I have posted on this before but generally related to cognitive effects of racetams eg piracetam, aniracetam, noopept. I have been using noopept off and on for awhile with only very mild effects on improving cognitive effects. What i did find was that urinary frequency greatly decreased. I mainly use it when i go to work as it reduces how often i have to run off to the loo. I do remember reading something about racetams possibly doing this but wasnt quite sure. My own testing/measuring showed my urine outflow is close to 10 litres a day, normal is 1 to 1.5L a day. I did have blood work on ADH and other electrolytes which werent too bad but i think i probably do ok hydrating myself and i have an ongoing thirst which possibly helps with keeping hydrated to a point. I spoke things over with my dr about using desmopressin which is used in diabetes insipidus, but he was hesitant and basically said my labs werent far enough out of range that he could prescribe this sort of treatment. Many mecfsers probably have similar issues to diabetes insipidus where they urinate all the time and this can have a big effect on orthostatic issues, especially if one doesnt have a great thirst and hydrates themselves properly. So last night after some research, it appears that the acetylcholine increases from racetams, can help regulate the autonomic nervous system/parasympathetic nervous system which regulates urination and digestive function. It appears that acetylcholine increases vasopressin/ADH and this could be an alternative to drugs/hormones such as desmopressin. So those with hypotensive POTS it may be worth trying and cautiously with those who have hypertensive POTS and possibly could help some who have digestive issues and bowel function. Many mecsfers have issues with constipation and diarrhoea, its possible this may help, although i dont have any personal experience on that side of things. I would be interested to hear from others who have noticed any of these effects from racetams or who try them down the track. cheers!!