Dr. Arslan Musbeh, MD
Hair Restoration Surgeon
Founder – Hairmedico
Lecturer, Claude Bernard University Lyon 1
17+ Years of Experience in FUE, Sapphire FUE, and DHI Hair Transplantation

Abstract

Clascoterone (Breezula®) is a topical androgen receptor antagonist developed for the management of androgenetic alopecia (AGA). As patient demand shifts toward non-systemic hair loss therapies, clascoterone has emerged as a promising option for localized androgen modulation. However, its clinical role is frequently misunderstood and overstated.

This clinical white paper provides a comprehensive evaluation of clascoterone’s pharmacological mechanism, clinical limitations, evidence base, patient selection criteria, and integration into surgical and non-surgical hair restoration strategies, including post–hair transplant use.

Core conclusion: Clascoterone does not induce new hair follicle formation. Its therapeutic value lies in slowing disease progression and preserving existing hair follicles, particularly as part of long-term maintenance protocols.

1. Introduction: Androgenetic Alopecia as a Progressive Disease

Androgenetic alopecia is the most common form of hair loss worldwide, affecting up to 80% of men and 50% of women during their lifetime. Although medically benign, AGA has a significant psychological and social impact, driving sustained demand for effective and safe treatments.

While oral 5α-reductase inhibitors remain effective, concerns regarding systemic exposure and side effects have accelerated interest in topical, localized anti-androgen therapies, positioning clascoterone at the forefront of current research.

2. Pathophysiology of Androgenetic Alopecia

AGA is driven by genetically determined follicular sensitivity to androgens, primarily dihydrotestosterone (DHT).

Key Pathophysiological Processes

• Conversion of testosterone to DHT via 5α-reductase
• Binding of DHT to androgen receptors in dermal papilla cells
• Progressive follicular miniaturization
• Shortening of the anagen (growth) phase
• Transition from terminal to vellus hair
• Eventual follicular dormancy

Once follicular stem cell niches are irreversibly damaged, pharmacologic regeneration is not possible.

3. Therapeutic Target: Androgen Receptor Blockade

Unlike therapies that reduce systemic androgen levels, clascoterone targets the final common pathway of androgen action by competitively blocking androgen receptors at the follicular level.

This strategy aims to:

• Reduce local androgen signaling
• Slow follicular miniaturization
• Preserve follicular integrity
• Avoid systemic hormonal suppression

4. Clascoterone (Breezula®): Molecular and Pharmacological Profile

Clascoterone (CB-03-01) is a non-steroidal anti-androgen formulated for topical dermatologic use.

Pharmacodynamics

Competitive inhibition of androgen receptors

Localized scalp activity

Rapid metabolism into inactive compounds

Minimal systemic hormonal impact

Pharmacokinetics

Low systemic absorption

No clinically meaningful serum androgen suppression

Favorable profile for long-term use

5. Development History and Concentration Differentiation

5.1 Clascoterone 1% (Winlevi®)

FDA-approved for acne vulgaris

Demonstrates validated local anti-androgen activity

Hair loss use remains off-label

5.2 Clascoterone 7.5% (Breezula®)

Developed specifically for androgenetic alopecia

Investigated in Phase II and III clinical trials

Optimized for scalp penetration and follicular receptor inhibition

6. Evidence Review: What Clinical Data Demonstrates

Available clinical data indicates:

• Modest increases in target area hair count
• Slower progression compared to placebo
• Improved hair cycle stability
• Critically, no clinical trial demonstrates new hair follicle formation. Observed improvements reflect preservation of existing follicles and delayed miniaturization, not regeneration.

7. Clinical Limitations and Common Misconceptions

Biological Reality

Hair follicles are embryologically determined structures. Once destroyed, they cannot be recreated pharmacologically.

Incorrect Classifications

❌ Hair regrowth drug

❌ Replacement for finasteride in all cases

❌ Alternative to hair transplantation

Correct Clinical Positioning

✔ Disease-modifying

✔ Progression-slowing

✔ Maintenance-focused therapy

8. Patient Selection Criteria

Optimal Candidates

Early to moderate AGA

Diffuse thinning with residual follicles

Patients avoiding systemic anti-androgens

Post–hair transplant patients for native hair preservation

Suboptimal Candidates

Advanced baldness with slick scalp

Patients expecting density restoration without surgery

9. Integration into Hair Transplant Surgery

Hair transplantation remains the only definitive method for restoring hair in areas of permanent follicular loss.

