Many people may have heard of the name “minoxidil” when it comes to hair loss treatment. Clinical studies in Japan and abroad have scientifically demonstrated its hair growth effects, and it is widely used as a key component in AGA (androgenetic alopecia) therapy.
However, one of the most frequently asked questions from patients is, “How much does it cost?” In addition, doubts such as “Which is more effective, topical or oral?” and “Is there a difference between generic and brand-name products?” are common.
This article provides a detailed expert review of minoxidil’s price ranges, efficacy, potential side effects, and the importance of treatment continuity, offering valuable insights for those considering AGA treatment.

1. What is Minoxidil? — Mechanism of Action and Hair Growth Pathways

① Development of Minoxidil and Its Position as a Medication

Minoxidil was originally developed as an antihypertensive (blood pressure-lowering drug). Research began in the United States in the 1960s, where its potent vasodilatory effect was confirmed. Later, during administration to hypertensive patients, frequent occurrence of “generalized hair growth” as a side effect attracted attention to its potential as a hair treatment.
By the 1980s, topical formulations were approved, and Japan’s Ministry of Health, Labour and Welfare also authorized it as a “treatment for androgenetic alopecia.” Today, it is used worldwide as a first-line option in AGA treatment.

② Mechanism of Action in Detail

The hair growth effect of minoxidil is considered multifactorial, with several mechanisms working in combination:

• Improved scalp blood flow through vasodilation
  Minoxidil opens ATP-sensitive potassium channels, dilating capillaries. This increases scalp blood flow and enhances oxygen and nutrient delivery to hair follicles, creating a favorable environment for hair growth.
  
• Stimulation of dermal papilla and hair matrix cells
  Dermal papilla cells at the base of hair follicles are crucial regulators of hair growth. Minoxidil activates these cells, promoting the division and proliferation of hair matrix cells. As a result, thin, short vellus hairs can mature into thick, long terminal hairs.
  
• Regulation of the hair cycle (extended growth phase, shortened resting phase)
  Hair normally cycles through anagen (growth), catagen (regression), and telogen (resting). In AGA, the anagen phase shortens, leaving only fine hairs. Minoxidil normalizes this cycle, prolonging anagen and increasing the number of growing hairs.
  
• Promotion of VEGF (vascular endothelial growth factor) production
  Minoxidil acts on dermal papilla cells to increase VEGF, a factor that promotes new capillary formation. This strengthens the vascular network around follicles, further supporting hair growth.
  

③ Clinical Evidence of Hair Growth Effects

• Continuous use of 5% topical minoxidil for more than 6 months has shown improved hair growth in about 60–70% of patients.
  
• Fine hairs typically begin to appear within 3 months, with thicker, more visible hairs developing after 6 months or longer.
  
• However, once treatment is stopped, AGA progression resumes, and the condition can revert within a few months. Continuous use is essential.
  

④ Differences Between Topical and Oral Minoxidil

• Topical (approved in Japan)
  Acts directly on the scalp; side effects are mostly dermatological. Particularly effective for thinning at the crown.
  
• Oral (not approved in Japan)
  Reaches high blood concentrations and acts systemically, producing stronger effects. However, side effects such as palpitations, edema, and hypotension require caution.
  

2. Types of Minoxidil and Methods of Administration

① Topical Minoxidil

Currently, the most common formulation in Japan is topical minoxidil, applied directly to the scalp for local action.

• Concentration Differences
  
  • For men: 5% is the standard, shown effective in clinical trials to slow AGA progression and stimulate regrowth.
    
  • For women: 1–2% is recommended. Higher concentrations risk excessive body hair growth, so physician supervision is ideal.
    
• How to Use
  Apply twice daily (morning and evening) to a dry scalp, massaging gently for absorption. Avoid concurrent use with styling products for best results.
  
• Advantages
  
  • Readily available at drugstores or online
    
  • Relatively safe with fewer side effects
    
• Disadvantages
  
  • Requires consistent use for 3–6 months before noticeable results
    
  • Possible skin issues such as itching, dandruff, or dermatitis
    

② Oral Minoxidil

Oral formulations are considered more powerful than topical ones, acting systemically via the bloodstream. Often chosen when topical treatment alone is insufficient.

• Status in Japan
  Not approved domestically; prescribed only through private clinics as non-insured treatment.
  
