The main driver of AGA is the hormone DHT (dihydrotestosterone). Testosterone is converted into DHT by the 5-alpha reductase enzyme, and DHT then binds to androgen receptors (AR) in the dermal papilla, disrupting the hair cycle and shortening the growth (anagen) phase. Genetics also play a strong role, and AGA can be inherited from either the father's or the mother's side.

How soon do AGA medications start to work?

Timelines vary by drug. Finasteride often reduces shedding within 3 to 6 months of starting, with visible regrowth typically confirmed between 6 months and 1 year. Minoxidil tends to produce vellus hair growth from around 3 months, with substantial regrowth expected between 6 months and 1 year.

AGA Self-Check Guide for Men: Hair Loss Stages, Patterns & When to Start Treatment

AGA self-check: physician guide to hair loss progression

“My hairline seems to be receding lately.” “The scalp at my crown is starting to show through.” If those thoughts sound familiar, they may be early signs of AGA (androgenetic alopecia / male pattern baldness).
AGA is a progressive condition, and the longer it is left untreated, the harder it becomes to manage. Many patients delay consultation by telling themselves “it is not that bad yet” or “it is just my age.”

This article walks through, under physician supervision, an AGA self-check list, progression classification, the underlying causes, and the right time to start treatment. An eight-item checklist is included so you can answer the question “Do I have AGA?” Start with the self-check.

Table of contents

What is AGA? Male pattern baldness basics
8-item AGA self-check list
AGA progression: the Hamilton-Norwood scale
Causes of AGA: DHT, genetics, and lifestyle
Treatment options: OTC products vs. medical care
The treatment journey: from first visit to start
AGA treatment costs at a glance
Frequently asked questions (FAQ)
Summary

What is AGA? Male pattern baldness basics

Male pattern baldness / AGA basics

AGA (Androgenetic Alopecia) is a progressive form of hair loss driven by male hormones. In Japanese it is called “male pattern baldness,” and approximately 30% of Japanese men develop AGA in their thirties and around 40% in their forties (data from the Japanese Dermatological Association).

A hallmark of AGA is the distinctive pattern of thinning at the front (hairline) and crown. This happens because hair follicles in those areas carry abundant androgen receptors that respond to DHT, a hormone derived from male androgens, and the resulting signal disrupts the hair cycle.
Follicles on the sides and back of the head are far less sensitive, so the contrast in pattern is an important diagnostic clue for AGA.

Because AGA is a progressive disease, untreated thinning gradually spreads. However, starting appropriate treatment early has been shown clinically to slow progression and promote regrowth.

Note: AGA differs from other forms of hair loss. Alopecia areata (autoimmune) and diffuse alopecia (driven by stress or nutritional deficiency) require different approaches. “Patterned thinning at the frontal and crown areas” is a typical AGA sign; other patterns should be assessed for a differential diagnosis at a dermatology or hair clinic.

AGA prevalence by age

Age group	Prevalence (approx.)	Characteristics
20s	approx. 10-15%	Early onset; treatment is most effective.
30s	approx. 30%	Hairline recession and crown thinning become apparent.
40s	approx. 40%	Progression often accelerates; early intervention matters.
50s and beyond	approx. 50%+	Some stabilisation as testosterone declines; the goal shifts to maintenance.

8-item AGA self-check list

AGA self-check: assessing hair loss

Tick any items below that apply to you. If three or more apply, AGA is likely and a clinic visit for diagnosis is recommended.

✅ AGA self-check list

□ My frontal hairline is receding (M-shape / general recession)
□ My scalp shows through at the crown
□ I am shedding more hair than before (rough guide: more than 100 hairs per day)
□ My hair has become finer and lost body and resilience
□ I am seeing more short, vellus-like hairs
□ My father or grandfather (paternal or maternal) experiences thinning
□ I started noticing thinning in my teens or twenties
□ My forehead looks larger and the scalp veins are visible

How to interpret your score:
– 0-2 items: AGA is unlikely, but early AGA can be hard to spot, so keep an eye on changes.
– 3-4 items: AGA is possible; consider a clinic visit for diagnosis.
– 5 or more items: AGA is likely; book a specialist consultation as soon as possible.

How does this differ from “seasonal shedding”?

Autumn (September to November) is a transitional season when shedding tends to increase. Seasonal shedding is uniformly distributed and usually settles within two or three months. AGA, by contrast, concentrates at the frontal and crown areas and does not recover on its own. If you sense increased shedding, check the pattern (where it is coming from) carefully.

AGA progression: the seven-stage Hamilton-Norwood scale

AGA progression and Hamilton-Norwood scale

The international standard used to assess AGA progression is the Hamilton-Norwood scale (Type I to Type VII). Identify the type that most resembles your current state.

