Do Steroids Affect Sperm Count and Fertility?

Anabolic steroids and testosterone taken for muscle are among the most reliable ways to lower a man’s sperm count, often all the way to zero. Extra testosterone from outside the body makes the brain switch off the signals that drive a man’s own sperm production.¹ In effect, the drug that builds muscle works like a male contraceptive, and researchers have tested it on purpose as one.² The effect is usually reversible, though recovery is slow and isn’t guaranteed for everyone.³

How Much Steroids Lower Sperm Count

Among men seen for problems after steroid abuse, about 8 in 10 had abnormal semen.⁴ About two-thirds had a low sperm count, below 15 million per millilitre, averaging around 6 million.⁵ About 6 in 10 had sperm that swam poorly.⁶ In men seen at a fertility clinic after steroid use, half had no sperm at all.⁷ These figures come from men who sought help, not from all users. The true share may be lower.

Two words show up on semen reports. Oligospermia means a low sperm count, below about 15 million per millilitre. Azoospermia means no sperm were found in the sample.

Quality suffers as well as numbers. Steroid-related infertility usually comes with sperm that move poorly and are oddly shaped.⁸ In rats given high doses of nandrolone, sperm DNA was damaged and pregnancy rates fell.⁹

A semen report lists count, movement and shape separately, so a man can pass on one measure and fail another. Poor swimming alone can make conception slow.

The only way to know where you stand is a semen analysis. You give a sample, usually after a few days without ejaculating, and a lab counts and examines the sperm under a microscope. Counts vary naturally from sample to sample, so doctors often ask for a second test before drawing conclusions. Blood hormone tests usually go alongside it, because they show whether the shutdown comes from the brain’s signals being switched off.

Why Steroids Shut Down Sperm Production

The brain sends two hormones, LH and FSH, that tell the testicles to make testosterone and sperm.¹⁰ When extra testosterone arrives from outside, the brain reads the level as high and cuts these signals.¹¹ The testicles’ own testosterone then drops, and sperm lose the signals they need to mature.¹² On prescribed testosterone, the level inside the testicles fell by 94%.¹³

Blood levels can be high while the testicles run low. Sperm making depends on very high testosterone inside the testicles, not on what the blood carries.¹⁴ FSH alone cannot keep sperm production going.¹⁵ A high or normal blood reading says nothing about whether sperm are being made, because only the testicles’ own production can supply the concentration they need inside.

The testicles also shrink, by about a fifth after four months of weekly testosterone injections.¹⁶ The more they shrank, the more the sperm count fell.¹⁷

Shutdown can also bring a lower sex drive and erection problems, and hormone imbalance can cause breast tissue to grow. Many men notice nothing at all until they try for a baby.

How Long Recovery Takes After Stopping

After stopping prescribed testosterone, sperm returned to a normal 20 million per millilitre in about 3 to 6 months on average.¹⁸ About 2 in 3 men recovered by 6 months, 9 in 10 by a year, and nearly all by 2 years.¹⁹ For illegal steroid use the evidence is thinner, with recovery usually in 4 to 12 months.²⁰ Some men take 2 to 3 years.²¹ Sperm take roughly three months to develop, so even after hormones restart, counts lag behind and an early semen test can look worse than the eventual result.

The clock also starts later than the last dose. Testosterone from injections can linger for weeks, depending on the form, so the brain is still being suppressed after you stop. Only once the drug has cleared does the brain start sending its signals again, and that restart is when real recovery begins.

Several things slow recovery. Higher doses, longer use, and stacking several steroids all lengthen it.²² Older age and poor fertility before starting slow it down too.²³ Asian ethnicity has been linked to slower recovery.²⁴ And full recovery doesn’t happen in every man.²⁵

To track progress, repeat semen tests every few months show whether counts are climbing. Blood tests for LH, FSH and testosterone show whether the brain signals have restarted. Tell the doctor honestly what you used, for how long and at what dose, because that history shapes how long they expect recovery to take.

If counts haven’t improved after several months, see a fertility doctor rather than waiting year after year. Couples who are older or short on time should ask about treatment early.

Prescribed Testosterone Versus Bodybuilding Steroids

Form matters. Long-acting injections cut FSH by about 86%.²⁶ Daily gels or patches cut it by about 60%.²⁷ A short-acting nasal gel cut it by about 38%.²⁸ Longer-acting testosterone suppressed the testicles’ own hormone making more.²⁹

A man on prescribed testosterone can be caught out even at a medical dose, because the same brain feedback that shuts down sperm production happens at medical doses. A man with low testosterone who wants children may need a different treatment, one that stimulates his own production rather than replacing it.

