Using these two international consortia, we aimed to extend our prior study in the EHNBPCCG to assess the associations of circulating concentrations of calculated free testosterone, as well as total testosterone and SHBG which are used to calculate free testosterone, with overall, aggressive and early‐onset prostate cancer risk using blood‐based and genetic methods; using these complementary approaches can provide more robust evidence for causal inference. Here, SHBG is linked to Familial prostate cancer.