Almost same way they suggested to me. Mph helped with libido I got painful erections when I first stared but in long term there is no help for Ed it fluctuates with out any reason I just notice weird pattern.
If I am flaccid and masturbate I do not have any problems with sensitivity or satisfaction and I can ejaculate normally.
If I am hard with pde5 or naturally I lost sensitivity, archiving climax becomes very hard, orgasm pleasureless with weak ejaculation.
This got me thinking about HTR2A and HTR1A
Latter one inhibits erection and facilitates orgasm. First one does the opposite thing.
They might be trying to restore balance between them with mph and fibanserin