Clistilbegyt and Aromek are prescription drugs, their use during breastfeeding or returning to breastfeeding after the end of treatment with these drugs is decided by the doctor ordering their use. According to currently available knowledge, there is a low risk of clomiphene (the active substance of Clostilbegyt) passing into breast milk. With letrozole (the active substance Aromak), this risk is very high. Data on the return to breastfeeding after the use of Arome are undressed, experts suggest resuming feeding after 10 days (this is the time after which letrozole is completely eliminated from the body), one of the manufacturers (Novartis) after 21 days. Therefore, in order to accurately determine the time after which breastfeeding can be resumed after the end of treatment with Letrozole and Aromek, it is best to contact a doctor or lactation counselor. I enclose information about the possibility of using teleconsultation: https://www.gdziepolek.pl/telekonsultacja We wrote more about the use of drugs during lactation here: https://www.gdziepolek.pl/artykuly/leki-a-karmienie-piersia