Type	State	Expected treatment response
Type I	Normal hairline; no thinning.	Preventive treatment is possible
Type II	Slight hairline recession (early M-shape)	Excellent regrowth and progression-control
Type III	Clear hairline recession with early crown thinning	Optimal stage to start treatment
Type IV	Distinct frontal and crown thinning, still separated	Good progression control with some regrowth
Type V	Frontal and crown thinning beginning to merge	Progression control is the primary aim
Type VI	Wide-area thinning across the frontal and crown	Maintenance and slowing of progression
Type VII	Most advanced stage; only the sides and back remain	Drug therapy alone offers limited benefit

Key point: The earlier the stage (Type II to III), the higher the treatment effectiveness, with strong outcomes for both regrowth and density. Even from Type IV onward, meaningful slowing of progression is realistic. It is never “too late” – the most important step is to consult a clinic and understand your current state.

AGA patterns common among Japanese men

Japanese patients commonly present with a combination of “M-shape (frontal recession)” and “O-shape (crown thinning)” patterns. Crown progression is more frequent than in Western populations, and because the crown is hard to monitor yourself, comparing photographs taken from the back of the head over time is an effective way to detect early changes.

Causes of AGA: DHT, genetics, and lifestyle

AGA: male hormones, DHT, and genetic factors

Cause 1: DHT (dihydrotestosterone)

The leading cause of AGA is the hormone DHT (dihydrotestosterone). Testosterone (a male hormone) is converted into DHT by 5-alpha reductase (type II); DHT then binds to androgen receptors in the dermal papilla and shortens the growth (anagen) phase of the hair cycle.
With a shortened growth phase, hairs cannot mature into thick, long strands and are shed while still fine and immature. Over time the follicles themselves shrink and disappear.

Cause 2: Genetic factors

AGA has a strong hereditary component. Risk increases when a family member on either the father side or mother side has AGA. 5-alpha reductase activity and androgen receptor sensitivity are heritable, but the misconception that “it is genetic, so nothing can be done” is wrong: medication can suppress DHT production.

Cause 3: Lifestyle and external factors (accelerators)

The factors below are not direct causes of AGA, but they are known to accelerate thinning and shedding.

Sleep loss and overwork: reduced overnight growth-hormone secretion impairs follicle repair
Chronic stress: vasoconstriction lowers blood flow to the scalp
Imbalanced nutrition: shortages of protein, zinc, and biotin starve hair-forming raw materials
Smoking: impaired circulation blocks nutrient supply to follicles
UV exposure and scalp damage: oxidative stress harms the follicles

Lifestyle changes alone cannot stop AGA, but combining them with medication can produce a meaningful synergistic effect. Japan’s Ministry of Health, Labour and Welfare also recommends combining medical treatment with lifestyle improvement when addressing hair loss.

If three or more items applied to your self-check

The earlier you treat hair loss, the better the outcome.
Start with a free consultation to understand your current state.

Book a free consultation

Start today, all from your smartphone | Online consultations from 6,900 JPY/month

Treatment options: OTC products vs. medical care

AGA approaches mostly fall into two camps: “over-the-counter hair tonics or shampoos” and “prescription medications from a medical institution.” There are major differences in efficacy, cost, and safety, so it is important to choose having understood the trade-offs.

Comparison	OTC hair tonics	Prescription medication
Evidence of efficacy	Limited clinical evidence	Strong clinical evidence
Main ingredients	Swertia, glycine, vitamins, etc.	Finasteride, minoxidil, dutasteride, etc.
Direct action on AGA	Does not suppress DHT production	Suppresses DHT and activates follicles
Monthly cost	Approx. 3,000-10,000 JPY	From 6,900 JPY (our online plan)
Physician support	None	Regular follow-up and side-effect management

Note: OTC topical minoxidil products (such as Riup) are available in pharmacies, but their concentration is low (1-5%) and effectiveness is limited compared with the higher-strength topical (5-15%) or oral minoxidil prescribed at clinics. Crucially, finasteride and dutasteride, which suppress AGA root cause (DHT), can only be obtained at a medical institution.

The treatment journey: from first visit to start

AGA treatment: clinic visit flow

For anyone who feels “the clinic is intimidating” or “I do not know what to do first,” here are the four steps from booking to active treatment. We also offer online consultations, so you can begin treatment today using only your smartphone.

STEP 1

Book a free consultation

Book online or by phone. Online consultations remove the need to visit in person. Jot down any concerns or questions in advance for a smoother session.

STEP 2

Physician scalp and hair assessment

Your scalp condition, thinning pattern, and progression are reviewed. Blood and scalp testing can pinpoint underlying drivers; online consultations rely on photographs and detailed questionnaires.

STEP 3

Treatment plan and prescription explanation

Medications (finasteride, minoxidil, etc.) and pricing plans are tailored to your stage and preferences, with full explanations of side effects and precautions.

STEP 4

Start treatment with three-month follow-ups

Begin the prescribed medication. Effectiveness is reviewed every three months and the regimen is fine-tuned. Visible regrowth is typically experienced between 6 and 12 months.

