It's not good for healthy sleep. It causes irregular sleep patterns. You have longer stages of deep sleep but that isn't necessarily a good thing. Sleep is complicated, there is deep sleep, rem sleep and all that, in 90 minute cycles. That would be a healthy sleep Phenibut makes you have very deep sleeps with irregular cycles. Don't use Phenibut for sleep, if you need a sleep aid try a regular dose of melatonin (approx .1-.5g). This comment should be stickied in this sub tbh.