Your body, via the pineal gland, naturally produces this hormone, which is responsible for regulating your sleep-wake cycles. Ideal for short-term use, and often taken by those experiencing insomnia or jetlag, melatonin may have side effects that include nausea and headaches if the dose is too high. Starting with a small dose and increasing as necessary will allow you to make the most of this supplement.
GABA (gamma-aminobutyric acid)
This is the amino acid responsible for regulating the nerve activity in the brain, and low levels of it can inhibit deep sleep.
Known to promote relaxation and deep sleep, this supplement can be taken either as a tea or capsule. It is known to increase GABA levels.
Another sleep-promoting amino acid, a 500 mg supplement can maintain serotonin, which plays a role in regulating sleep.