Could sex hormones explain the difference ... chronic pain in their paws gave themselves ever increasing doses of fentanyl over time, while female rats with the same chronic pain kept their ...

A study from the Institute of Environmental Medicine (IMM ... has clear negative effects on hormones and fertility endpoints relevant to female fertility. The results show that key reproductive ...

A new study in rats by researchers at Washington University School of Medicine ... themselves increasing doses of an opioid – specifically, fentanyl – over time, while female rats with the ...