Definition: "An ergogenic aid is any substance or phenomenon that enhances performance "

about us





Study: hCG makes testes bigger, but no increase in testosterone

If men with low testosterone levels want to increase the size of their testicles, then hCG will do the job. But if these same men want to boost their testosterone levels, they'll achieve better effects with a testosterone gel, according to endocrinologists at the Gulhane School of Medicine in Ankara, Turkey.

We stumbled across this Turkish study on, Nelson Vergel's [ 10-07-2014] Vergel is an expert on testosterone therapy, and author of the standard work on the subject Testosterone – A Man's Guide. []

In their study [Clinical Endocrinology (2013) 79, 243–251.] the endocrinologists compared the effects of three different treatments: an injection of 5000 IU hCG twice a week, an injection of 250 mg Sustanon every three weeks, and daily application of gel containing 50 mg testosterone.

The hCG that the Turkish researchers used was Organon's good old Pregnyl [hCG]. Organon was of course also the manufacturer of Sustanon [TE], and the gel that the researchers used was Testogel manufactured by Schering [TG].

The researchers gave these products for six months to three groups each consisting of two dozen hypogonadal men. All the men had testosterone levels that were below 300 ng/dl and none had entered puberty spontaneously.

Administration of hCG resulted in a decrease in the amount of triglycerides [Delta TG; above right in the figure below] in the men’s blood. In addition, hCG caused the least reduction in the concentration of 'good cholesterol' HDL [above left].

The figure at bottom right shows that hCG resulted in an increase in testicle size compared with the other treatments. And that's what you'd expect: hCG mimics the effect of the hormone LH, which induces growth of the testes and increased testosterone production. What you perhaps might not have expected is that hCG has no effect on the testosterone concentration in the blood [bottom left].

Study: hCG makes testes bigger, but no increase in testosterone

The researchers don't know why hCG didn't boost testosterone production in their study, as in other studies hCG does do this. [Hum Reprod. 1997 May;12(5):980-6.] [Hum Reprod. 2004 Jul;19(7):1558-61.] A difference between this study and others is that the subjects in this one were aged between 18 and 29. The subjects in the other studies were older.

Study: hCG makes testes bigger, but no increase in testosterone
"This study suggests that human chorionic gonadotropin [hCG] treatment may be a favourable option regarding testicular volume and the lipid parameters", the researchers conclude. "However, when testicular volume is considered less important, particularly in older subjects with hypogonadotropic hypogonadism, testosterone gel application seems to be ideal because of its easy use, neutral effects on triglyceride, haemoglobin and haematocrit, and beneficial effects on total cholesterol level."

"Testosterone enanthate may be the last alternative treatment for hypogonadotropic hypogonadism. Prospective studies with larger sample size and longer observation periods are required to identify the best treatment approach in patients with hypogonadotropic hypogonadism."

Clin Endocrinol. 2013;79(2):243-251.

Case study: hCG restores testosterone production after steroids use 26.02.2010