amounts of steroids, and those same steroids cause down-regulation of androgen receptors (cells in the body decrease number of androgen receptors) thus slowing down gains.
Both situations are very plausible.
What you need to prevent this from happening is something that prevents anti-androgen formation, and something that up-regulates androgen receptors taken together during a cycle... holy sh*t you could gain forever like that (unless the body is smarter than we think which I think it is, and finds another damn way to reach homeostasis).
But go find me anti-androgen inhibitors and androgen receptor up-regulators that can be ingested and you can probably prevent this lol.
So yes, I would take enough time off... how much? Time on + PCT = time off, should be enough. Because you could quite possibly enter your next cycle too early with either too much anti-androgens in your system from previous cycle, or not enough androgen receptors due to down-regulation from previous cycle in which case you get nothing from the new cycle (My answer is based on my theory).