Dihydrotestosterone is a metabolite for testosterone. It is similar to testosterone, but has stronger effects. DHT is three to six times stronger than testosterone. Both hormones can be classified as androgens. DHT is created primarily in the organs that it is used, like the prostate. DHT is converted to testosterone by the enzyme 5-alpha reductase.
It is interesting to note that testosterone and DHT both bind the same receptors. DHT does this more efficiently. DHT binding also has different responses. The body binds most of the DHT to proteins in the blood, including albumin and sexhormone binding globulin. The same holds true for testosterone. DHT is less than 1% of the hormone that circulates freely in the blood. This is slightly less than the percentage of testosterone that is bound or free.
Although albumin can bind large amounts of testosterone and other sexhormones, it does so very weakly. The Sexhormone Binding Globulin, on the other hand, binds more hormone but less strongly.
10’000 Hours / Getty ImagesDihydrotestosterone has a number of effects on the human body. It is a precursor to other steroid hormones and serves as a stronger testosterone form.
It can also lead to hirsutism or female pattern baldness. In contrast, a lack of DHT production can cause differences in sexual differentiation like androgen insensitivity syndrome.
Different organs have different significances for dihydrotestosterone. DHT levels that are too high can be problematic in certain areas of the body. However, it is essential in other areas.
DHT stimulates two types of cell growth in the prostate: epithelial and stromal cells. DHT can be combined with estrogen to increase prostate size. Older men are more likely to have estrogens, which increase the number hormone receptors in their prostate. DHT is more effective in promoting prostate growth when there are more hormone receptors.
DHT is often associated with benign prostate hyperplasia (BPH). BPH can lead to symptoms like difficulty urinating and the need to urinate more often, as well as other issues. Finasteride, a drug that lowers DHT levels, can be used to treat DHT-induced prostate growth. Finasteride acts as a 5-alpha-reductase inhibitor.
Male Pattern Baldness
For hair-growth patterns that are associated with puberty, androgens are essential. But not all hair follicles respond to androgens the same. An excess of DHT has been linked to male pattern baldness and beard growth. Anti-DHT medication can be used to increase hair growth in the scalp for men suffering from male pattern baldness.
It is interesting to note that testosterone seems to stimulate pubic hair growth and underarm hairgrowth more than dihydrotestosterone.
Overproduction of DHT may be the reason women experience more facial and body hairs. It is possible to reduce unwanted hair growth by blocking DHT, even though it can seem confusing. This can often be done using the same drugs that are used to increase hair growth in balding men.
What is the reason why the same drug can have opposite effects? This is because the hormones that affect hair follicles are different in each region of the body. Hair loss in women may be caused by hormonal problems (androgenic hair loss). This can also be treated with the same drugs.
DHT and Sexual Development
DHT is not only important for general health, but also has many effects on sexual development.
DHT is particularly important in the development and maintenance of male external genitalia.
Due to 5-alpha reductase deficiencies, XY-infants do not produce DHT and are therefore born with ambiguous or feminized reproductive organs.
Some forms of DHT deficiency that affect only one of the five-alpha reductase enzymes may cause puberty to reverse, but these cases are uncommon outside of a few select populations. A 5-alpha-reductase defect may cause XX individuals to experience delayed menstruation and reduced hair growth.
DHT is essential for penile growth during puberty. DHT works with testosterone to increase size of male external genitalia. However, this does not mean that testosterone or DHT will make your penis larger. After puberty, adult men no longer have androgen receptors within their penile tissue.
It is still unclear what role DHT plays in male sexual function. Many of the data comes from indirect studies of 5-alpha reducer inhibitors, rather than direct studies of DHT levels. However, some studies have shown an increase of erectile dysfunction among men who take 5-alpha reductase inhibitors to lower their DHT levels. They also have been shown to reduce libido, sex drive, and sexual desire. DHT is believed to play an important role in male sexual desire.
DHT-lowering drugs can also affect male sexual function. However, this does not mean that DHT treatment will improve sexual function. Higher levels of DHT may not be always better. DHT levels can interact with other steroid levels, so increasing DHT can cause a decrease in other hormones like estrogen. DHT could have a negative impact on male sexual function.
DHT’s effects on male fertility are still not clear. DHT is produced by enzymes in the prostate, penis and scrotum. They are not found in the testes. DHT is not required for spermatogenesis.
Some data suggest that 5-alpha reductase inhibits may affect sperm production temporarily. In some studies, these drugs have been linked to decreased sperm count or reduced semen volume. It has also been associated lower sperm motility.
These effects are fortunately reversible if treatment is stopped. Other studies have not shown any changes in the sperm parameters after low-dose finasteride treatment. Therefore, further research is needed.