The short version: if oxytocin was effective for libido, it would have been all over internet by now.
In 2015-2019, Amazon used to sell an Oxytocin Nasal Spray (OxyLuv). I used it to help me reach orgasm (2-3 pumps per nostril, each pump = 10 IU, 1 hour before sex) and it worked for that in 2015. It is not clear how exactly it worked but there was some article that nasal oxytocin leads to release of adrenaline. Later in 2016, using the spray started impairing erection, which again could be explained by adrenaline release. In 2018, the same OxyLuv bought again from Amazon was not working for orgasm at all - either the 2018 spray did not contain actual oxytocin or it degraded in Amazon storage. I bought another OxyLuv spray from Amazon in 2019 and this again worked for orgasm but suppressed erection.
Apart from the positive effect on orgasm, and negative effect on erection at the end, I did not notice any significant effect on libido, social anxiety, or depression, apart from some placebo. It did seem to relax me a little some time after spraying in the nose but the tiny magnitude of the effect was not worth pursuing.
