Lambda-cyhalothrin and male reproductive dysfunction: neurotoxicity, hypogonadism, erectile dysfunction, and infertility.

Lambda-cyhalothrin is one of the most widely used type II pyrethroid insecticides in agriculture, public health programs, and domestic pest control. Although their acute toxicity in humans is generally considered low, concerns have been raised regarding their potential effects on male reproductive function. Male infertility affects a substantial proportion of couples worldwide, and environmental exposures have been proposed as contributing factors. This review critically examines the available evidence linking lambda-cyhalothrin exposure to male reproductive dysfunction. Experimental studies have reported adverse effects on neurotoxicity, reproductive hormone regulation, testicular function, spermatogenesis, and sperm quality following lambda-cyhalothrin exposure. Human studies have identified associations between urinary pyrethroid metabolites and reduced semen quality, altered reproductive hormones, and sperm DNA damage. However, the available epidemiological evidence remains limited and heterogeneous. Current findings indicate that lambda-cyhalothrin may adversely affect male reproductive function through neurotoxicity, endocrine disruption, oxidative stress, impaired testicular function, and sperm damage. While the biological plausibility of these effects is supported by experimental data, the extent of their contribution to infertility in exposed human populations remains uncertain. Unlike previous reviews, this review proposes an integrated neuroendocrine framework linking central, autonomic, and peripheral neurotoxicity with hypothalamic-pituitary-gonadal axis dysfunction, hypogonadism, erectile dysfunction, and male infertility following lambda-cyhalothrin exposure. This integrated perspective highlights important evidence gaps and may guide future experimental, occupational, epidemiological, and clinical research.