Are there long-term concerns about the use of domperidone?

The manufacturer states in its literature that chronic treatment with domperidone in rodents has resulted in increased numbers of breast tumours in the rodents. The literature goes on to state that this has never been documented in humans. Note that toxicity studies of medication usually require treatment with huge doses over periods of time involving most or all of the animal’s lifetime. Note also that not breastfeeding increases the risk of breast cancer, and breast cancer risk decreases the longer you breastfeed.