Students who take melatonin supplements to help them sleep could worsen a condition in which the body cannot maintain enough blood flow to the brain when a person stands.

The study that made this connection was done by Chester Ray, associate professor of medicine and cellular and molecular physiology at the College of Medicine. It was published on Sept. 15 in London's Journal of Physiology.

Melatonin is a hormone secreted at night by the pineal gland in the brain. Generally, people who experience jet lag or have trouble sleeping take melatonin supplements. Although non-herbal sleeping aids are still more commonly used for sleeping trouble, melatonin use is widespread.

Some pharmacists say many people take melatonin over sleep aids because sleep aids sometimes produce a hangover affect or "medicine head," which makes people feel groggy in the morning.

Cassie Massacker (sophomore-kinesiology) said she would rather not take any kind of medication or supplement to help her sleep because she doesn't want to become reliant on a product.

"I've taken Tylenol PM and NyQuil when I'm sick," she said.

Pharmacists say melatonin is considered an herbal medicine that can be found in teas and other natural products. In contrast, sleeping aids sold in the over-the-counter medication aisle of a pharmacy do not contain melatonin, but an antihistamine with sedative properties.

The study at Penn State concerns people with orthostatic intolerance, in which the cardiovascular system cannot maintain enough blood flow to the brain when a person stands. As a result, this condition induces dizziness and fainting. Ray said this condition is not vertigo, which may also cause dizziness.

"If someone is predisposed [to having orthostatic intolerance], taking a melatonin supplement may exacerbate the problem," said Ray. Mainly women and the elderly are diagnosed with orthostatic intolerance, and scientists don't know why women are more likely than men to have it.

Twelve healthy subjects, five men and seven women, in the age range of 25 to 27 years volunteered for this study. During the experiment, each person was given 3 milligrams of melatonin. After 50 minutes, the subject was introduced to an orthostatic challenge, which in this case was simulated using a chamber that sucks out air and pulls blood to a person's legs.

It mimics the act of standing up from a seated position. Ray said this orthostatic challenge is beneficial for taking measurements because the subject does not move around.

The results were measured by inserting a needle into a subject's knee. It allowed researchers to look at the "nerve traffic that travels from the brain to the blood vessels," said Ray.

Subjects were given both a placebo and melatonin to verify that melatonin actually played a part in decreased nerve activity.

The results indicate that the subjects' nervous systems were less responsive when given melatonin. However, researchers do not yet know just what parts of the body could be affected by the lower nerve response.

Some students may still use the herbal supplement regardless of the effects it may have.

When asked what he would use for sleeplessness, Aaron Yorkonis (sophomore-civil engineering) said he would "probably take a supplement that the body actually produces" over a non-herbal sleep aid.

Tam Tran (sophomore-premedicine) said that she has never taking a sleep aid. "I think the problem most students have is staying awake."