Human growth hormone (HGH) is a potent natural substance produced by the pituitary gland of the brain. While it has numerous beneficial effects in adults, including increasing metabolism, improving muscle tone and stimulating fat loss, enhancing strength and improving the function of the immune system, inappropriate levels of human growth hormone can also lead to various deleterious effects.

While excessively high levels have equivocal effects in children, in adults the side effects of HGH are grouped under the medical term "acromegaly." Acromegaly is the unrestricted growth of tissues of the body, causing coarsening of facial features, excessive enlargement of the hands and feet, and bone deformation. In the facial area, the tongue may enlarge, gaps in between teeth may increase, and the lower jaw may grow, causing an overbite and headache. In addition, another side effect of HGH elevation is the inappropriate growth of facial hair and a deepening of the voice, in women as well as men. Furthermore, individuals who have acromegaly generally note coarsening and thickening of the skin, and the appearance of what are known as "skin tags," or benign (but cosmetically problematic) growths in many areas of the body. In addition, many sweat excessively, even at rest.

Finally, because HGH promotes the growth of many bodily tissues, recent research has revealed that it can increase the risks for developing benign growths and polyps. This includes uterine tumors in women, and colon polyps in individuals of both genders.

If left untreated, acromegaly leads to serious health problems such as heart disease, diabetes, and arthritis. All of these are potential side effects of HGH when its levels in the body are chronically elevated.

Although acromegaly is naturally very uncommon and only caused by rare tumors of the pituitary gland in the brain (the tissue that secretes HGH), it can also be caused by inappropriate administration of synthetic HGH, also known as somatrophin. Because synthetic HGH is introduced directly into the bloodstream, the body is unable to regulate these levels. Consequently, these side effects have thus been found in some individuals (e.g. athletes) who use HGH inappropriately.

Despite all of these potential problems, the positive effects of HGH, as described at the beginning of this article, are so impressive that significant research efforts have been made to safely increase levels of HGH in the body to allow individuals to harness its benefits. A new class of nutritional supplements, the growth hormone secretagogues, coaxes the body's pituitary gland into releasing internal stores of HGH. Because this HGH is released by the body itself, it is subject to robust regulation systems, which prevent its levels from rising to harmful levels. As a result, leading HGH secretagogue products, such as Sytropin and GenF20, are safe, effective, and free of any of the negative side effects of HGH. They are now being commonly used by adults in all states of health to safely and effectively improve their well-being.