Androgenetic Alopecia (AGA)
Also known as Male Pattern Baldness or Female Pattern Baldness.​
The most common cause of hair loss in men and women.
Androgenetic alopecia (pattern hair loss) is a progressive condition in which susceptible hair follicles gradually shrink in response to androgens—particularly dihydrotestosterone (DHT). This leads to shorter, finer hairs and, over time, visible thinning across characteristic areas of the scalp.
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It is the leading cause of hair loss worldwide, with well-established patterns:
In men: recession at the temples and crown
In women: diffuse thinning over the top of the scalp with preservation of the frontal hairline
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While extremely common, it is often misunderstood. Androgenetic alopecia is not simply “cosmetic”—it is a biological process with a defined mechanism, and one that can be assessed and managed based on current scientific evidence.
What Is Actually Happening in Androgenetic Alopecia?
Androgenetic alopecia is driven by a process known as follicular miniaturisation—a gradual transformation of healthy, thick terminal hairs into finer, shorter hairs over successive growth cycles.
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At a biological level, three key processes are involved:
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1. Genetic Sensitivity to Androgens
Hair follicles in certain areas of the scalp (particularly the top) are genetically programmed to be more sensitive to androgens such as dihydrotestosterone (DHT).
This sensitivity—not the absolute level of hormones—is what drives the condition.
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2. Progressive Shortening of the Growth Phase
Each hair grows in cycles. In androgenetic alopecia:
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The anagen (growth) phase becomes shorter
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The telogen (resting/shedding) phase becomes proportionally longer
Over time, hairs do not grow long enough or thick enough to maintain coverage.
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3. Gradual Follicle Miniaturisation
With each cycle:
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Hair shafts become thinner and less pigmented
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Follicles produce vellus-like hairs instead of terminal hairs
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Eventually, some follicles may become dormant
This is why patients often notice:
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“My hair is still there—but it’s thinner”
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“My scalp is becoming more visible”
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“My hair won’t grow as long as it used to”
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It is a Patterned Process — Not Random Hair Loss
One of the defining features of androgenetic alopecia is that it follows predictable, anatomically defined patterns:
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The frontal scalp and crown are typically affected
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The back and sides are relatively resistant
This reflects underlying biological differences in follicle behaviour across the scalp.
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Understanding this process is key—because effective management is not about “stimulating hair growth” in general, but about targeting the specific biology driving follicle miniaturisation.
Who Does Androgenetic Alopecia Affect — and When Does It Start?
Androgenetic alopecia can affect both men and women, but the age of onset, pattern, and progression differ.
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In Men
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Can begin as early as the late teens or early 20s
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Often first noticed as:
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Recession at the temples
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Thinning at the crown
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Progression is typically gradual but continuous
By age 50, around 50% of men will have clinically significant androgenetic alopecia, with prevalence increasing steadily with age.
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In Women
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Usually presents later than in men, most commonly:
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From the 30s onwards
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Increasing around perimenopause and menopause
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Typically appears as:
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Diffuse thinning over the top of the scalp
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With preservation of the frontal hairline
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By age 50, approximately 25–40% of women are affected to some degree.
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Early vs Late Onset — Why It Matters
Earlier onset often indicates a stronger genetic predisposition and may be associated with:
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Faster progression
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Greater lifetime hair loss
Later onset tends to be more gradual, particularly in women, but can still become significant over time.
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A Lifelong Process, Not a Sudden Event
Androgenetic alopecia does not typically present as sudden shedding. Instead, patients often describe:
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“My hair has been getting thinner over years”
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“My parting is widening”
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“It doesn’t feel as thick as it used to”
This slow progression is why it is often noticed late—but biologically active much earlier.
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The next step is distinguishing androgenetic alopecia from other causes of hair loss—because not all thinning follows this pattern, and accurate diagnosis is essential before considering treatment.
How is Androgenetic Alopecia Diagnosed?
Diagnosing androgenetic alopecia should be done by a Dermatologist. Diagnosis is primarily clinical, but accurate confirmation requires a structured assessment. It is important to remember that not all hair thinning is androgenetic alopecia, and successful management depends on getting the diagnosis right.
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1. Clinical History
A detailed history often provides the first clues:
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Gradual onset over months to years
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Family history of similar hair loss
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Absence of sudden shedding (which can suggest conditions like telogen effluvium)
In women, it is also important to ask about:
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Menstrual history
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Menopause
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Symptoms of androgen excess (e.g. acne, hirsutism)
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2. Pattern Recognition
Androgenetic alopecia follows predictable patterns:
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Men: recession at the temples and thinning at the crown
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Women: widening of the central part with diffuse thinning over the top
These patterns can be helpful in distinguishing from other conditions, but it is not always clear.
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3. Trichoscopy (Scalp Dermoscopy)
This is one of the most useful tools in clinic.
Typical findings include:
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Variation in hair shaft diameter (miniaturisation)
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Increased number of thin, vellus-like hairs
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Reduced density in affected areas
These features are considered hallmarks of androgenetic alopecia and can often confirm the diagnosis without the need for biopsy.
