Dihydrotestosterone (DHT) is a metabolite of testosterone and also belongs to the group of male sex hormones, the androgens. In the following article we will explain the connection of DHT and hair loss, why DHT causes hair fall and how to block DHT in order to prevent hair loss.
What is dihydrotestosterone (DHT)?
DHT is a modification of the hormone testosterone in its most biologically active form. The enzyme 5-alpha-reductase is responsible for this. It triggers a chemical reaction that converts testosterone into DHT. The effect of DHT is actually positive: it is important both for the development of the male embryo and in puberty for the transformation from boy to man. Here it is responsible for beard growth and general male body hair. DHT is also involved in the function of the sebaceous glands and the development of the prostate. To a small extent DHT is even found in women.
How is DHT produced and how does it work?
DHT is produced from testosterone in the target organs such as the prostate, seminal vesicle and epididymis. More precisely, a reduction of testosterone takes place through the enzyme 5α reductase.
Like testosterone, DHT can also inhibit GnRH release in the hypothalamus through a negative feedback mechanism and thus reduce the production of testosterone and DHT. The standard values for DHT are 0.16-1.10 ng/ml for men and 0.06-0.2 ng/ml for women.
Dihydrotestosterone standard values
- Men: 0.16-1.1 ng / ml
- Women: 0.06-0.2 ng / ml
The majority of DHT is bound in the bloodstream to sex hormone-binding globulins (SHBG). Only 1% of DHT circulates freely in the blood.
Like testosterone, free DHT can bind to androgen receptors in target organs. In the inactive state, androgen receptors are bound to heat shock proteins that stabilize the receptors in the cytoplasm of the cell. When DHT binds to the androgen receptor, a conformational change is induced that causes the release of the heat shock protein and the translocation of the hormone-receptor complex into the cell nucleus.
There, the complex can bind to so-called “androgen-responsive elements” of the DNA in the form of dimers, i.e. two hormone-receptor complexes, and regulate the expression of androgen-dependent genes. The effectiveness of this DHT effect also depends on so-called coregulators, which can have an activating or repressive effect on gene expression by binding to the complex.
Interestingly, the mode of action of DHT and testosterone is identical, but DHT is a more potent androgen because it has a higher affinity to the androgen receptor and can therefore act more effectively.
What functions does DHT have?
As the male sex hormone, DHT is primarily responsible for the formation and functionality of the male reproductive organs.
During embryonic development, the specific functions of DHT include the development of the penis, the scrotum and the prostate. During puberty, DHT promotes the growth of the male reproductive organs and male body hair as well as increased secretion of sebaceous glands. In adulthood, it is involved in the formation of prostate and seminal vesicle secretions. In addition, DHT shows gender-unspecific anabolic effects on muscles, bones and the haematopoietic system.
In addition to the reproductive organs, 5α reductase is also expressed in the liver, kidney, skin and brain, but the specific functions of DHT in these organs are not yet known.
Which medical conditions are related to DHT?
DHT is formed by the conversion of testosterone by the 5α reductase. Various medical conditions based on a reduction or overproduction of DHT can therefore be attributed to congenital defects of the 5α reductase. For example, 5α reductase deficiency can lead to the development of hermaphroditic genitalia and intersexuality. However, during puberty, normal penis growth and normal testicular development and spermatogenesis can be demonstrated. However, the prostate is only rudimentarily developed in these patients and reduced body hair is observed.
In addition to 5α reductase deficiency, excessive 5α reductase activity can also have negative effects. A correlation of 5α reductase activity with prostate enlargement and hair loss in men has been demonstrated.
Due to the positive correlation between DHT and prostate development, 5α reductase inhibitors (finasteride and dutasteride) have been developed for the treatment of benign prostate hyperplasia and the effect on prostate carcinomas has also been investigated. Here, therapy with 5α reductase inhibitors showed a reduction of up to 25% in the incidence of prostate carcinomas compared to patients treated with placebo.
DHT blocker for hair loss
In congenital hair loss (androgenetic alopecia), the hair roots react hypersensitively to a metabolic product of testosterone, a hormone found in both men and women. This metabolic product, called dihydrotestosterone (DHT for short), ends the hair’s life cycle prematurely in the case of a hereditary predisposition: the hair root atrophies and is eventually unable to form hair. The hair becomes thinner and thinner and smaller until bald spots appear.
DHT and hair loss
For men, but also for women whose hair roots are sensitive to DHT due to a genetic predisposition, DHT has a negative effect as soon as it docks on the hair follicles in the scalp:
- The growth phase of the follicles is shortened and the resting phase is prolonged (see also hair cycle).
- The hair follicles shrink until they no longer produce new hair.
- The capillaries leading to blood are narrowed, which means that the follicles are no longer sufficiently supplied with nutrients.
So the hair formation is inhibited. Regrowing hairs become thinner and thinner, until finally even the hair root atrophies.
The DHT effect can also be noticeable in women. The female sex hormone oestrogen naturally protects against the damaging DHT effect for a long time. However, if the oestrogen level falls as a result of a change in the hormone balance, for example during pregnancy or breastfeeding, during menopause, when taking the pill, the hereditary predisposition can become noticeable (see also hair loss women).
Herbal DHT blockers
Some natural DHT inhibitors can lower DHT levels.
- Sulforaphane (mustard oil glycosides)
Sulforaphane belongs to the so-called isothiocyanates. Sulforaphane is found in broccoli, all cabbage vegetables, cauliflower, kohlrabi, horseradish, rocket, cress, radish, radish, mustard and many other vegetables from the crucifer family.
- Theaflavin (black tea extract)
Theaflavins belong to the group of polyphenols and are formed during the fermentation of green tea to black tea. They are therefore contained in black tea.
- Fenugreek seeds
The active ingredients trigonellin and diosgenin in the seeds of fenugreek are said to inhibit DHT. Fenugreek seeds are mainly used as a spice.
In the outer layers of flaxseed there are the so-called lignans – secondary plant substances that belong to the group of phytoestrogens and are supposed to inhibit DHT.
So if you enrich your diet with natural DHT blockers, you can already counteract hair loss in mild cases – especially if it is still in its early stages.
Since DHT is the cause of the hereditary hair loss, it is important that the preparation has a targeted effect against DHT. Here, the active ingredient alfatradiol has proven its worth.
The active ingredient alfatradiol is a modified form of the female sex hormone 17β estradiol. However, it does not act like an oestrogen in the body and therefore does not interfere with the body’s own hormonal regulation.
Alfatradiol inhibits the aforementioned 5-alpha-reductase, which converts testosterone into DHT. It can therefore reduce the conversion of testosterone into dihydrotestosterone in men and women and thus reduce the harmful DHT effect directly at the hair root.