A sudden change in animal behaviour caused concern in the 1940-ies. After long-lasting researches it was proven that it was caused by hormone disruptors; compounds which stop formation or block the transmission of hormones within the body and impair the condition of the organism. In interaction with hormones they have negative effect on the endocrine, reproductive, immune and the neurological system. Although in the beginning we weren't able to predict any negative effects of the compounds which we had synthesized, we didn't do anything to learn from our mistakes. We still produce tons of these compounds, although their molecule structures are obviously almost identical. Similar shape of a molecule obviously does not suggest to anyone that there might be similar action and interaction with hormones. Due to neglect of more than obvious facts, we allowed the chemical compounds to determine gender, behaviour and health of the individuals while still in the mother's womb. We allowed the birth of children under the influence of DES, DDT, phenol and many more hormone disruptors which are still recklessly released into the environment and entered into the organism. Today it is impossible to speak of a permanent solution since there are more than 100 000 synthetic compounds on sale and most of them are hormone disruptors. Currently, the most important thing is to broaden the knowledge and awareness of the compounds which can take away everything that makes us an individual, which is the main aim of this paper.