I have gotten good results from stacking 6-oxo, Vitrex, Dhea, and Action Lab's liquid Avena sativa. I feel some definite libido increase and great pumps, and increased muscularity. 6-oxo is an anti-aromatase that lowers estrogens and raises testosterone. Vitrex has liquified concentrated forms of tribulus and eurycoma..which raises test by stimulating leutinizing hormone. Dhea in large doses raises testosterone , but does so without supressing your own output. The Avena sativa causes a release of "Free" testosterone. 6-oxo is off the market but amazon.com sells a 6-oxo clone. This stack should raise your natural test levels pretty good and will not shut you down if you go off. This has enabled me, at 46 years old, to still produce youthful test levels (verified by hormone blood tests).
6oxo will boost test and lower estrogen, but theres no evidence that this will cause any changes in body composition.
tribulus anecdotally does increase libido, but there is no evidence that it increases LH or test.
DHEA has been shown to restore natural test levels in some men with sub normal test levels. but theres no evidence that it would ever increase test levels beyond normal, or provide any benefit to a healthy man with normal test levels.
avena sativa, while im not familiar with it, it seems it probably lowers the amount of sex hormone binding gobulin. (SHBG). wich would result in more unboudn test, "free test". this is possible, but there is no evidence to believe this would be beneficial either... as its quite possible that bound test can interact with androgen receptors just like unbound test can....and in fact if this is the case(which it likely is) then bound test would be superior to unbound test, as bound test is protected from metabolism and stays in circulation for much longer than unbound test(which is quickly and easily metabolised)