I thought that a low dose of S4 doesnt affext the HPTA
From:
http://www.ncbi.nlm.nih.gov/pmc/arti...8/?tool=pubmed
"The activities of S-4 on LH and FSH were similar to those produced by TP. S-1 and S-4 partially suppressed LH production at dose rates of 0.5 mg/day or higher."
An absolute dose of 0.5 mg/day is equivalent to 1.9 mg/kg/day in the rats studied. When corrected for body surface area and converted to dosing for humans, you get 0.31 mg/kg (1.9 * 0.162). As a theoretical extrapolation, for a 100 kg (220 lb) man, a dose of only 31 mg/day is where you'd start to see "partially suppressed LH production."