How Young Men in Their 20s and 30s Should Approach Hair Loss [Kim Jin-oh's Hair Loss Escape]

[Financial News] The first thing to assess when noticing hair shedding from the scalp is not the number of hairs shed but the pattern of shedding. Even if shedding temporarily increases, it is not classified as a pathological condition if hair thickness and the growth cycle remain within normal ranges. The criterion for determining whether hair loss is pathological is not the number of hairs shed, but a decrease in the diameter of newly growing hair and a shortening of its cycle.

Hair loss in younger people is broadly divided by its underlying mechanism into telogen effluvium and androgenetic alopecia. The two conditions differ completely in their causes, clinical presentation and prognosis.
Telogen effluvium is a condition in which the body reacts to environmental stressors. Major triggers include serious illness, surgery, high fever, extreme psychological stress, and protein, iron or zinc deficiencies caused by extreme weight loss over a short period. When these stressors occur, the body deprioritizes hair growth in its metabolism and prematurely shifts a substantial proportion of all hair follicles into the resting phase. Because it typically takes 2–3 months for hair in the resting phase to shed, hair loss is observed across the scalp 2–3 months after the triggering event. Once the underlying cause is addressed, telogen effluvium resolves and the normal hair cycle returns over roughly six months.
Traction alopecia, in which hair is pulled out by force, is also something that must be distinguished from other types of hair loss. If hairstyles that place sustained tension on the scalp and follicles, such as ponytails and dreadlocks, are maintained for a long time, follicles around the hairline can become inflamed, causing localized hair loss. Recovery is possible in the early stages if the pulling stops, but if the external force continues for years, the follicles are destroyed and permanent fibrosis develops.

By contrast, androgenetic alopecia is a condition that progresses irreversibly due to genetic predisposition and hormone metabolism. Testosterone secreted by the testes and adrenal glands is converted into dihydrotestosterone (DHT) by type II 5-alpha-reductase. The condition develops when DHT binds to androgen receptors in follicles in the frontal and crown areas. This binding disrupts the signaling system in follicle cells, shortening the hair growth phase and prolonging the resting phase.
As a result, with each cycle, normal terminal hair gradually regresses into vellus hair that is thinner in diameter and shorter in length. This is called follicular miniaturization. Androgenetic alopecia is limited to the M-shaped hairline and crown, without affecting the back or sides of the scalp, because the activity of 5-alpha-reductase and the density of androgen receptor expression in follicles in those areas are far higher than in the back of the scalp.
It is therefore necessary to use visual examination and magnification to distinguish whether localized miniaturization is making the hair at the front and crown thinner than the hair at the back of the scalp, or whether hair of a uniform thickness is shedding rapidly across the entire scalp. In the former case, improving lifestyle habits, cleansing the scalp and adjusting the diet cannot block the hormone-binding mechanism, so they will not stop the condition from progressing.

For confirmed androgenetic alopecia, the medical first-line treatment is medication for hair loss. Common medications include finasteride, dutasteride and minoxidil.
Oral finasteride and dutasteride competitively inhibit 5-alpha-reductase, reducing DHT levels in the blood and scalp tissue by approximately 60–70%. When DHT levels fall, signals that cause follicle atrophy are blocked, normalizing the hair cycle and slowing the condition's progression.
Minoxidil opens potassium channels and induces local vasodilation, increasing microcirculation around hair follicles. It also promotes the expression of growth factors within cells, extending the hair growth phase. Because finasteride and minoxidil act through independent biological pathways, using them together has a statistically significant synergistic effect in improving hair density and diameter.

One important fact to understand before starting treatment is that these medications have clear clinical limitations. First, finasteride and minoxidil are not regenerative treatments that create new follicles after atrophy is complete and the matrix cells have been entirely lost. They are conservative treatments that delay miniaturization in still-living follicles and help maintain the diameter of thinned vellus hairs. As a result, the response to medication drops sharply once a follicle has fully atrophied.
Second, the treatment effect lasts only while medication is continued. If medication is stopped or topical application is discontinued, the blocked DHT-binding pathway and blood-flow environment revert to their original genetic course. Within a few months, hair maintained by treatment regresses, and the condition progresses to the same level as in untreated patients.
Third, the possibility of side effects must be considered, including reduced sexual function when taking medication (a decrease in libido, erectile dysfunction, reduced ejaculate volume and other effects, in around 5–10% of cases), as well as localized contact dermatitis, itching and initial shedding when applying minoxidil.
Whether to treat androgenetic alopecia should be decided after objectively weighing these mechanisms and limitations. Whether to slow the rate of hair loss through ongoing medication management for life or to follow the natural course of genetic progression without medical intervention is the patient's choice. However, that decision should be made only after a clear differential diagnosis determines whether the biological process underway on the scalp is temporary telogen shedding or progressive miniaturization of follicles due to androgenetic alopecia.

/Director Kim Jin-oh of New Hair Plastic Surgery Clinic
[email protected] Kim Hyeon-seon Reporter