Background: After having returned from China for more than 10 days, I still felt tired. Sure, it could be due to the fact that I am old. Still, I wanted to try to improve the quality of my sleep, so I took 3 mg of melatonin at 9:30 pm and as expected I felt sleepy around 10 pm. What surprised me was that I woke up at 7 am sharp, without an alarm. This happened twice in a roll, and I could tell I was less tired during the day. Guess what I decided to do on the third night...

According to wikipedia, hormones have the following effects on the body of mammals:

• stimulation     or inhibition of growth

• mood     swings

• induction     or suppression of apoptosis (programmed cell death)

• activation     or inhibition of the immune system

• regulation     of metabolism

• preparation     of the body for mating, fighting, fleeing, and other activity

• preparation     of the body for a new phase of life, such as puberty, parenting,     and menopause

• control of     the reproductive cycle

• hunger     cravings

• sexual     arousal

A hormone may also regulate the production and release of other hormones.