Glycine for nocturia
The protocol is based on a 4-week human study where 3g glycine significantly reduced total urination, urgency, and nocturnal voids compared to placebo. Even when subjects did wake, the time to first void was extended. Thomas personally experienced a shift from waking at 1:30am to 4-5am, effectively sleeping through the night. He recommends combining glycine with magnesium (split dose) and fluid frontloading for maximum effect. The glycine should be taken in capsule form to avoid adding liquid volume that could counteract the benefit.
Glycine acts as a neurotransmitter, binding to NMDA receptors in the brainstem and suprachiasmatic nucleus, which calms the central nervous system and inhibits the micturition reflex. It also appears to modulate bladder nociceptors, reducing discomfort signals. This dual action delays the urge to urinate and allows longer uninterrupted sleep.
I am convinced that if I didn't have to get up to urinate in the middle of the night, I would probably sleep all the way through. ... my biggest issue is I almost always have to pee between 1:30 and 2:30 in the morning. ... if it could delay to 4 or 5 a.m. and I go to bed at 9:00, then I essentially made it through the whole night.
So, we're seeing that it suppresses the mcturan reflex. This essentially means that it's inhibiting some of the activity between the brain and the bladder, making it so that you don't have to use the restroom as much or have that sensation until you really have to go, not when it's just mild and waking you up.

