Dihydrotestosterone (DHT)

Dihydrotestosterone, DHT for short, is a male sex hormone (androgen) that occurs in both men and women. Most of it is formed directly in the tissues where it acts: in skin, sebaceous glands, hair roots, prostate and liver. There, the enzyme 5α-reductase converts testosterone into DHT. In women it comes from testosterone and its precursors from the ovaries and adrenal glands. DHT is measured in serum. Because much DHT is formed and also used up in the tissue, the blood value only partly reflects the effect on site; it is therefore interpreted together with testosterone and SHBG.

What dihydrotestosterone does in the body

DHT binds much more firmly to the androgen receptor than testosterone and therefore acts more strongly. Unlike testosterone, it cannot be converted into oestrogen. Even before birth, DHT shapes the external male genitals. In puberty it makes beard and body hair grow, stimulates the sebaceous glands and controls the growth of the prostate. In adults it determines the sebum production of the skin and acts on the hair roots: on the body and in the beard it promotes hair growth, while on the scalp it can shrink the hair follicles in people with the corresponding predisposition. DHT is broken down mainly in the liver.

Low dihydrotestosterone – what happens in the body?

Low levels arise when little testosterone is available as a starting material or when 5α-reductase is less active. In men, an overall lack of male hormones can go along with declining libido, less body hair and lower muscle strength. Medicines that inhibit 5α-reductase and are used for an enlarged prostate or hair loss specifically lower the DHT level. Very rare is a congenital deficiency of the enzyme, in which the external genitals of boys do not develop completely. In women, low DHT levels are usually considered unremarkable, because they form only small amounts anyway.

High dihydrotestosterone – what happens in the body?

With a lot of DHT, the androgen receptors in skin and hair roots are activated more strongly. The sebaceous glands enlarge and produce more sebum, which favours oily skin and acne. In women, increased hair growth on the chin, upper lip, chest and abdomen as well as cycle disorders can occur. On the scalp, with a hereditary predisposition, the hair follicles shrink and the hair becomes thinner – in men at the temples and crown, in women rather along the parting. In older men, DHT drives the growth of the prostate. High levels occur with raised testosterone, for example in polycystic ovary syndrome, in which studies have also observed increased 5α-reductase activity, or with the intake of testosterone.

The interpretation is given in your report.