What happens next in this paragraph?

How to take melatonin
Know how melatonin works.
Melatonin is a natural hormone produced by your pineal gland located in your brain. It acts like a neurotransmitter, or chemical messenger, to activate certain pathways in your brain.
Its role in establishing a sleep cycle has been recognized; however, recent research indicates it may be involved in other body functions as well. In the usa, melatonin is available over-the-counter as a dietary supplement and is therefore not regulated by the fda.