derivatives

Derivatives of female sex hormones can influence natural melanin production, study suggests When skin cells responsible for pigmentation are exposed to estrogen or progesterone, the cells respond by adjusting their melanin production, resulting in either skin darkening or lightening. Although...

What is the difference between the two? And, are these the same as methytren? And are methyltren, methyltrienolone, Dimethyltrienolone all tren derivatives?