What is AGA (androgenetic alopecia)? How it progresses and how to choose the right treatment

What is AGA?

AGA (Androgenetic Alopecia) is a type of hair loss that progresses due to the involvement of male hormones and genetic factors. It often begins with a receding hairline and thinning at the crown, and if left untreated, it gradually worsens. Unlike the natural changes associated with aging, AGA is characterized by the ability to halt its progression or improve the condition by addressing the causative substances.

How AGA Progresses

Testosterone (male hormone) in the body is converted into a more active substance called DHT (dihydrotestosterone) by the action of an enzyme called 5α-reductase. When DHT binds to receptors (androgen receptors) in the hair follicles, the growth phase of the hair is shortened, leading to "miniaturization" where hair falls out before it can fully grow. It is believed that genetic factors play a significant role in how easily this 5α-reductase enzyme works and how sensitive individuals are to DHT.

Patterns of Progression

There are individual differences in progression patterns, such as a receding hairline, thinning from the crown, or both simultaneously. The Hamilton-Norwood scale, an international classification system for the extent of hair loss, is often used to categorize progression from mild to severe in stages.

Treatment: Oral Medications

The primary treatment for AGA is oral administration of 5α-reductase inhibitors (finasteride and dutasteride), which suppress the production of DHT.

Differences Between Finasteride and Dutasteride

There are two types of 5α-reductase, type I and type II. Finasteride inhibits only type II, whereas dutasteride inhibits both types I and II. Therefore, dutasteride is considered to have a higher DHT inhibitory effect and is also chosen as an alternative when finasteride has not been sufficiently effective. However, because higher efficacy may also lead to individual differences in side effects, many people still start with finasteride.

Side Effects of Oral Medications

• Decreased libido and impact on erectile function (not common, but consult a doctor if concerned)

• Impact on liver function (rare)

• Breast tenderness and pain (rare)

• Pregnant women or women who wish to become pregnant must also avoid contact with the medication (due to absorption through the skin)

Treatment: Topical Medications (Minoxidil)

Minoxidil is an ingredient that promotes hair growth through a mechanism different from oral medications (finasteride and dutasteride). It was originally developed as a vasodilator and is believed to improve blood flow to the scalp and extend the hair growth phase (the detailed mechanism of hair growth is not fully understood).

Differences in the Roles of Oral Medications and Minoxidil

Since finasteride/dutasteride, which "stop hair loss," and minoxidil, which "promotes hair growth," act through entirely different mechanisms, using both in combination is believed to lead to more effective AGA treatment.

Side Effects of Minoxidil

• Scalp itching and rash (for topical use)

• Palpitations and swelling (can be reported, especially with the oral type)

• Hypertrichosis (hair may grow more easily on areas other than the application site, such as the face)

About Female AGA (FAGA)

Female pattern hair loss (FAGA: Female Androgenetic Alopecia) has a different mechanism than male AGA, and often presents as diffuse thinning across the entire scalp. Finasteride and dutasteride cannot be used by pregnant women or women who wish to become pregnant, so topical minoxidil is the primary treatment for female hair loss.

Online Treatment Process

• ① Provisional Payment・Pre-consultation Questionnaire: Please enter your progression level, areas of concern, etc.

• ② Online Consultation: A doctor will confirm suitability via video call and propose a treatment plan.

• ③ Same-day shipping available at the earliest.

• ④ Regular consultations to monitor progress of effects and side effects.