External androgens shut off LH and FSH, and without FSH the testes stop making sperm. Counts fall toward zero within weeks to months of use and recover over months after stopping, usually but not always. Current users show severely reduced AMH and inhibin B; some former users are still hypogonadal years later. If children are on the horizon: bank sperm before, keep exposure short, and know that hCG and SERMs are the clinical tools for restarting.
- Sperm production needs FSH and high intratesticular testosterone; external androgens suppress both by silencing the pituitary.
- Current users in Rasmussen's study had severely decreased AMH and inhibin B, markers of impaired spermatogenesis; former users had lower testosterone and more hypogonadal symptoms years after stopping.
- Recovery of sperm production after stopping typically takes 3–12 months and is slower after longer or continuous exposure.
- Nasal testosterone's short pulses largely spare LH and FSH, which is why it is the one route that preserves fertility.
- hCG mimics LH and keeps the testes working during exposure; SERMs restart the pituitary afterwards. Both are prescription tools used in clinical hypogonadism.
The mechanism
Sperm are made in the testes under two signals: FSH from the pituitary, and testosterone produced locally inside the testis at concentrations far above blood levels. External androgens tell the brain there is plenty of hormone, LH and FSH fall to near zero, the testis stops producing its own testosterone, intratesticular levels collapse, and sperm production stops. Blood testosterone being high does nothing for sperm; it is the local production that matters, and that is switched off.
What the markers show
| Marker | What it reflects | On androgens |
|---|---|---|
| LH, FSH | pituitary signal | near zero |
| Inhibin B | Sertoli cell function (sperm support) | severely reduced in current users |
| AMH | testicular function | severely reduced in current users |
| Semen analysis | the outcome | counts fall toward zero within months |
| Testicular volume | activity | shrinks |
Rasmussen’s cohort documented the inhibin B and AMH collapse in current users, and found former users still low in testosterone and symptomatic years after stopping.
Recovery
Sperm take roughly 74 days to mature, so the first two months after the axis restarts show nothing. Typical recovery of counts: 3–12 months after the compound clears and LH and FSH return. Slower after long or continuous exposure, after several compounds, and with age. A minority need treatment to restart; a smaller minority do not recover.
Protecting fertility
Before. Semen analysis and hormones for a baseline. Bank sperm if children are possible in the next years. It is the single most effective step and it is cheap.
During. Shorter exposure and real breaks: recovery scales with time on. Nasal testosterone is the one route whose short pulses leave LH and FSH largely intact. In clinical practice hCG is used alongside testosterone to keep the testes producing; it is a prescription medicine with its own monitoring, not a supplement.
After. Confirm the restart with LH, FSH and testosterone, then a semen analysis three months later. If the axis has not restarted in the expected time, the clinical tools exist: SERMs to restart the pituitary, hCG to drive the testes, both from the hypogonadism literature reviewed by Rahnema.
Planning a pregnancy
Time off before trying: enough for the axis to restart plus three months for sperm to mature, confirmed by a semen analysis rather than assumed. For women who use androgens, the equivalent is cycle recovery; the women’s article covers it.
The trade-off in one line
Every depot androgen suppresses sperm the entire time it is in you. Banking before and keeping exposure defined are what keep the option open; years of continuous use are what close it.
Frequently asked questions
Do steroids make you infertile?
While in use, yes for almost everyone: sperm counts fall toward zero. After stopping, production usually returns over months. Permanent infertility is uncommon but the risk rises with years of continuous exposure.
How long until sperm comes back?
Sperm take about 74 days to mature, so nothing changes in the first two months. Most men recover counts over 3–12 months after the compound clears and the axis restarts; some take longer, a few do not recover without treatment.
Can I stay fertile while on?
Nasal testosterone preserves LH and FSH and is the only route that largely does. Otherwise, hCG during exposure keeps the testes active in clinical practice, but it is a prescription medicine with its own management.
Should I bank sperm?
If children are a possibility in the next decade, yes, before starting. It is cheap relative to fertility treatment, takes an afternoon, and removes the question.
Which test shows where I stand?
A semen analysis, plus LH, FSH and testosterone. Inhibin B and AMH reflect testicular function directly. Test before starting for a baseline and after stopping to confirm recovery.
Sources
- Rasmussen JJ et al. Former abusers of anabolic androgenic steroids exhibit decreased testosterone levels and hypogonadal symptoms years after cessation. PLoS One, 2016.
- Rahnema CD et al. Anabolic steroid-induced hypogonadism: diagnosis and treatment. Fertility and Sterility, 2014.
- Bhasin S et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. JCEM, 2018.
- Comparison of hematocrit change in testosterone-deficient men treated with intranasal testosterone gel vs intramuscular testosterone cypionate: a randomized clinical trial. 2023.