Does human growth hormone (HGH) have anti-aging properties or does it contribute to heightened cancer risk and earlier death? The complex science in the area suggests the answer is yes to both, the Wall Street Journal reports.

HGH, which helps stimulate cell growth and division, is given to slow-developing children and teens to increase their growth. But healthy older individuals also are taking it to improve the appearance of skin, increase muscle tone, and for other purported benefits.

The global market for HGH is estimate to reach $4.7 billion by 2018, but new studies published this year suggest that lower levels of an HGH-related compound called insulin-like growth factor-1, or IGF-1, are related to longevity and lower risk of cancer as people reach old age.

"These studies suggest that growth hormone for healthy aging might not be a good idea," Nir Barzilai, an endocrinologist at Albert Einstein College of Medicine in New York City who published one of the papers in the publication Aging Cell , told the Journal.

Levels of testosterone, estrogen, growth hormone, and other biological chemicals fall with age, but whether replacing or supplementing hormones is good for the health of an aging individual is a complex question.

The Food and Drug Administration has approved many synthetic growth hormone products for treatment of people who need more in their systems. But since 2010 the agency has monitored people receiving treatment due to data suggesting that adults who were treated with HGH during childhood had a 30 percent increased risk of early death compared with the general population.

The FDA continues to believe the benefits outweigh the risks in that population, according to its website.