Testagen is a short, bioregulatory peptide that has primary effects on the pituitary gland and ultimately the thyroid gland. As a result of its action on these two glands, Testagen is capable of normalizing testosterone production as well as thyroid hormone production in certain settings. By normalizing thyroid hormone production, Testagen has a moderate impact on the immune system. In these cases, Testagen can be conveniently thought of as resetting the pituitary gland to a more youthful state and thereby acting as an anti-aging peptide. Testagen is being researched for its ability to boost testosterone levels, improve thyroid hormone function, and stimulate the differentiation of stem cells in the immune system to improve immune function.