I assume you mean the same one I have posted before... the treatment of oligospermic was a 6-9 month study - which proved nolva was better... and the shorter term proving nolva was better was on normal men...
I am looking for more studies on this... nolva does restart the hpta very well though... here is what I have found so far
Treatment of idiopathic and postvaricocelectomy oligozoospermia with oral tamoxifen citrate
Kadioglu, Köksal, Tunç, Nane & Tellaloglu
The FSH, LH and testosterone levels increased in all groups receiving tamoxifen citrate; while FSH levels increased by 50%, LH and testosterone levels almost doubled in normogonadotrophic patients. The hormone level increases were less prominent in hypergonadotrophic men. Semen analysis in all groups showed no change in any variable other than sperm concentration and count. Normogonadotrophic men had a significant increase in sperm count and concentration, while the slight increase detected in hypergonadotrophic men was statistically insignificant.
Tamoxifen citrate is preferred to clomiphene citrate as its oestrogenic activity is practically insignificant Clomiphene citrate is a combination of two isomers and exerts both anti-oestrogenic and oestrogenic effects simultaneously. The oestrogenic effect increases plasma oestrogen levels in men with oligozoospermia and increased FSH levels. Thus testosterone and sex-hormone binding protein synthesis may decline, decreasing spermatogenesis. Because tamoxifen lacks this intrinsic oestrogenic effect, it may be more appropriate to use in male infertility. Although tamoxifen is also a trans isomer, animal and human studies confirm its oestrogenic activity to be minimal or negligible