Differential Effects of 3.5 GHz and 24 GHz 5G Radiofrequency Exposure on Male Sexual Behaviour and Reproductive Endocrine Function in Rats

The rapid expansion of 5G technology has increased exposure to high-frequency radiofrequency electromagnetic fields (RF-EMF), raising concerns about male reproductive health. This study investigated the effects of 5G frequencies at 3.5 GHz and 24 GHz on male libido, reproductive hormones, the testosterone-to-oestrogen (T/E) ratio, and androgen receptor expression in rats. Eighteen male Sprague–Dawley rats were randomly assigned to Control, 3.5 GHz, and 24 GHz (n = 6/group). Exposed groups received 7 h/day RF-EMF exposure for 60 consecutive days, while the Control underwent sham exposure. During the final week of exposure, mating behaviours were assessed using mount frequency, mount latency, intromission frequency, ejaculation latency, and post-ejaculatory interval. Serum testosterone and oestrogen levels, the T/E ratio and androgen receptor expression in the testis and hypothalamus were evaluated. The 3.5 GHz group demonstrated statistically significantly prolonged ejaculation latency (3480 ± 1576.956, p < 0.01, Hedges’ g = 1.03) compared with the Control group. In contrast, 24 GHz exposure statistically significantly reduced mount frequency (4.80 ± 0.837, p < 0.01, Hedges’ g = −0.65) and prolonged the post-ejaculatory interval (588.83 ± 206.41 s, p < 0.01, Hedges’ g = 1.63) compared with the Control group. Hormonal analysis revealed statistically significant elevation of testosterone levels in the 3.5 GHz group, whereas the 24 GHz group showed statistically significant reductions in testosterone and oestrogen. Androgen receptor expression was unchanged. These findings suggest frequency-dependent effects of 5G RF-EMF on male libido and endocrine balance.