Disruption and recovery of testicular function during and after androgen abuse: the HAARLEM study

Disruption and recovery of testicular function during and after androgen abuse : the HAARLEM study / D.L. Smit, M.M. Buijs, O. de Hon, M. den Heijer, W. de Ronde. - (Human Reproduction (2021) deaa366; p. 1-11)

  • PMID: 33550376
  • DOI: 10.1093/humrep/deaa366


Study question: What is the speed and extent by which endogenous testosterone production and spermatogenesis recover after androgen abuse?

Summary answer: Testosterone concentrations normalized within 3 months after discontinuation of androgen abuse in most subjects but recovery of spermatogenesis took longer-approximately 1 year.

What is known already: An estimated 4-6% of amateur strength athletes use androgens. Abuse of supraphysiological doses of androgens completely suppresses endogenous testosterone production and spermatogenesis.

Study design, size, duration: Prospective and observational cohort study in which 100 male amateur athletes participated for 1 year.

Participants/materials, setting, methods: Subjects (≥18 years) were included if they had not used androgens for at least 3 months and intended to start an androgen cycle within 2 weeks. Clinic visits took place before (T0), at the end (T1), and 3 months after the end of the cycle (T2), and 1 year after start of the cycle (T3), and included a blood test for gonadotrophins and sex hormones, and semen analysis.

Main results and the role of chance: During androgen abuse, 77% of subjects had a total sperm count (TSC) below 40 million. Three months after the end of the cycle (T2), total (-1.9 nmol/l, CI -12.2 to 8.33, P = 0.71) and free (-38.6 pmol/l, CI -476 to 399, P = 0.86) testosterone concentrations were not different compared to baseline, whereas mean TSC was 61.7 million (CI 33.7 to 90.0; P < 0.01) lower than baseline. At the end of follow-up (T3), there was no statistically significant difference for total (-0.82 nmol/l, CI -11.5 to 9.86, P = 0.88) and free (-25.8 pmol/l, CI -480 to 428, P = 0.91) testosterone compared to baseline, but there was for TSC (-29.7 million, CI -59.1 to -0.39, P = 0.05). In nine (11%) subjects, however, testosterone concentrations were below normal at the end of follow-up (T3), and 25 (34%) subjects still had a TSC below 40 million.

Limitations, reasons for caution: The follow-up period (after the cycle) was relatively short, especially considering the long recovery time of spermatogenesis after discontinuation of androgens.

Wider implications of the findings: Endogenous testosterone production and spermatogenesis recover following androgen abuse in the vast majority of users. Nevertheless, not all users achieve a normalized testicular function. This may especially be the case for athletes with a high past exposure to androgens.

Study funding/competing interest(s): There is no conflict of interest. The study was funded by the Spaarne Gasthuis academy.

Trial registration number: N/A.

Keywords: anabolic steroids; androgens; bodybuilding; post-cycle therapy; semen analysis; testosterone.


Research / Study
7 February 2021
Buijs, Madelon M.
Heijer, Martin den
Hon, Olivier de
Ronde, Willem (Pim) de
Smit, Diederik L.
Other organisations
Amsterdam Universitair Medische Centra (Amsterdam UMC) - Amsterdam University Medical Center
Dopingautoriteit - Doping Authority Netherlands
Spaarne Gasthuis - Spaarne Hospital
Doping classes
S1. Anabolic Agents
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Health effects
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Scientific article
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Pdf file
Date generated
10 February 2021
Date of last modification
11 February 2021
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