 Peripheral precocious puberty caused by exogenous estrogens is evaluated by assessing decreased levels of gonadotrophins.Hormones or substances with hormone disrupting capability, such as the xenoestrogens in plastic, packaged,food and drink trays and containers, ( more so, when they've been heated in the Sun, or an oven ), may interfere with pubertal development by actions at different levels – hypothalamic-pituitary axis, gonads, peripheral target organs such as the breast, hair follicles and genitals.Exogenous man made chemicals that mimic estrogen can alter the functions of the endocrine system and cause various health defects by interfering with synthesis, metabolism, binding or cellular responses of natural estrogens.