It's not just women either. My DH is in his 50s. I've made clear to him that I am not prepared to carry all the mental load for our sex life. I need HIM to bring up the topic of sex for discussion. I'm sick of having to be the one to solve any problems. I have no idea what is going on in his head. I think he's uncomfortable bringing it up, but he's going to have to overcome that if he wants any sex. If I feel like I have to be the one to work for it all the time, it's just not appealing. I'm done with that dynamic.
From his side, he's had some health issues, so there may be some anxiety and issues in that. He's on cholesterol medication, which I know can lower his libido. He needs viagra, which he probably has concerns about with his own health issues. This kind of situation needs communication. He's not good at that and I'm not going to be the initiator yet again.
There's also the issue that he thinks he can do nothing about it for several months, my mind is just not there, and then all of a sudden, "Are you interested in sex tonight?" said at 11pm. Then I'm expected to flip a switch. It doesn't work that way and I've told him that.
I'll consider sex when he shows he cares enough about it to overcome his discomfort with the topic and talk about what's actually going on for him. Meanwhile, I have enough other things that drain my energy going on. He brings it up, sex is a possibility. He sits on it and does nothing, I'm doing nothing. In fact, I'm becoming quite happy and more and more happy with the current situation and not having sex.
Then again, as a result of medication or anything else, maybe he's actually not interested and doesn't want to say? Personally, I'd rather he did say so I know where I stand. If he waits too long, there may be no going back.