Yup..that's exactly what I was thinking. I'm a male on Trintellix 15mg and I haven't had any sexual side effects, however that study using the Arizona Sexual Experience Scale that @metamorphosis quotes shows higher incidence among female participants. So maybe that's what's going on for you.

If 5mg is still giving you trouble, probably best to switch. I've found Trintellix great for me, but as we know, everyone reacts differently to these chemicals.

Good luck!