Im taking massages sometimes, am I allowed to use a female massage therapist?
It is not permitted to do. The reason is because the massage is going to cause inappropriate thoughts to the man. (Besides that the unfortunate facts are that it will lead to things a lot worse).
However according to some authorities if the massage is warranted by a doctor, and done in a medical facility, by a medical licensed professional, and there isn’t any other male therapist then it would be permitted.
Chut Shani 4 pg 404,Nafshei Bsheilosi (Lugasi) 3 pg. 400, Taharas Herayon Vleida Kalah pg 304 in the name of R’ Yitzchok Yosef shlit”a, Aseh Lecha Rav 9-27