The reason for limiting a course to 40 injections is that by then some patients may begin to show signs of HCG immunity. Though this phenomenon is well known, we cannot as yet define the underlying mechanism. Maybe after a certain length of time the body learns to break down and eliminate HCG very rapidly, or possibly prolonged treatment leads to some sort of counter-regulation which annuls the diencephalic effect.
After 40 daily injections it takes about six weeks before this so called immunity is lost and HCG again becomes fully effective. Usually after about 40 injections patients may feel the onset of immunity as hunger which was previously absent. In those comparatively rare cases in which signs of immunity develop before the full course of 40 injections has been completed-say at the 35th injection- treatment must be stopped at once, because if it is continued the patients begin to look weary and drawn, feel weak and hungry and any further loss of weight achieved is then always at the expense of normal fat. This is not only undesirable, but normal fat is also instantly regained as soon as the patient is returned to a free diet.
Patients who need only 23 injections may be injected daily, including Sundays, as they never develop immunity. In those that take 40 injections the onset of immunity can be delayed if they are given only six injections a week, leaving out Sundays or any other day they choose, provided that it is always the same day. On the days on which they do not receive the injections they usually feel a slight sensation of hunger. At first we thought that this might be purely psychological, but we found that when normal saline is injected without the patient's knowledge the same phenomenon occurs.