The Testosterone metabolite, DHT: Not as bad as we thought? Testosterone metabolites and their two derivatives, Dihydrotestosterone (DHT) and Estradiol (E2), are receiving much attention in the Andropause field. Testosterone levels decline with age but not all men suffer from Testosterone deficiency symptoms. Also, Testosterone treatment is only effective for a subset of the Testosterone-deficient population. The clinical features of Testosterone deficiency include diminished libido, erectile dysfunction, fatigue, mood changes such as depression and anxiety, cognitive complaints such as poor concentration and memory difficulties and decrease or loss of lean muscle mass and an increase in body fat which may lead to obesity. It was realized some time ago that Testosterone is not the entire story. Testosterone deficiency may be secondary to other hormonal deficiencies such as Thyroid, Progesterone and Estradiol (E2). Testosterone can be converted into estrogens by two enzymatic pathways: by aromatase in peripheral tissues such as fat and skin or within the central nervous system and Testosterone can also be metabolized into Dihydrotestosterone (DHT) and Estradiol (E2) by 5-α reductase enzymes either at the Testosterone receptor site or outside of this binding site. These metabolites have been implicated in negative effects on prostate health but more significantly they seem to inhibit cognition memory, energy levels and sexual function. Testosterone can also be converted into DHT within the Testes, seminal vessels and prostate. Testosterone is the major sex hormone in males responsible for maintaining sex drive or libido, physical health including muscle mass and bone density, fat distribution around the trunk of the body, moods and cognitive functions.
DHT has been implicated as a bad actor with possible links to hair loss (baldness) , benign prostatic hyperplasia (BPH), acne, seborrhea, pattern hair loss known as Androgenetic Alopecia or common baldness in susceptible men who are genetically predisposed to this disorder plus many other suspected deleterious effects on male physiology yet Testosterone is not without its risks either. Testosterone is now so widely used as a Testosterone replacement therapy (TRT) that it has become very clear that Testosterone can also cause certain side effects. Testosterone and its metabolites (DHT and E2) play an important role in the development of male secondary sexual characteristics such as body hair, muscle mass, testicular growth and sex drive or libido. Testosterone does not directly influence facial hair growth but it stimulates increased sebaceous gland activity which increases production of oily sebum which subsequently promotes acne (acne vulgaris). Testosterone has several beneficial effects for cognition, memory and mood but if Testosterone levels are too high or too low then these benefits may be overwhelmed by significant adverse events such as depression or aggression.