There are no studies from which we can conclude which protocol/dosing is ideal...
As LS already said the standard 2 week protocol at the end of the cycle works fine for most, but throughout the cycle may be superior, especially if you plan to stay on very long...
Low doses are definitely the way to go...
http://physiol.annualreviews.org/cgi/content/full/60/1/461?ijkey=6GsNUBGIkSk22
Pulsatile endogenous LH secretion or exogenous pulsatile or
single low-dose treatment with LH or hCG maintains LHR levels and steroidogenic enzymes in the adult Leydig cell. However, experimental or endogenous elevations of hCG secretion (e.g. as in patients with choriocarcinoma), major increases in LH levels, or
administration of a single pharmacological dose of LH or hCG can cause down-regulation of the LHR and desensitization to the hormonal signal (13, 22).
In this study the effect of single high dose was compared to the effect of divided small dose..
J Clin Endocrinol Metab 1984 Feb;58(2):327-31 Related Articles, Links
Differential effect of single high dose and divided small dose administration of human chorionic gonadotropin on Leydig cell steroidogenic desensitization.
Smals AG, Pieters GF, Boers GH, Raemakers JM, Hermus AR, Benraad TJ, Kloppenborg PW.
This study compared the effect of a single high dose of hCG (1500 IU) with that of the same dose administered in multiple small doses (300 IU, once daily for 5 days) on Leydig cell steroidogenesis. Administration of a single high dose of hCG to seven healthy men raised the mean plasma testosterone (T) level to peak levels 2.1 +/- 0.2 (SEM) X the baseline value at 48 h. Thereafter plasma T decreased to below normal (0.7 +/- 0.1 X baseline) 7 days after the injection. The mean 17-hydroxyprogesterone (17-OHP) level peaked at 24 h (2.5 +/- 0.2 X baseline) and then also fell to a nadir value of 0.6 +/- 0.2 X baseline on day 7. Reflecting the early accumulation of 17-OHP over T, the 17 OHP/T ratio reached its maximum (1.6 +/- 0.1 X baseline) at 24 h at the same time when plasma estradiol [(E2) 4.4 +/- 0.6 X baseline] and the ratio E2/T (2.7 +/- 0.3 X baseline) achieved their maximal values.
Administration of 1500 IU hCG in five divided doses of 300 IU daily increased the mean plasma T levels to peak value of 2.1 +/- 0.2 X baseline at 5 days and the levels remained elevated thereafter. The response of T as reflected by the area under the curve was almost twice as great as in the single dose study (2844 +/- 360 vs. 1647 +/- 214). In contrast to the single high dose experiment, mean plasma 17-OHP levels in the divided dose protocol did not peak at 24 h but only gradually increased. As the increase of T exceeded the 17-OHP increase at almost all time intervals, no accumulation of 17-OHP over T occurred as in the single dose experiment. Instead the 17-OHP/T ratio fell to a nadir value of 0.6 +/- 0.1 X baseline on day 7. The initial E2 peak was absent in the divided dose protocol and the E2/T ratio only marginally increased. Considering both experiments together a close relation was found between the hCG-induced increases in E2 and 17-OHP (r = +0.88, P less than 0.001), as well as the ratio 17 OHP/T (r = +0.64, P less than 0.02).(ABSTRACT TRUNCATED AT 400 WORDS)
EOD or E3D may be a better option than ED:
J Clin Endocrinol Metab 1979 Jul;49(1):12-4
Leydig cell responsiveness to single and repeated human chorionic gonadotropin administration.
Smals AG, Pieters GF, Drayer JI, Benraad TJ, Kloppenborg PW.
A single im injection of 1500 IU hCG significantly increased plasma testosterone levels for at least 96--120 h in normal men (n = 7), patients with isolated gonadotropin deficiency (n = 6), and boys with delayed puberty (n = 7); the maximum values [1315 +/- 309, 370 +/- 177, and 963 +/- 249 ng/100 ml (mean +/- SD), respectively] were achieved after 72 h in each group. Repeated daily injections of 1500 IU hCG for 3 days increased plasma testosterone levels in the same subjects at 72 h after the start to levels (1342 +/- 412, 407 +/- 199, and 1052 +/- 449 ng/100 ml, respectively) similar to those found in the single dose experiment. The levels achieved at 24 and 48 h also did not differ significantly in the two experiments. The data indicate the lack of additional leydig cell stimulation by repeated hCG injections given within 48 h after a single dose.