• Efficacy Characteristics
  
  • Stronger hair growth effects than topical
    
  • May improve frontal and hairline thinning that topical therapy struggles to address
    
• Potential Side Effects
  
  • Cardiovascular issues such as palpitations, hypotension, and headaches
    
  • Edema and weight gain due to fluid retention
    
  • Hypertrichosis (excessive body hair) is also common
    
• Usage Precautions
  Requires medical supervision with regular monitoring of blood pressure and cardiac function. Not suitable for those with certain pre-existing conditions.
  

③ Comparison of Topical vs. Oral Minoxidil

④ Continuation and Assessing Effectiveness

• Time to Results
  
  • Topical: Fine hairs at 3–6 months, visible improvement at ~1 year
    
  • Oral: Faster results, but with higher risk of adverse effects
    
• Risk of Discontinuation
  Effects last only while in use. Stopping leads to resumed AGA progression within months. Success depends on long-term adherence.
  

3. Price Range of Minoxidil — Comparing Topical and Oral

① Price Range of Topical Minoxidil

The only officially approved form in Japan. Prices vary by concentration:

• Brand (e.g., Rogaine/Reup series)
  
  • ~¥7,000–8,000 per month (30-day supply)
    
  • High trust and reliability but costly
    
• Domestic generics
  
  • ~¥3,000–5,000 per month
    
  • Same active ingredient, different packaging/feel
    
• Imported generics (via personal import, e.g., Kirkland, Rogaine)
  
  • ~¥2,000–4,000 per month
    
  • Very cost-effective but quality and safety are patient’s responsibility
    

② Price Range of Oral Minoxidil

Not approved in Japan, available only through private treatment.

• Imported generics
  
  • ~¥3,000–6,000 per month
    
  • Cost-effective but lacks safety monitoring
    
• Domestic private clinics
  
  • ~¥5,000–10,000 per month (including consultation and tests)
    
  • Safer, with physician oversight and health checks included
    

③ Annual Cost Comparison

④ Importance of Long-Term Costs

AGA therapy requires long-term commitment. Minoxidil’s effects disappear within months of discontinuation, so affordability is key.

• Brand → Reliable but expensive
  
• Generic → Same effect at lower cost
  

Oral → Strong results, but balance of risk and price must be considered

4. Effectiveness and Side Effects — Why Price Shouldn’t Be the Only Factor

① Effectiveness of Minoxidil

Minoxidil is the only scientifically proven topical hair regrowth agent.

• Evidence
  
  • 5% topical: 60–70% of patients see hair regrowth within 6 months
    
  • Oral: 70–90% improvement, but higher risk
    
• Effective areas
  
  • Topical: crown thinning
    
  • Oral: crown + frontal/hairline
    

② Side Effect Risks

• Topical (5–10% incidence)
  
  • Itching, dandruff, redness, dermatitis
    
• Oral (10–20% incidence, some higher)
  
  • Palpitations, tachycardia, hypotension, headaches
    
  • Edema, weight gain
    
  • Hypertrichosis (30–40%)
    
  • Rare but serious: arrhythmia, heart failure in at-risk patients
    

③ Comparison of Effectiveness vs. Side Effects

④ Other Key Considerations Beyond Price

• Safety
  Cheap imported products may be counterfeit or lack medical support if adverse effects occur.
  
• Compatibility with personal health
  Sensitive skin → topical may irritate
  Heart/blood pressure issues → oral should be avoided
  
• Sustainability
  Long-term affordability is essential, as stopping treatment leads to relapse.
  

5. Tips to Reduce Costs and Ensure Treatment Continuity

• Choose generics → Same ingredient, lower cost
  
• Use subscription or telemedicine services → Discounts for bulk or remote consultations
  
• Improve lifestyle habits → Adequate sleep, balanced diet, and stress control help slow AGA progression
  

Conclusion

Minoxidil remains the core component of AGA treatment, with both topical and oral formulations offering benefits. However, prices vary greatly depending on whether it’s brand or generic, topical or oral.

• Topical: ~¥2,000–8,000 per month
  
• Oral: ~¥3,000–10,000 per month
  

When choosing treatment, balance price, effectiveness, and side effect risk. Affordable, sustainable therapy under physician guidance is the first step to safe and effective hair regrowth.

記事の監修者

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岡 博史 先生

CAPラボディレクター

慶應義塾大学 医学部 卒業

医学博士

医師