Short answer: It can. Testosterone from outside the body signals the brain to cut the hormones that tell the testes to work, so the testes make less testosterone and sperm. The AndroGel 1.62% label lists testicular atrophy (shrinking) and low sperm counts among problems reported during use. The labels do not say how often or how much. Changes in size or tenderness are worth raising with your prescriber.
The testes make testosterone and sperm when the pituitary gland sends two hormones, LH and FSH. When testosterone comes from a gel or a shot, the brain senses enough testosterone and turns those signals down. The AndroGel 1.62% label (section 5.8) says that with large doses of outside androgens, sperm production may be suppressed through feedback inhibition of pituitary FSH, which may lower sperm count.
The American Urological Association (AUA) guideline on testosterone deficiency puts it this way: testosterone therapy suppresses the testes' own testosterone production, and that internal testosterone is needed for normal sperm production. The testes do less work, which is why they can get smaller.
| Label | Section | What it says |
|---|---|---|
| AndroGel 1.62% (gel) | 5.8 | Large doses may suppress sperm production through feedback on FSH, which may lower sperm count |
| AndroGel 1.62% (gel) | 6.2 and 8.3 | Testis disorder (including atrophy), testicular atrophy and low sperm count reported during use; reduced fertility seen in some men on TRT |
| Depo-Testosterone (injection) | Precautions | Low sperm count may occur after prolonged use or excessive dosage |
The AndroGel findings come from reports after approval, which show that something happened but not how often. Neither label gives a rate for shrinking or a measure of how much. The labels also note that testicular atrophy and infertility have been reported in men who misuse anabolic steroids.
For men who may want children, the AUA guideline says a reproductive check, including a testicular exam for size and an FSH level, should happen before starting therapy. It also says the long-term effect of testosterone on sperm should be discussed, and that testosterone should be stopped ahead of trying to conceive.
On recovery, the guideline cites contraception studies in which two-thirds of men had sperm back in the ejaculate within six months of stopping, while 10% did not until the second year. It notes recovery is less well studied in men who already had fertility problems.
For men who want to keep fertility, the guideline says clinicians may use hCG, a SERM such as clomiphene, an aromatase inhibitor, or a mix (a conditional recommendation, based on lower-grade evidence). These aim to keep the testes' own testosterone production going. The hCG on TRT article covers the evidence, and fertility on TRT covers the options.
The labels do not say shrinking needs any action by itself, but tenderness, pain or a lump are worth mentioning. Useful notes: when you started, the product and dose, any change in size or feel and when you noticed it, and whether fertility matters to you now or later.
Dose Track keeps your doses, lab results and notes on one timeline, so the start date and later changes are easy to show at a visit.
Read more on Dose Track: Fertility on TRT · hCG on TRT and fertility · AndroGel side effects · Depo-Testosterone side effects · Enclomiphene vs clomiphene