Preoperative Role

Stabilizes ongoing hair loss

Protects native hair adjacent to recipient zones

10. Post–Hair Transplant Use of Clascoterone: Clinical Rationale

From a surgical and clinical perspective, we consider clascoterone to be potentially effective in the post–hair transplant period, particularly for preserving native, non-transplanted hair.

Hair transplantation restores follicles in bald areas but does not halt the underlying androgenetic process affecting remaining hair. Progressive miniaturization of native follicles may continue if androgen activity is not managed.

Postoperative Clinical Rationale

Based on its mechanism of action, postoperative use of clascoterone may contribute to:

• Reduced androgen receptor activation in native follicles
• Slower miniaturization of non-transplanted hair
• Improved long-term balance between transplanted and existing hair
• Better maintenance of overall scalp density harmony

It is important to note that clascoterone does not affect the survival or growth of transplanted grafts themselves. Its value lies in protecting surrounding native hair, which is essential for long-term aesthetic stability.

Clinical Positioning After Surgery

In postoperative protocols, clascoterone should be positioned as:

A supportive maintenance therapy

Part of long-term medical management of AGA

A strategy to reduce future contrast between transplanted and non-transplanted zones

This role is preventive, not regenerative, and complementary to surgery.

11. Combination Therapy Framework

Optimal outcomes are achieved through a multimodal approach, which may include:

• Topical or oral minoxidil
• PRP therapy
• Medical-grade scalp care
• Nutritional and lifestyle optimization
• Such layered strategies reflect best practice in modern hair restoration.

12. Safety, Compliance, and Long-Term Use

Clascoterone’s localized action offers:

• High patient compliance
• Low discontinuation rates
• Minimal systemic side effects
• This makes it particularly suitable for long-term disease management.

13. Developer Perspective: Cosmo Pharmaceuticals

Breezula® is developed by Cosmo Pharmaceuticals N.V., a research-driven dermatology-focused pharmaceutical company. The product represents a strategic extension of Cosmo’s clascoterone platform, following the FDA approval of clascoterone 1% (Winlevi®).

Importantly, Cosmo positions Breezula® as a maintenance and disease-modifying therapy, not a follicular regeneration drug—fully aligned with current scientific consensus.

14. Ethical Positioning and Clinical Responsibility

Accurate positioning is essential to maintain patient trust. Overstating efficacy leads to unrealistic expectations and dissatisfaction.

Clascoterone must be communicated as:

• Supportive
• Preventive
• Maintenance-focused
• Not curative.

Conclusion

Clascoterone (Breezula®) represents a meaningful advancement in localized androgen modulation for androgenetic alopecia. While it does not regenerate hair follicles, it plays a valuable role in slowing disease progression, preserving existing hair, and supporting long-term outcomes, particularly after hair transplantation.

Used appropriately, it enhances both medical and surgical hair restoration strategies.

Effective Products Against Hair Loss: A Medical Perspective

In modern hair loss management, treating symptoms alone is never sufficient. Long-term stabilization and preservation of hair density require products that directly target the biological mechanisms responsible for follicular miniaturization.

Understanding how effective hair loss products work—beyond cosmetic benefits—is essential when evaluating both pharmaceutical agents such as clascoterone and supportive medical-grade formulations.

For a comprehensive, evidence-based explanation of what truly defines effective hair loss products, this in-depth medical article provides a clear clinical framework:

Effective Products Against Hair Loss: A Medical and Evidence-Based Approach

This resource explains in detail:

Why DHT remains the central driver of androgenetic hair loss

How Saw Palmetto and similar agents contribute to long-term follicular protection

Why cosmetic-only products fail to deliver sustainable results

The importance of combining topical and systemic strategies as a unified treatment system

In the context of clascoterone (Breezula), which acts as a topical androgen receptor antagonist, understanding these foundational principles allows clinicians and patients to place pharmacological treatments within a broader, medically structured hair loss strategy rather than viewing them as standalone solutions.

A scientifically grounded approach—supported by both targeted pharmacology and long-term follicular support—remains the cornerstone of successful hair loss management.

Clascoterone (Breezula®) vs Hair Transplant – Clinical Comparison Table

Clinical Summary 

Hair transplantation restores what has been lost; clascoterone slows further loss. The most stable, long-term outcomes are achieved when both are used together.

References (Condensed)

Dermatology Times; Cosmo Pharmaceuticals Pipeline; American Hair Loss Association; Perfect Hair Health; The Derm Digest.

This clinical white paper has been approved by Dr. Arslan Musbeh.