Stages of Hair Growth: A Comprehensive Guide Through ASAHRS Lens

Understanding the stages of hair growth is the cornerstone of modern hair restoration, aesthetic medicine, and long-term patient outcomes. For physicians and medical professionals seeking mastery in this field, clinical knowledge alone is no longer enough. Today’s gold standard integrates biology, genetics, technology, and ethics—an approach championed by the American Society of Aesthetic & Hair Restoration Surgeons (ASAHRS) through its globally recognized fellowship programs.

Stages of Hair Growth

This article explores the stages of hair growth in detail and connects them directly to how the ASAHRS Fellowship trains physicians to diagnose, treat, and personalize hair restoration using advanced surgical, non-surgical, and genomic techniques.

Understanding the Stages of Hair Growth

Human hair growth follows a highly regulated biological cycle. Successful hair restoration—whether surgical or non-surgical—depends on understanding and respecting these stages.

1. Anagen Phase (Growth Phase)

The anagen phase is the active growth stage of the hair follicle.

• Lasts 2–7 years

• Around 85–90% of scalp hair is in this phase at any time

• Hair follicles are metabolically active and responsive to treatment

• Ideal phase for:

  • FUE hair transplantation

  • Growth factor therapy

  • Peptide and genomic-guided interventions

ASAHRS fellowship training emphasizes identifying follicles in optimal anagen activity to maximize graft survival and density.

2. Catagen Phase (Transition Phase)

The catagen phase is a short transitional stage.

• Lasts 2–3 weeks

• Hair growth stops

• Follicle detaches from blood supply

• Hair shaft prepares for shedding

Through ASAHRS training, physicians learn how hormonal imbalance, inflammation, and genetics can prematurely push follicles into catagen—an early sign of progressive alopecia.

3. Telogen Phase (Resting Phase)

The telogen phase is the resting stage.

• Lasts 3–4 months

• Around 10–15% of hairs are in telogen

• Hair remains anchored but inactive

ASAHRS teaches structured follow-up protocols to stabilize telogen-dominant scalps using medical therapy, nutraceuticals, and non-invasive bio-restoration.

4. Exogen Phase (Shedding Phase)

The exogen phase is when hair sheds naturally.

• Often overlaps with telogen

• Normal daily shedding: 50–100 hairs

• Excessive shedding signals:

  • Androgenetic alopecia

  • Telogen effluvium

  • Genetic sensitivity

Understanding exogen dynamics is essential before planning surgical restoration—one of the critical evaluation skills taught in ASAHRS fellowships.

Why the Stages of Hair Growth Matter in Hair Restoration

Hair restoration success depends on:

• Accurate diagnosis of hair-cycle disruption

• Differentiating reversible vs progressive loss

• Timing surgical and non-surgical interventions

• Designing natural hairlines that age gracefully

The ASAHRS Fellowship Program trains physicians to integrate hair growth biology with real-world clinical decision-making.

Learn more about the ASAHRS Fellowship Program.

Overview of ASAHRS Fellowship Programs

The American Society of Aesthetic & Hair Restoration Surgeons (ASAHRS) is headquartered in Orlando, Florida, and is globally recognized for setting high standards in education, ethics, and innovation.

Core Fellowship Programs

1. Fellowship in Advanced Hair Restoration (Primary Program)

• Duration: 4 days (intensive, hands-on)

• Training Includes:

  • Manual, motorized, automated & robotic FUE

  • Live surgery participation

  • Hairline design and donor management

  • Genomic-based treatment planning

• Tuition: $3,450

• Suitable for: Physicians, nurses, medical aesthetic practitioners

2. Non-Invasive Hair & Skin Bio-Restoration Fellowship (NEW)

• Duration: 2 days

• Focus: Device-based, non-surgical restoration

• Key Technologies:

  • Ultrasonic & pneumatic transdermal delivery

  • Cold plasma scalp bio-stimulation

  • Peptide and growth factor protocols

  • DNA-based personalization

3. Fellowship in 360° Aesthetic Practice

A comprehensive program combining:

• Surgical and non-surgical hair restoration

• Non-invasive body sculpting

• Facial rejuvenation (Botulinum toxin, fillers, lasers)

• Practice marketing and patient acquisition strategies

ASAHRS Fellowship Curriculum

The ASAHRS curriculum is competency-driven and structured around six core learning objectives:

Key Curriculum Highlights

• Perform FUE confidently with minimal transection

• Design natural, age-appropriate hairlines

• Integrate surgical and non-surgical protocols

• Apply non-invasive bio-restoration techniques

• Use genetics for precision medicine

• Market ethically and professionally

Advanced Genomics Training

A distinguishing feature of ASAHRS is its DNA and genomics integration, teaching physicians to:

• Interpret hair-loss genetic markers

• Predict treatment response

• Customize medical and surgical plans

• Explain genomic findings to patients clearly

Fellowship Pathway & Certification Stages

Stage 1: Fellowship Foundation Certificate (ASAHRS-FFC)

• 4-day intensive training

• No exam required

• Covers theory, FUE, AI tools, genomics, and consultations

Stage 2: ASAHRS Board Certification

• Written + oral exams

• Valid MD or DO license required

• Signals excellence, ethics, and safety

View Exam Dates and Certification details.

