Highlights•Testosterone levels decrease in men who get married.
•Testosterone levels increase in men who get divorced.
•The capacity for testosterone production did not differ according to marital status.
•The biological mechanisms behind these findings remain unresolved.
Based on a large population of 1113 men aged 30–60 at baseline (mean: 44.1 years, standard deviation: 10.5), we investigated whether intra-individual changes in testosterone (T) and related reproductive hormones during a ten year period were dependent of marital status at baseline and follow-up. The studied men were part of a health survey in Denmark, conducted between 1982 and 1984 with a follow-up examination approximately ten years later. Data on reproductive hormones, measured in serum, and lifestyle and marital status was obtained at both time points. As expected, an age-related decline in testosterone was observed. However, independent of age and lifestyle, we observed that men who went from unmarried to married (n = 81) during the study period experienced an accelerated age-related decline in testosterone (−6.6 nmol/L) whereas men who went from married to unmarried (n = 67) experienced an attenuated age-related decline (−2.3 nmol/L). Men who were either married or unmarried at both time points (n = 167, n = 798, respectively) had a testosterone decline in between (−3.7 nmol/L and −4.6 nmol/L, respectively). Changes in T/LH ratio did not differ according to marital status indicating that the lowered T level is not compensated by increasing LH levels. This could suggest a modification of the gonadostat due to an adaptation to changing life circumstances.