Long time insomnia sufferer here. Been taking zolpidem ER for several years now, but even with it, I sometimes cannot fall asleep at all. I also use 5HTP and magnesium glycinate.
I've recently added DSIP and Epitalon, while still taking a half a zolpidem to help with falling asleep. I tried epitalon first. Worked great the 1st day (300mcg), the 2nd day nothing. I added an extra 100mcg that same night and slept well. The next 2 days I did 400 mcg and the next day it didn't work. I added another 100mcg the next day and I slept better. The day after at 500 mcg didn't work again. I increased to 800 mcg on the following day and it was so so. I was at a loss, but thankfully the DSIP arrived. I pinned 100mcg the first night, ended up pinning another 100mcg and slept. The next night of 200 mcg was not so good - up for a couple of hours.
So I rethought my protocol and decided to cycle on and off epitalon/DSIP every other day. Epitalon still isn't working well, DSIP was doing better. Last night was epitalon time and again it didn't working so I got up around 2:00am and pinned a 100mcg of DSIP on top of the epi. Slept well the rest of the night.
It appears epitalon alone isn't the answer for me except when paired same day with DSIP. Still working on the protocol obviously. I will continue to take epitalon for the other benefits it provides and pin DSIP along with it for sleep. Crossing fingers for improved sleep.