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4. Hair Pull Test (Supportive, Not Diagnostic)
A gentle traction test may be performed:
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Usually negative or only mildly positive in androgenetic alopecia
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Strongly positive results suggest alternative diagnoses (e.g. active shedding disorders)
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5. Blood Tests — When Indicated
Blood tests are not required to diagnose androgenetic alopecia, but may be used to:
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Exclude other contributing factors (e.g. iron deficiency, thyroid dysfunction)
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Assess hormonal profiles in selected female patients
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6. When Is a Biopsy Needed?
Rarely required, but considered if:
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The diagnosis is unclear
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There are signs of scarring or inflammation
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Hair loss is atypical or rapidly progressive
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Key Point
Androgenetic alopecia is usually confirmed through a combination of:
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History
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Pattern recognition
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Trichoscopic findings
Not every patient with thinning hair has androgenetic alopecia—and not every androgenetic alopecia patient presents in a textbook way.
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Once the diagnosis is confirmed, the next question becomes: what can realistically be done—and what does the evidence actually support?
Which Treatments for Androgenetic Alopecia Actually Work?
There are only a small number of treatments with credible clinical evidence for androgenetic alopecia. Most fall into two categories:
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Targeting the underlying biology (androgens and follicle miniaturisation)
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Supporting follicle function and hair cycling
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Understanding this distinction is key—because many widely marketed treatments do neither.
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Treatments with Strong Evidence
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1. Minoxidil (Topical)
Minoxidil
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Widely studied and licensed for androgenetic alopecia
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Prolongs the anagen (growth) phase and increases hair diameter
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Works in both men and women
What to expect:
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Stabilisation of hair loss is more common than dramatic regrowth
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Results take 3–6 months to become noticeable
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Continued use is required to maintain effect
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2. Finasteride (Oral, Men)
Finasteride
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Reduces conversion of testosterone to DHT, the key driver of follicle miniaturisation
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Strong evidence for slowing progression and improving density in men
What to expect:
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Most effective for maintaining and thickening existing hair
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Requires ongoing use
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Requires careful discussion of risks and suitability
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3. Platelet-Rich Plasma (PRP)
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Uses concentrated growth factors derived from the patient’s own blood
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Increasing body of evidence supports improvements in hair density and thickness
What to expect:
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Works best in early to moderate androgenetic alopecia
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Requires a course of treatments and maintenance
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Outcomes vary depending on protocol and patient factors
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4. Low-Level Laser Therapy (LLLT)
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Medical-grade light devices (e.g. laser caps/helmets)
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Thought to improve cellular energy production within follicles
What to expect:
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Modest but measurable improvements in some patients
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Requires consistent, long-term use
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Often used as an adjunct rather than standalone treatment
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A Realistic Perspective
No treatment “cures” androgenetic alopecia.
The goals are typically to:
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Slow or stabilise progression
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Improve hair thickness and density
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Preserve existing follicles for as long as possible
Early intervention generally leads to better outcomes—because once follicles are lost or severely miniaturised, they are more difficult to recover.
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The key question then becomes: which of these treatments is appropriate for you, based on your stage, pattern, and goals?
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Which Treatment Is Right for You?
There is no single “best” treatment for androgenetic alopecia. The right approach depends on stage of hair loss, pattern, biology, and personal preferences. A structured, individualised plan is far more effective than a one-size-fits-all approach.
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Step 1: Identify Your Stage
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Early Thinning
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Subtle reduction in density
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Hair still present but finer
Typical approach:
Goal: Stabilise early and preserve as much hair as possible
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Moderate Hair Loss
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Visible scalp through hair
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Noticeable recession or widening part
Typical approach:
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Combination therapy:
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Minoxidil
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Finasteride (men, if appropriate)
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PRP course + maintenance
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Adjuncts (LLLT, microneedling)
Goal: Slow progression and improve density where follicles are still active
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Advanced Hair Loss
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Large areas of thinning or baldness
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Long-standing follicle miniaturisation
Typical approach:
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Medical treatments may still help preserve remaining hair
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Consideration of:
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Hair transplantation
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Cosmetic options (fibres, scalp micropigmentation)
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Goal: Realistic improvement + preservation, not full restoration
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Step 2: Consider Your Biology
Not all patients respond in the same way. Key factors include:
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Genetic sensitivity to androgens
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Duration of hair loss
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Age and hormonal status
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Scalp health and follicle viability
This is why two people with similar-looking hair loss can respond very differently to the same treatment.
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Step 3: Define Your Goals
Different patients want different outcomes:
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Stabilisation only → often achievable with medical therapy alone
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Thickening and cosmetic improvement → combination approaches
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Maximal restoration → may involve surgical + medical strategies
Clarity here avoids unrealistic expectations and guides appropriate treatment selection.
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A Practical Framework
In most cases:
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Foundation:
Evidence-based medical therapy (e.g. minoxidil ± finasteride) -
Advanced options:
Transplant or cosmetic camouflage when needed
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Key Point
The earlier treatment is started, the more options are available—and the better the likely outcome.
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If you’re unsure where you sit, the most useful first step is a structured assessment—looking at pattern, progression, and follicle behaviour—so that any treatment plan is based on evidence, not guesswork.