For the last 6 days I have been taking intranasal insulin, with daily doses starting at 5 IU, going up to 20 IU (which is the highest dose I have tried so far).
I am using it intermittently (taking it one day, but not the next day) to see if there are differences in my cognition between the days I take it, and the days not taking it.
So far I am not sure if intranasal insulin is having much effect. It's possibly increasing motivation and mental focus, but there are no obvious "Wow!" effects from taking it; if it is doing something for me, I think it is relatively subtle.
However, I will keeping on experimenting with it over the coming weeks, again on an intermittent basis, and see how it goes. I'll probably try doses up to 40 IU. I am not getting any side effects at all from intranasal inulin, so I feel confident in trying higher doses.
Because I am currently in the middle of testing another ME/CFS treatment regimen, I don't want to take intranasal insulin full time, because then I would not be able to work out which regimen was providing benefits, if benefits appear.
But because the action of intranasal insulin is short-lived (the effects of one dose last for around half a day), I can take it now and then, without interfering with my other longer term regimen.