Will curcumin help with sleep?

Only as placebo: If anything, curcumin is a stimulant - so unless you mean to help you sleep less - it is very unlikely. Actually, from my knowledge on curcumin, the stimulant effects are more organic - in digestion ; reproductive systems anyway. So, it might not actually keep you awake either. Best!

Cucurmin effects: Cucurmin is an anti-inflammatory supplement that works like NSAIDs and is good to help calm inflammatory conditions such as arthritis. There is no current medical literature on my search that shows a relationship between cucurmin and sleep. I suppose if you are unable to sleep because of pain from arthritis, cucurmin may help improve the pain and thus help you sleep.