Which natural (herbal, greens) products available that help improve brain power and memories?

Sleep. Brain function can be related to sleep. If you are not getting 7-9 hours of good sleep or if you have excessive daytime sleepiness than you may have a sleep related breathing disorder that is affecting you brain function. Herbs and natural products can be helpful but nothing can replace a good nights sleep. If you have poor sleep see you md for a sleep evaluation.