The conductor of the endocrine system is the anterior pituitary gland, nestled at the base of the brain. The hypothalamus sends special hormones called releasing factors to the pituitary instructing it how to manage the other endocrine glands. Then with its own set of directive hormones, the anterior pituitary guides your body's glands. The anterior pituitary also releases prolactin, a breast feeding hormone, and growth hormone.

The posterior pituitary, a neighbor but unrelated to the anterior pituitary, is responsible for two hormones: antidiuretic hormone and oxytocin. ADH helps you maintain arterial blood pressure during, for example, blood loss by resorbing water from your kidneys. Oxytocin contracts the uterus during childbirth and causes milk letdown during breast feeding.

Each endocrine gland plays a distinct role in your body, but these actions overlap and therefore affect one another too. When one gland is overly or under-active, other glands feel the effect. The same goes for you. When part of your endocrine system is sick, you most likely are too. Fatigue is one symptom that many endocrine disorders have in common. If you feel very tired or can't seem to shake your fatigue, see your doctor. Once you've discovered the source of your fatigue--whether it's endocrine related or not--there are many natural remedies you can try under the guidance of a professional.

Function
Although part of the endocrine system, the pineal gland isn't a gland per se. This neuroendocrine body translates nerve messages into hormonal output--namely melatonin. This pineal hormone peaks in your body around midnight. Babies are born with scarce amounts of melatonin, perhaps accounting for their erratic sleeping habits. Levels, however, rise with age, top out in childhood and then slowly decline with years.

The pineal gland and melatonin are thought to keep your biological clock ticking. External cues like temperature and light, as well as endogenous messages such as emotions guide the pineal gland. In this way sleep, mood, immunity, seasonal rhythms, menstruation and even aging are regulated.

Melatonin
Synthetic versions of melatonin have recently been touted as nature's new wonder cure for fatigue, insomnia, depression, jet lag, cancer and old age. During her lecture on melatonin at a recent naturopathic medical convention in Aspen, Colorado, Anna MacIntosh, PhD, ND agrees this hormone appears to be a cure-all. That's also what frightens her.

Although supplemental melatonin doesn't seem to have toxic effects, it shouldn't be used indiscriminately. There's too much we don't know about this hormone yet, says MacIntosh. We don't know its long-term repercussions and whether it exerts subtle, and as yet, unmeasured effects. Because melatonin governs biological rhythms, will overuse or ill-directed use adversely affect you?

Melatonin is probably safe for insomnia and jet lag. If you decide to take melatonin, don't take it during the day--this will only aggravate your fatigue and sleeping problems. Instead take melatonin one hour before sleep. Better yet, preserve your own melatonin reserves by sleeping in a dark room, not turning lights on if you get up in the middle of the night and don't take ibuprofen late at night.