Does oral testosterone add to your existing natural levels or will it suppress natural levels?

busydad · Monday at 5:59 PM

For example, if your current natural levels are at 400, and you take oral testosterone will the oral testosterone add to the level of your natural testosterone or could it possibly suppress your natural production and maybe make your levels actually lower depending on how well you absorb the oral medication?

madman · Monday at 10:11 PM

busydad said:
For example, if your current natural levels are at 400, and you take oral testosterone will the oral testosterone add to the level of your natural testosterone or could it possibly suppress your natural production and maybe make your levels actually lower depending on how well you absorb the oral medication?

All formulations of exogenous T will inhibit the HPG axis to some degree!

Oral testosterone undecanoate (200-237 mg twice daily depending on the formulation)

Tlando: Incomplete suppression in men with hypogonadism

Kyzatrex: Incomplete suppression (~65% reduction) in men with hypogonadism

Jatenzo: Incomplete suppression (~70% reduction) in men with hypogonadism

* Exogenous testosterone is contraindicated in men trying to conceive, but new short-acting formulations, including oral testosterone undecanoate and nasal testosterone gel, might incompletely suppress the hypothalamic–pituitary–gonadal axis and partially preserve spermatogenesis.

Thread 'Dynamic landscape of therapeutic options for T deficiency in reproductive-aged males and their impact on suppression of the HPG-axis'

May 10, 2025

Most up to date paper!

As usual Nelson house is where its at!

Exogenous T formulations impact on suppression of the HPG axis.

Here is a quick breakdown from most--->least suppressive!

As we have stated numerous times on the forum ultra short-acting Natesto is where its at!

Table 1 | Formulations of testosterone replacement therapy and their effects on male reproductive parameters

Published effects on FSH and LH

LONG-ACTING FORMULATIONS

Nebido/Aveed: Complete or near complete suppression

T-pellets: Strong suppression (90% reduction)

INTERMEDIATE-ACTING...

* By 2022, however, the FDA approved three preparations of testosterone undecanoate in which the androgen is suspended in a self-emulsifying drug delivery system that results in peak levels 4–6 h after intake93,94. Testosterone undecanoates typically dosed twice daily, as testosterone levels return to baseline levels ~8–12 h after achieving peak concentration95

* Considering this short half-life, inhibition of the HPG axis is likely weaker than that achieved with longer-acting testosterone formulations.

* These modest reductions in LH and FSH reflect an incomplete suppression of the HPG axis, which suggests that spermatogenesis might be maintained during oral testosterone undecanoate therapy. Most available literature does not provide information on semen parameters following oral testosteroneundecanoate, but in a very small prospective pilot study, endocrine and semen parameters were assessed in 5 hypogonadal men after 3 months of treatment. In this study, one patient experienced azoospermia, whereas the remaining four patients did not show statistically significant differences in sperm count (P = 0.53), motility (P = 0.10)or volume (P = 0.66) after 3 months98. These results are interesting, but this small study has an inadequate sample size to draw definitive conclusions. Further studies are needed to evaluate whether fertility can be maintained on self-emulsifying oral testosterone undecanoate. Oral formulations cannot yet be recommended as a fertility-sparing approach owing to the lack of clear evidence showing preservation of spermatogenesis. Furthermore, current AUA guidelines on testosterone deficiency recommend that TRT of any kind should not be prescribed to men trying to conceive54.