A few months into testosterone therapy, many men notice something nobody warned them about: their testes are smaller. For some it is only cosmetic. For men who still want children, it is a sign that sperm production has slowed or stopped, because the testosterone coming from outside has told the body it no longer needs to make its own.
HCG is the add-on that keeps the testes working while you are on TRT. This guide explains why the shutdown happens, how HCG prevents it, who should consider it, what a typical protocol looks like and how we monitor it at Alpha Medical in Limassol.
Why TRT switches the testes off
The testes make testosterone and sperm on instruction from the brain, through a hormone called LH. When testosterone arrives by injection or gel, the brain senses there is plenty and cuts LH almost to zero. Without that signal, the testes stop producing.
The drop inside the testes is far bigger than blood tests suggest. Testosterone concentration inside the testis is normally around a hundred times higher than in the blood, and sperm production depends on it. In a study of healthy men given weekly testosterone injections for three weeks, testosterone inside the testes fell by 94%. Blood levels looked excellent the whole time.
What HCG does
HCG (human chorionic gonadotropin) acts on the same receptors in the testes as LH. In effect, it stands in for the signal that TRT has switched off. The testes keep making testosterone internally, keep their size and keep supporting sperm production.
In that same study, adding small doses of HCG every other day kept testosterone inside the testes close to normal: within 7% of the starting level at 250 IU, and slightly above it at 500 IU. The effect rose steadily with the dose.
Fertility on TRT with HCG
In a group of 26 men with an average age of 36 who took TRT together with low-dose HCG, semen quality stayed the same for more than a year of follow-up. None of them lost sperm production entirely, and 9 of the 26 achieved a pregnancy with their partner during that time. Their testosterone rose from low to well within the healthy range.
That is why the American Urological Association's guideline advises that men who want to keep their fertility should not rely on testosterone alone. For them, HCG with TRT, or a different approach such as enclomiphene, is the safer plan.
Who should consider HCG
HCG is not needed by everyone on TRT, but it is worth discussing if any of these apply:
- You want children now or in the next few years
- You are bothered by testicular shrinkage or aching
- You may want to come off TRT later and restart your own production more easily
- You feel that TRT alone leaves something missing in libido or well-being, which some men report improves with HCG
- You are young, with many years of treatment ahead
What a typical protocol looks like
HCG is given as a small injection under the skin, usually two or three times a week, alongside your usual testosterone. The studies above used doses in the range of 250 to 500 IU every other day, and protocols typically sit in that range. Your physician sets the dose from your bloodwork and goals, and it is often lower than people expect.
It is a simple injection with a very fine needle. We teach you to do it at the first visit, and it becomes part of the weekly routine within a couple of weeks.
Oestradiol and what we monitor
Because HCG keeps the testes producing testosterone, some of that testosterone is converted to oestradiol. In most men this stays in a healthy range, but some notice water retention, nipple sensitivity or mood changes if it climbs too high.
We check total and free testosterone, oestradiol and haematocrit at 6 weeks, 3 months and then every 6 months, and adjust the HCG dose, the testosterone dose or both. For men focused on fertility, we add a semen analysis at the start and at intervals so there is a clear record.
HCG, enclomiphene or both?
HCG works directly on the testes, so it keeps them active even when the brain's signal is fully switched off by TRT. Enclomiphene works on the brain, raising LH and FSH, so it helps only when you are not on full-dose testosterone. Men who want children soon sometimes stay off TRT and use enclomiphene instead; men who want the reliability of TRT add HCG. When coming off TRT, the two are sometimes used in sequence to restart natural production.
We explain the options side by side at the consultation, with your blood results in front of us.
Ready to take the next step? Book a consultation at our contact page — or request an introductory TRT guide below.