Stage 3: Fellow of ASAHRS (F-ASAHRS)

• Clinical competency evidence

• Real-world case documentation

• Simulation labs and OSATS reviews

• Prestigious international credential

Advanced Technology Used at ASAHRS

ASAHRS fellows train with:

• HARRTS FUEsion X 5.0 robotic systems

• AI-based hairline visualization

• AR surgical planning tools

• Genomic analysis platforms

• Cold plasma and ultrasonic delivery devices

This technology future-proofs physicians in an evolving field.

Eligibility Criteria

ASAHRS programs are open to:

• Physicians (MD or equivalent)

• Registered nurses and licensed healthcare professionals

• Unrestricted medical license in good standing

No prior hair restoration experience is mandatory.

Fellowship Tuition & Payment Options

Tuition Overview

• Advanced Hair Restoration Fellowship (4 days): $3,450

• Board Certification Exams: $5,000 total

• Retake Fees:

  • Written: $495

  • Oral: $895

Payment Options

• 6–24 month installment plans

• Easy financing via Affirm

• Flexible scheduling if dates are missed

ASAHRS Fellowship Locations & Training Venues

ASAHRS uses state-of-the-art facilities equipped with AI, AR, and robotic systems.

Training Locations

• Orlando, Florida (HQ):7380 West Sand Lake Road, Doctor Phillips, Orlando, FL 32819

• Beverly Hills, California:8920 Wilshire Blvd, Suite 604, Beverly Hills, CA 90211

• Buffalo, New York:777 Maple Rd, Suite 400, Buffalo, NY

• Boca Raton, Florida:7301A W Palmetto Park Rd, #303C, Boca Raton, FL

• Miami, Florida:8200 W 33rd Ave #8, Hialeah, FL 33018

• Las Vegas, Nevada:3195 St Rose Pkwy, Henderson, NV 89052

Program Dates

ASAHRS runs programs year-round across the U.S.

• December 12–15, 2025 – Buffalo, NY

• January 23–26, 2026 – Beverly Hills, CA

• February 20–23, 2026 – Miami, FL

• April 03–06, 2026 – Las Vegas, NV

• May 01–04, 2026 – Buffalo, NY

See updated Program Dates.

Certification & Career Opportunities

ASAHRS credentials enhance:

• Patient trust and credibility

• International recognition

• Practice differentiation

• Ethical and safe practice standards

Certified physicians gain a competitive edge in both surgical and non-surgical hair restoration markets.

Physician Reviews & Real Testimonials

Read verified Physician Reviews.

Real Testimonials

• Dr. Ilyas Mahjoub: “The training I received from the ASAHRS faculty members was truly world-class. It completely changed my perspective towards my hair restoration practice.”

• Dr. Ricardo Rodriguez: “What I learned in just one week would have otherwise taken me years. The course is optimally designed and paced.”

• Dr. Steve Carlson: “The hands-on training on life-like simulators allowed me to practice all my skills without restrictions.”

Contact Information

American Society of Aesthetic and Hair Restoration Surgeons (ASAHRS)

• Address: 7380 West Sand Lake Road, Doctor Phillips, Orlando, FL 32819

• Phone: 321-204-7431

• Email: contact@asahrs.com

• Website: https://www.asahrs.com/

Conclusion

Mastering the stages of hair growth is essential for delivering safe, ethical, and effective hair restoration outcomes. The ASAHRS Fellowship bridges biological science with advanced technology, genomics, and hands-on mastery—creating confident, future-ready physicians.

Whether your goal is surgical excellence, non-invasive innovation, or full aesthetic practice expansion, ASAHRS provides the education, credentials, and global credibility to excel.

Medical Information Notice/ Medical Information Disclaimer

This content is provided for general educational purposes only and reflects the clinical experience and protocols followed at ASAHRS. It is not a substitute for professional medical advice, diagnosis, or treatment. Patients are advised to consult a qualified hair restoration specialist for personalized recommendations.