In this blog post, we will look at why hair loss is difficult to cure due to various causes, and in particular, how hereditary hair loss is treated.
Despite the steady development of medical technology over thousands of years, hair loss is still incurable. There are various factors that cause hair loss. These can be divided into genetic and stress-related factors, and in addition to these, diabetes, smoking, metabolic changes caused by drastic dieting, and incorrect habits such as exposing oneself to too much hot air or brushing one’s hair too hard can also cause hair loss. As the causes are diverse, there are various types of hair loss and treatment methods, but currently, there is almost no hair loss that can be completely cured. However, in the case of hereditary hair loss, which has been well studied in terms of its mechanism, it can be completely cured through drug treatment in the early and mid-stages. Therefore, we will focus on hereditary hair loss, which can be completely cured with modern medical technology.
First of all, it is necessary to recognize that hair loss is not a simple symptom but a disease. A disease is a condition in which the physical functions of an organism become abnormal. In a broader sense, stress or genetic factors can also be considered diseases. In this case, the boundary between a phenomenon caused by the expression of genes and a symptom or disease can be problematic, and social factors play a major role in this case. If society sees these symptoms as a disease, it is a disease, and if not, it is simply a phenomenon caused by gene expression. It is not clear how it was perceived in the old days, but at least in modern society, hair loss is treated as a disease that requires medication and causes stress to patients. In fact, the National Health Insurance Service of Korea recognizes hair loss as a disease and includes it in the list of medical examination status surveys.
Hereditary hair loss is often referred to as hereditary androgenic alopecia. Androgen refers to all substances that exhibit the action of male hormones. However, when it comes to hair loss, testosterone and dihydrotestosterone, or DHT for short, are the two main substances that are usually discussed. Let’s start by explaining how male hormones, which are known to be involved in the development of secondary sexual characteristics, cause hair loss.
Testosterone, a male hormone that is mainly produced in the testes of men and the ovaries and adrenal cortex of women, travels to the hair follicles. Before this testosterone reaches the hair follicle, about 5% of the total amount is converted to DHT by an enzyme called 5α-reductase. In the hair follicle, testosterone and DHT coexist. The problem is that DHT binds to androgen receptors located in the hair follicle many times more strongly than testosterone. When DHT binds to the receptor, instead of producing hair-producing factors, it produces cell-killing factors such as DKK-1 and TGF-beta, which destroy the proteins of the cells themselves and surrounding cells and accelerate the hair’s degenerative phase. This causes the hair to become thinner and weaker, and the hair falls out easily, which is commonly referred to as hair loss. In short, DHT binds to receptors instead of testosterone, which causes hair to become thinner. In other words, if our body has normal levels of the enzyme that reduces testosterone, DHT will be produced steadily and hair loss will progress.
The important point here is that the rate at which hair loss progresses varies from person to person depending on their unique genes. Hereditary hair loss patients have a shorter time for their hair to weaken and thin because they have factors that negatively affect hair formation from birth. Looking at the mechanism, the factors that control hair are testosterone, 5-alpha-reductase, androgen receptors, hair growth factors, and cell suicide factors. In other words, people with the hair loss gene have more 5-alpha-reductase genes than others, more androgen receptors that can bind to DHT than others, and genes that produce relatively more cell suicide factors than hair growth factors. Hair loss caused by the inheritance of these genes is called hereditary hair loss (male-pattern hair loss).
If so, to prevent hereditary hair loss, one can consider reducing the amount of testosterone, reducing the amount of 5-alpha-reductase, or inhibiting androgen receptor binding. However, it was not easy. There are 66 types of hair loss drugs for men currently being distributed and produced in Korea, but only two officially approved drug treatments for hereditary hair loss have been approved by the FDA. One is a minoxidil-based treatment, and the other is Propecia.
First, the minoxidil-based treatment was originally a drug developed by a pharmaceutical company called Upjohn in the 1950s to treat stomach ulcers. However, it was not effective for stomach ulcers, and instead it excellently dilated blood vessels, receiving FDA approval in 1979 under the name “Loniten.” However, patients taking this drug developed a side effect called hirsutism, which was used to treat hair loss and was approved by the FDA as a hair loss treatment in 1988. It is not exactly known why minoxidil causes hirsutism, but it is believed that increased blood flow to the hair follicles increases the nutrients that go to the hair, allowing it to grow more. This medicine comes in a form that is applied directly to the head and in pill form. It is said that the thinning hair will grow back if it is used consistently for at least six months. However, because it acts to dilate blood vessels, it cannot be taken by people with low blood pressure, and there may be side effects such as heart palpitations or persistent nervousness.
Second, Propecia (finasteride) was originally developed as a treatment for benign prostatic hyperplasia, but it has been found to be effective in treating hair loss and is therefore used as a hair loss drug. The mechanism of Propecia is relatively well understood. This drug can slow down hair loss by reducing the amount of DHT by inhibiting the amount of 5-alpha-reductase. Propecia was used as a treatment for benign prostatic hyperplasia, similar to minoxidil, and was approved by the FDA for androgenetic alopecia in 1997 after the mechanism of hereditary hair loss was discovered. Patients with 5-alpha-reductase deficiency provided a major clue to the invention of Propecia.
In a small town in the Dominican Republic, there were many newborns with a deficiency of 5-alpha-reductase due to incest. Children without DHT do not develop primary sexual characteristics, and only when they develop secondary sexual characteristics do they experience an explosive increase in testosterone, resulting in masculinization of the genitals. Focusing on this point, efforts to find a drug that reduces 5-alpha-reductase began. Later, it was discovered that 5-alpha-reductase plays an important role in the mechanism of hereditary hair loss, and a hair loss treatment was developed based on this. However, since it was originally developed as a treatment for benign prostatic hyperplasia, it may have side effects such as decreased sex drive due to increased female hormones. Also, since the possibility of male birth defects increases in pregnant women, this drug should not be taken by pregnant women.
In addition to the above-mentioned drugs, there are various treatments such as anti-androgen drugs such as spironolactone that prevent androgen receptor binding, drugs of the dutasteride class that inhibit both type 1 and type 5 5-alpha-reductase, and physical methods such as hair transplantation, but Due to a lack of information on the extent of side effects and the exact efficacy of the drug, it is only approved or used in some regions. However, we must not forget that early detection and consistent treatment are the most effective hair loss treatments of all.
