Scientific overview of hormone treatment used for rejuvenation.

A search for a hormonal fountain of youth has been hotly pursued over the last century, predominately by those who wish to market hormones to a gullible public. There is little or no benefit of hormone replacement in persons who do not have a hormone deficiency. Overall, the present state of the art suggests that the findings have been disappointing. In persons who fail to get adequate sunlight, and therefore have low vitamin D levels, vitamin D replacement appears to have positive effects, including decreasing mortality. Testosterone in hypogonadal males has a number of positive effects such as improving libido and erectile capacity, increasing strength and bone mineral density, and perhaps having a small effect on cognition. These effects need to be balanced against long-term side effects, the evidence for which studies are lacking. There is little evidence to recommend DHEA, pregnenolone, growth hormone, ghrelin, or melatonin to older persons. Overall, exercise, adequate exposure to sunlight, and adequate dietary protein appear to have at least as positive an effect as any of the hormones being used to rejuvenate older persons.