(I wish I had known this when I was a teenager!)
This effect is especially marked with citalopram, which is actually well-known for its absence of other side-effects.
This should be made public (among doctors) with regard to treatment of sexual criminality dispositions (libido suppression is currently achieved by hormone treatment, having breast growth as side effect in men)!
I use clomipramine in high doses (375-450 mg; bloodrates to about 2100 µg/l) resulting in being totally free of sexual fantasies and longings. Yet, the libido-suppression is already clearly noticeble at a dose of just half a tablet (37,5 mg)!
Even when actually getting a chance to make love, this doesn't hinder at all. The possibility of getting aroused when one actually wishes, turns out not to be compromised.