If you’re a TRT patient who wants children, ask whether a shorter-acting form fits your plans and whether adding hCG is an option to protect sperm. Mention fertility plans before starting.

Bodybuilding doses are usually far above medical ones, so suppression is often deeper and longer-lasting.³⁰ A prescription is one known drug at a measured dose, so a doctor can anticipate its effect and monitor it. A bodybuilding stack mixes several drugs, some of which suppress the brain’s signals through different routes, so the effects pile up. Many users also take drugs continuously or with short breaks, leaving little time for the testicles to restart. Underground products may not contain what or how much they claim.

Treatments That Can Help Restore Fertility

hCG is an injected hormone that acts like LH and keeps the testicles producing testosterone.³¹ With low-dose hCG alongside testosterone, testicular testosterone fell only 7% instead of 94%.³² Sperm production was still preserved at one year.³³

It is usually considered for men on testosterone who want to protect their fertility, or for men whose testicles have shut down and need to be woken up. It is given by injection several times a week, which is a commitment compared with a pill. Because it acts on the testicles directly, it can work even while the brain’s own signals are still switched off. It is a prescription medicine, with the dose set from blood tests and semen results.

Clomiphene, a pill, blocks estrogen’s signal to the brain so it releases more LH and FSH.³⁴ The body then makes its own testosterone again, and sperm production can recover.³⁵ It is often used off-label as “post-cycle therapy.”

Because clomiphene works at the brain level, it needs a brain that can still respond, and it suits men who have stopped testosterone and want their own production back. Men typically take it as a daily or every-other-day pill for months, with blood tests to check that the signals are rising. It makes no sense while still on testosterone, since the outside supply keeps the system suppressed. Side effects can include mood changes and vision disturbances, which is a reason to take it under medical supervision. Running post-cycle therapy yourself is risky: doses bought online are unverified, and without blood tests you can’t tell whether recovery has started.

A visit to a fertility doctor, ideally a urologist or male fertility specialist, starts with a semen test and blood hormone tests. They may stop testosterone and add hCG or clomiphene. If counts stay at zero, sperm can sometimes be retrieved for IVF.

SARMs and Muscle Supplements

In rats, some SARMs lowered testosterone and markedly suppressed sperm production.³⁶ One shrank the testicles.³⁷ In another rat study, though, the effect fully reversed after stopping.³⁸

SARMs are drugs designed to act like testosterone on muscle, and they still act on the same hormone system, so suppression of the body’s own signals is a realistic concern. Most of the fertility data come from animals. They aren’t approved as medicines for muscle building, so there is no body of human safety data to point to, and products sold online often aren’t what the label says. Being “not a steroid” doesn’t mean sperm are spared.

Supplements carry their own risk. In supplements bought in 13 countries, about 15% contained undeclared steroids.³⁹ A muscle supplement could therefore lower your sperm count without your knowledge.⁴⁰

If you’ve taken SARMs or a doubtful supplement, stopping is the first step, since the suppression is driven by continued use. A semen analysis and hormone blood tests show whether production has been affected. Give the doctor the exact product name, because some supplements contain drugs not on the label. Recovery is plausible, as in the rat study, but nobody can promise it for a given man.

Steroids and Women’s Fertility

Steroids can disrupt the brain hormone that drives the ovaries.⁴¹ Periods can become rare or stop, and ovulation can stop.⁴² Infertility can result.⁴³

The ovaries depend on the same kind of brain signals as the testicles, released in a monthly rhythm that triggers an egg to mature and be released. Extra androgens can interfere with that rhythm, so the egg isn’t released and the period becomes irregular or stops. Without ovulation a woman cannot conceive, which is why this can show up as a fertility problem.

Missed or irregular periods are the clearest warning. A deepening voice or changes in body hair suggest strong androgen effects. A woman planning a pregnancy should tell her doctor about any steroid use.

If she has used steroids and wants a pregnancy, stopping is the first step, since the disruption depends on the drugs being in the body. A doctor can check hormone levels and whether she is ovulating, using blood tests and tracking of periods. Research on recovery in women is limited, so medical follow-up is worth having. Women whose partners use steroids aren’t directly affected, but the partner’s own fertility may need checking.