All SSRIs seem to cause sexual dysfunction, yet there is some variation within this class of drugs. Prozac is the worst SSRI for libido, decreasing it in 11% of its. Fluoxetine can have side-effects that might affect your sex life. The good effects of fluoxetine may, after a while, have a good effect on your sex life as your mood lifts and you become interested in life and relationships again. Some of the possible negative side effects include: You may have a lower sex drive.