TRT and fertility - what you need to know if you want children

One of the most important conversations we have with men starting TRT is about children. The standard testosterone regimen suppresses the pituitary, suppresses LH, suppresses FSH, and consequently suppresses sperm production. Many men on stable TRT have azoospermia (no sperm) or severe oligozoospermia (very few sperm) within three to six months of starting.

If you have finished your family, this rarely matters. If you have not, it matters a lot. Here is the full picture.

Why TRT suppresses fertility

Exogenous testosterone suppresses GnRH release from the hypothalamus, which reduces LH secretion from the pituitary, which reduces intratesticular testosterone concentrations, which reduces sperm production. Intratesticular testosterone needs to be 50 to 100 times blood concentration for normal spermatogenesis. TRT flattens this gradient.

The suppression is dose-dependent and reversible in most men, but reversal can take 3 to 12 months after stopping, and a minority of men do not fully recover sperm counts.

If you are planning children soon

Do not start TRT. Full stop. The downside of delaying TRT for 12 to 24 months while you complete your family is vastly smaller than the downside of dealing with TRT-induced infertility afterwards.

If your hypogonadal symptoms are severe and life is not tolerable without treatment, the alternatives worth considering are clomiphene citrate (a selective oestrogen receptor modulator that raises endogenous LH, FSH, and therefore testosterone while preserving spermatogenesis) or HCG monotherapy (directly stimulates testicular Leydig cells). Both of these raise testosterone without shutting down sperm production. They are not perfect substitutes for TRT but they are viable bridges.

If you are not sure about children

This is the commonest scenario. You are in your thirties or early forties, symptoms are real, you may or may not want more children, your partner may or may not be in agreement. The conservative approach is sperm cryopreservation before starting TRT.

Sperm banking costs £250 to £500 for three samples plus annual storage (£50 to £150 per year). It is boring but straightforward. Samples are viable after thawing for many years. This buys you the option of assisted conception later without having to reverse the TRT.

We routinely recommend this to any man under 45 starting TRT who is not definite he has completed his family. The cost is modest and the regret-avoidance is substantial.

If you are on TRT and now want children

Two scenarios: you have banked sperm (straightforward, use IVF or IUI with the stored sample) or you have not (more complicated).

If you have not banked sperm, the standard approach is to stop TRT and add stimulation. HCG 1500 to 3000 IU subcutaneous twice weekly, sometimes combined with clomiphene, sometimes with FSH injections, restarts the testicular machinery in most men. Sperm production usually returns in 3 to 12 months. Around 10 to 20 percent of men do not recover counts adequate for natural conception and may need IVF with testicular sperm extraction.

The recovery is faster in men who were younger when they started TRT, who were on TRT for shorter durations, and who had normal baseline fertility parameters before TRT. Older men, long-duration TRT users, and men with baseline oligozoospermia before TRT recover more slowly and less completely.

HCG alongside TRT - the fertility-preserving regimen

Some men want to start TRT but preserve fertility without banking. This is possible with a combined regimen of testosterone plus low-dose HCG 500 IU twice weekly. The HCG maintains intratesticular testosterone concentrations and usually preserves sperm production, though not always.

This regimen costs more (an extra £40 to £80 per month for HCG plus consumables) and involves an additional injection. It also needs closer monitoring because the testicular response is variable. We typically check a semen analysis at 3, 6, and 12 months to confirm spermatogenesis is preserved.

If it works, it is excellent. If the semen analysis shows suppression despite HCG, the options are escalating HCG dose, adding FSH, or accepting that preservation has not worked and falling back to sperm banking.

What a fertility-preserving consultation looks like

If you are under 50, in a relationship, and have not finalised your family, we spend meaningful time on this at first assessment. Specific questions: are you trying now or in the near future, what is your partner's age and fertility status, have you banked sperm before, have you had a semen analysis, and what is your preference between conservative (no TRT until family complete), banked-sperm-then-TRT, or combined TRT/HCG regimen.

We will sometimes recommend a semen analysis before starting TRT to establish baseline fertility. Around 10 to 15 percent of men have subclinical infertility before they start TRT that they did not know about. Knowing this changes the calculation about preservation.

Relationship and ethical dimensions

Fertility decisions are not yours alone if you are in a relationship. Starting TRT without discussion with your partner is something we actively discourage. If your partner is not aware of the fertility implications, or wants further children and you have not talked about it, we pause the TRT conversation until that one has happened.

This is not us being preachy. It is us trying to prevent the very common bad outcome where a man starts TRT, finds out in his late forties that a new partner wants children, and then faces a complicated and expensive reversal. That scenario is avoidable with a proper conversation at day one.

What happens after vasectomy

If you have had a vasectomy, TRT and fertility are disentangled (the vasectomy has already handled the fertility question). You can go onto standard TRT without the considerations above. This is often the cleanest presentation we see.

The honest bottom line

TRT is not a lifestyle accessory. It is a medical treatment with known fertility implications. If children are a consideration, this needs to be discussed explicitly before starting. We offer clomiphene, HCG, sperm banking, and combined regimens. We also recommend waiting until your family is complete when that is realistic, because the simplest option is often the best.

Ready to start?

If this article has made you think an assessment might help, the next step is a short consultation with one of our men's health doctors.

Begin your consultation at this link. Online or in person at Westfield London.