Do steroids stop you from having children?

Short answer

While using, most men's sperm counts drop sharply. Most recover after stopping, but sperm took about 1 year, and 34% still had low sperm counts at the final check.

Do steroids stop you from having children?
'Steroids → 0 sperm → infertile for good' — does this formula hold?
There is a claim that steroids shrink the testicles and make you unable to have children. We checked the research in three stages: while using, after stopping, and years later.
What happens to sperm while using?
77 of 100 dropped below 40 million sperm
In a study following 100 men starting a steroid cycle, 77% had their total sperm count fall below 40 million during use. In a contraception study giving 271 healthy men weekly testosterone shots, 65% reached 0 sperm within 6 months, and there was 1 pregnancy over 1,486 months.
Does it come back after stopping?
In contraception studies, everyone recovered within 2 years
An analysis of 30 testosterone contraception studies with 1,549 men found sperm took a median of 3.4 months after stopping to return to a fertility benchmark (20 million per mL). 67% recovered within 6 months, 90% within 1 year and 100% within 2 years.
Real users took longer
At the last check, 34% still had low sperm counts
In the same 100-man study, testosterone mostly returned within 3 months of stopping, but sperm took about 1 year. At the final check, 34% (25 men) still had a sperm count below 40 million, and 11% (9 men) had below-normal testosterone.
The longer the use, the slower the recovery
Sperm took 14.1 months on average to recover
A study compared 41 current users, 31 men who had stopped a median of 300 days earlier, and 21 non-users. Apart from smaller testicles, past users did not differ from non-users. Sperm output took 14.1 months on average to recover, and longer use meant slower recovery.
Some still had effects years later
5 years after stopping, 27% had low testosterone
Of 33 men who had stopped 2.5 years earlier on average, 27% had testosterone below the normal range for young men. None of the 30 non-users did. Past users also reported low sex drive (40%) and erection problems (27%) more often than current users or non-users.
What clinics saw
43% of 97 men with very low testosterone had used steroids
Among 6,033 men treated for low testosterone, the most common cause in the 97 with very low levels was past steroid use (42 men, 43%). In a survey of 382 men, past steroid use went along with having fewer children.
Summary: sperm dropped sharply in most users
Most recovered after stopping, but it took a year and 34% stayed low
During use, 77% had their sperm count fall below 40 million. Most recovered after stopping, but sperm took about 1 year, and 34% were still low at the final check. Longer use meant slower recovery, and 2.5 years later 27% still had low testosterone.