will post what big cat wrote on the topic of stacking tren and testesterone in a thread on bbing.com , its very informative :
"Well when commencing the test protocol I usually employ increments of 250 mg. So 500 test, up to 750, 1000 and possibly in larger individuals 1250. At 1000 or slightly above you will however notice that the increase in gains is considerably less. More testosterone means more estradiol leading to increased SHBG activity and less androgen receptor occupation increase. Then we add the tren. Likewise, we would use a similar dose increase, with perhaps 250-350 mg of tren per week, amounting to 35-50 mg ed. Then potentially in very elite athletes up to 75 mg, but I'm theorizing that at this point you will have 95-100% occupation of androgen receptors and further increases of any steroid for that purpose would be futile.
Nandrolone is useful in that regard that it is 19Nor and thus resistant to binding and metabolization, allowing it to fill the receptors that testosterone has difficulty filling beyond a certain dose due to increased binding to proteins. But then I would still opt for trenbolone. Out of the body faster, more resistant than nandrolone, equally active in muscle and a heck of a lot more active in all other tissues. Its basically a DHT that works in muscle (3 times as strong an AR affinity as test but no deactivation). I always advise against nandrolone.
The nature of gains dictates that the best course of action is test, until the linear increase in Ar occupation starts to attenuate, usually around 1 to 1.2 grams of test per week. At which point adding more test yields less results as doses increase due to higher binding by proteins. It is then wise, if we still wish to continue the increase in effect, to fill the remaining AR with an androgen that is as potent or more so, but more resistant to binding proteins. trenbolone being the wiser choice, being 3 times more androgenic than testosterone in all tissues and highly resistant due to its triple double bond and 19Nor structure. This will allow the continuation of the linear increase, increasing gains at a lower cost than with increased test. An added benefit being that it is less progestational than nandrolone and does not convert to estrogen, since we are adding it to 1gram of test ...
If we then still wish to continue, the only logical addition is the only steroid known to work in an entirely different fashion than testosterone, namely winstrol. Structure indicates poor binding, poor muscle building qualities and the list goes on, but it does appear to express very weird characteristics that very rarely overlap with testosterone, making it really the only drug that is synergistic with test. It is the only hormone that exhibits strong binding to the microsomal AR, while it has next to no binding at other AR. That would indicate a strong expression of a function not activated by test. It is highly active in the liver, in fact to such an extent that the liver expresses a binding protein that is specific to stanozolol, STBP. Where testosterone can bind only one form of the cortisol receptor, stana binds to both, increasing the anti-catabolic effect. It increases calcium reabsorption from the kidneys, which then normalizes calcium depression in the serum as a result of testosterone induced calcium influx in the muscle and liver. It increases collagen synthesis, which could strengthen tendons, which is always an upside in steroid users and lastly it is known to cause growth through a form of programmed cell death and increases in energy independent of the AR.
With these three, I see really no room to add anything else. It would be overkill. Mind you, you could keep upping the doses of all of this with great succes to the point where you are using 2+ g of AAS per week. Which is an extremely large dose."
save it 
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