BUT melatonin does not cross the blood brain barrier when taken as a pill or capsule. (fransussman.com)
As they easily cross the blood brain barrier with the potential for neurological damage, they are best avoided. (it-takes-time.com)
Less leptin crosses the blood brain barrier, less binds to its receptors and the brain sends the signal to let you know it's time to eat again. (onketosis.com)