Table 1.

Rhythmicity and physiological effects of hormones in male and female fertility.

Hormones	Rhythmicity		Effects on Male	Effects on Female
FSH	24 h circadian rhythm during follicular phase [25]	24 h circadian rhythm during luteal phase [25]	Sertoli cell tropism and sperm production [20]	Stimulation of estrogens production by ovarian granulosa cells [22]
LH	24 h circadian rhythm during follicular phase [25]	No circadian rhythm in luteal phase [25]	Stimulation of testosterone production by Leydig cells [21]	Stimulation of estrogens production by ovarian granulosa cells [22]
				Regulation of theca cells androgen production [26]
Estrogens	24 h circadian rhythm during follicular phase [25]	No circadian rhythm in luteal phase [25]	Regulation of ductal and epididymal function [27]	Development and maintenance of secondary sexual characteristics [28]
Androgens	24 h circadian rhythm with a peak in the early morning [26]		Development and maintenance of secondary sexual characteristics [29]	Control of growing follicles [30]
Glucocorticoids	24 h circadian rhythm with a peak in the morning [31]		Promotion of sperm maturation and steroidogenesis [32]	Regulation of fetal growth and development [33]
Melatonin	24 h circadian rhythm with a peak in the night [34]		Preservation of spermatogenesis [35,36]	Control of neurological and endocrine systems development [37]
			Reduction of free radicals protecting sperm from oxidative damage [35,36]	Protection of the embryo/fetus from metabolic stress [37]