I have literally hundreds of positive anecdotes saved, in reference to using selegiline, but here’s one that’s really good, and in depth, where he mentioned how his orgasms became so much better on selegiline. So for once I’m actually posting something that’s related to the OP’s original question/ issue lol. And just for clarity’s sake, I think when he mentions that there’s no need to go over 1.25mg, I think he’s talking about taking that dose daily, and I think he’s referring to taking that dose sublingually. Sublingually, selegiline has a much higher absorption rate than taking it orally.
“Well for me the libido boost took a while to become really apparent. For me that effect has sort of accumulated over time too. I think your dose may be a little bit too high, if you take it daily there's no need to go over 1.25~ mg. At 2.5 mg daily you will most likely inhibit MAO-A to some degree and the increase in serotonin and norepinephrine can have the opposite effects on libido, especially serotonin. The prolactin reducing effect from Selegiline disappears when you start crossing into MAO-A territory a lot as serotonin has the opposite effect on prolactin compared to dopamine. I take like 1/4 of a pill now (about 1.25 mg) sublingually every 5th-6th day or so and this alone has a really big almost annoying increase in libido and sexual desire for me. Also orgasms feel so much better with MAO-B inhibited and for me they seem to last longer too, and when I was taking 1.25 mg daily it was really crazy as I would be getting multiple orgasms after coming once and it could last for like half a minute or so if not more. But if I take too much like 5 mg sublingual daily I in fact get greatly reduced libido and the complete opposite effects, and from what I remember when I was trying 2.5 mg/day I also had less libido than I had from 1.25 mg/day or the regime I am on now until my body maybe later adapted after a couple of weeks due to the increased serotonin I am guessing.
So try a lower dose imo, don't go over 1.25 mg/day and give it some time to see if it will have any "positive" effects on libido as the brain and body needs some time to adapt to these changes. In fact Selegiline seems to have made my testicles noticably bigger after some months of use now and that is a direct effect due to the lowered prolactin and increased dopamine (which in turn makes the testes produce more testosterone). Selegiline actually has this ability in male rats and mice too, where their testicles grew to a quite noticable level on measurements. So with this change made to testicles in mind and the effects I have had personally with a slowly increase in libido it sort of makes sense imo to give the brain and body some time to adapt and give it some time to see if it affects your libido or not.
And yeah when you start crossing into MAO-A inhibition territory that is also where you start crossing into the insomnia side-effect territory due to all the increase serotonin, noradrenaline and trace amines broken down by MAO-A greatly affecting and promoting wakefulness. Also this may suppress things like REM sleep and dreams, another huge downside in my own opinion. I would probably take selegiline daily if it were not for potentially crossing into MAO-A territory and getting many of these unwanted effects, also too much MAO-B inhibition just increases histamine too much for me personally.
And once again yeah, a lot of people just expect too much from Selegiline and think it will be some kind of strong amphetamine-like stimulant. People even like to talk about its amphetamine metabolites as if they could actually have any particular positive effects when they are the levo isomers which are pretty much only unpleasant and have so little affinity for anything else than norepinephrine that they are proven to have 0 abuse potential and addiction liabilites in animal studies lol.
Also I have never noticed any withdrawal symptoms from Selegiline. The effects from it are already very subtle and since the MAO-B enzyme is slowly and steadily recovered it is like a small self-taper is already built into the substance when you discontinue it(the dopamine and not to mention trace amine and PEA levels will slowly be going down as MAO-B activity increases). So I wouldn't worry about this. Almost nobody on the net has ever said that they experienced withdrawals from discontinuing it, and from what I remember animal and human studies showed that there was zero dependence developed on the substance”