Grapefruit taken with the HRT may cause it to lose its effectiveness for a more chemical reason. Hormones given to livestock in meat and dairy products is forbidden here in the US. However, the meat I get these days says on the back that it is the product of the US, Canada, Mexico or Central America for the cheaper cuts. The ground beef has all 4 listed at times. The expensive "primo" cuts the stores sells as their top of the line do usually say it is a US meat item only. As for coming from Mexico or Central America, those places do not have the regulation enforcement the US and Canada have. That kind of hormone is a powerful synthetic type of the kind as the DES pregnant women in the 40's, 50's, and 60's were given to prevent miscarriages.
Joelene