Diets and Supplements
Anti-aging research focuses on nutrition—diets or supplements to extend lifespan. Supplements that have been reported to extend the lifespan of rats and mice, includes the minerals selenium or zinc, though none has been proven to do so in humans, and significant toxic effects were observed. Metformin may also extend life span in mice.
The anti-aging industry offers several hormone therapies. Some of these have been criticized for possible dangers to the patient and a lack of proven effect. For example, the American Medical Association has been critical of some anti-aging hormone therapies.
The evidence for use of growth hormone as an anti-aging therapy is mixed and based on animal studies. An early study suggested that supplementation of mice with growth hormone increased average life expectancy.