AGA treatment costs at a glance

AGA treatment is delivered through self-pay (non-insurance) care, so costs vary by clinic and prescription. The following figures are typical monthly ranges.

Medication	Action	Monthly cost
Finasteride (oral)	Inhibits 5-alpha reductase to suppress DHT production	3,000-8,000 JPY
Dutasteride (oral)	Stronger DHT suppression than finasteride	4,000-10,000 JPY
Minoxidil (topical)	Vasodilation increases follicular blood flow and promotes regrowth	3,000-8,000 JPY
Minoxidil (oral)	Stronger regrowth effect than topical	3,000-12,000 JPY
Combination therapy (recommended)	Finasteride + minoxidil and similar combinations	From 6,900 JPY (our online plan)

Note: AGA treatment is symptomatic, so costs continue as long as treatment continues. Even so, starting early to slow progression usually reduces total long-term spend. Late-stage cases tend to require stronger drugs at higher doses, so overall costs can rise.

Frequently asked questions (FAQ)

Q. How do I perform an AGA self-check?

A. Look for receding hairline at the front and temples, reduced volume at the crown, increased shedding (more than 100 hairs per day as a guide), thinning hair shafts and an increase in short hairs, and any family history. If three or more of the eight items in this article checklist apply, AGA is likely and an early consultation is recommended.

Q. Can AGA be treated without medical help?

A. Lifestyle changes alone rarely halt AGA. Because the root driver is the hormone DHT, and only finasteride and dutasteride (prescription only) can suppress it, OTC hair tonics that lack DHT-suppressing action have limited fundamental effect.

Q. How is AGA progression classified?

A. The international Hamilton-Norwood scale defines seven stages (Type I to VII). Type I is normal; Type II to III shows hairline recession (a great window for treatment); Type IV to V brings frontal and crown thinning; and Type VI to VII represents extensive loss. Earlier intervention (before Type III) tends to deliver stronger results.

Q. At what age does AGA start?

A. AGA can begin in the late teens. Among Japanese men, around 30% develop AGA in their thirties and 40% in their forties. Regardless of age, the moment you first notice thinning is the best time to seek consultation; earlier treatment tends to deliver stronger regrowth and density results.

Q. What causes AGA?

A. The main driver is the hormone DHT (dihydrotestosterone). Testosterone is converted into DHT by 5-alpha reductase, and DHT then binds to androgen receptors in the dermal papilla and shortens the growth phase of the hair cycle. Genetics also play a major role and can be inherited from either parent. Stress, sleep loss, and smoking are accelerators.

Q. How much do AGA medications cost?

A. Finasteride (oral) is typically 3,000-8,000 JPY per month, dutasteride 4,000-10,000 JPY, and minoxidil 3,000-12,000 JPY. Our clinic offers a physician-supervised online plan from 6,900 JPY per month for effective treatment.

Q. How soon do AGA treatments start to work?

A. Finasteride often reduces shedding within 3 to 6 months, with regrowth confirmed between 6 months and 1 year. Minoxidil tends to grow vellus hair from around 3 months, with substantial regrowth between 6 and 12 months. Sticking with treatment for at least 12 months is important.

Q. When should I start AGA treatment?

A. The moment you start to feel concerned about hair loss is the right time. AGA is symptomatic, so treatment is ongoing, but earlier starts deliver stronger regrowth and density gains and make progression easier to halt. While you tell yourself “it is not that bad yet,” the loss continues, so book a consultation as soon as a concern appears.

Summary

AGA is a progressive form of hair loss driven by DHT (a male hormone derivative); about 30-40% of Japanese men in their thirties and forties develop it.
If three or more of the eight self-check items apply, book a consultation early.
On the Hamilton-Norwood scale, Type II-III is the optimal window to start treatment.
OTC hair tonics cannot suppress DHT; finasteride and dutasteride are prescription-only.
Costs start from 6,900 JPY per month with our online consultation plan.
Earlier treatment delivers stronger regrowth and density, and reduces long-term spend.

Concerned about thinning? Start with a free consultation.

Online consultations let you start today using only your smartphone.
A physician will tailor a plan to your individual condition.

Book a free consultation now

Online consultations from 6,900 JPY/month | First consultation free

Related columns

Supervised by: Men’s Care Clinic physicians.
Specialists at this Japanese Ministry of Health, Labour and Welfare-licensed medical institution covering AGA, ED, STD care, medical weight management, and other men health services.
*This article is provided for educational purposes only and is not a substitute for diagnosis or treatment. If you are concerned about symptoms, please consult a physician.

Medically reviewed by

Masashi MoritaPhysician

MD, Showa University School of Medicine · PhD (Medicine), Showa University
Board Certified Urologist — The Japanese Urological Association
Board Certified Endocrinologist — The Japan Endocrine Society

This article has been reviewed by a doctor for medical accuracy. Individual symptoms are assessed by a doctor at consultation.