Androgenetic Alopecia Explained: What to Know About Pattern Hair Loss

Androgenetic alopecia (AGA) is the most common type of hair loss that runs in families. It can happen to both men and women. Genes are the most important thing, but things like bad diet, long-term stress, smoking, and even pollution can make it worse.

It usually starts around puberty for men, when a hormone called DHT starts to shrink hair follicles that are sensitive. For women, it's a little less clear. Hair loss can happen at any age, but it usually gets worse after menopause, when male hormone levels naturally rise.

How to Recognize Androgenetic Alopecia

AGA, or androgenetic alopecia, mostly causes hair to thin over time, not fall out all at once. In areas that are sensitive to DHT, thick hairs turn into fine vellus hairs that often follow patterns like the Norwood or Ludwig scales.

AGA doesn't hurt. If you see redness, swelling, or pain, it could be a different condition like scarring alopecia that needs to be treated by a dermatologist right away.

It's normal to lose 100 to 150 hairs on days you shower. Hair loss caused by bad diet or chemotherapy is usually not related to AGA and could be a sign of a different problem.

Heavy shedding is often a sign of telogen effluvium, which can be caused by surgery, losing weight quickly (especially if you don't eat enough protein), stress, or illness.

AGA can look like or happen with other types of hair loss. For example, a person might have frontal fibrosing alopecia (FFA) at the hairline and AGA behind it.

Male Pattern Baldness: What to Look For

Androgenetic alopecia (AGA) is a type of hair loss that most people think of when they think of hair thinning. Male pattern baldness is the most common type of AGA.

About half of men have AGA by the time they are 50, and up to 80% by the time they are 80. It runs in families, but there isn't a clear genetic pattern. Research has found a link between multiple genes, but only the androgen receptor gene has been confirmed.

Even if you don't have a family history, you can still get AGA. Different people lose hair in different ways. Even identical twins can have different thinning because of stress, diet, or being outside.

Dihydrotestosterone (DHT), a byproduct of testosterone, is the main cause. It shrinks sensitive follicles, especially on the crown, front, and sometimes sides of the scalp.

AGA worsens over time and may speed up with testosterone or hormone use. Finasteride and minoxidil can slow loss and thicken hair. Once an area goes fully bald, only a transplant from DHT-resistant zones like the back of the scalp or beard can restore growth.

Female Pattern Baldness: How It Usually Starts

Hair thinning in women is more common than most people realize—almost as prevalent as male pattern baldness. The difference? It often flies under the radar. Why? Because women rarely go fully bald, so the signs are easier to miss.

But the numbers don’t lie. By the time a woman hits 30, about 1 in 8 will notice some hair loss. By 49, that’s 1 in 4. And as women move into their 60s, the number jumps to nearly 40%. That’s a lot of silent suffering. Many women don’t talk about it—whether it’s shame, confusion, or just the fear of seeming “less feminine.” After all, shaving your head like a guy? That’s not exactly seen as a socially acceptable option.

And while full-on baldness is rare—thanks to differences in hormones—female pattern hair loss (or AGA) is still very real. It just tends to be more complicated. Hormonal imbalances are often part of the picture. Think iron deficiency from periods, shifting estrogen levels, testosterone spikes, PCOS, menopause… it’s a lot.

That’s why a proper diagnosis isn’t just about what the mirror shows. Blood tests matter. A full lab panel alongside a physical exam gives the clearest picture.

Now, the good news: there are treatments that actually help. Minoxidil is a go-to. Spironolactone can be effective too. Finasteride? It works—but doctors tend to steer clear of it for women who could become pregnant because of the risk of birth defects. Postmenopausal women, though, might have it as an option in higher doses.

And yes, hair transplants aren’t just for men. For the right candidates, they can do more than restore hair—they can rebuild confidence.

How AGA Disrupts the Hair Growth Cycle

The hair growth cycle has four stages: anagen, catagen, telogen, and exogen. Hair grows during anagen, the longest phase, lasting 2 to 6 years. Catagen follows for 1 to 2 weeks, during which growth stops and the follicle shuts down.

Next is telogen, lasting 3 to 5 months, where about 10% of scalp hairs rest. Exogen overlaps with telogen and lasts 2 to 5 months as new hairs push out old ones, often during grooming.

In AGA, the anagen phase shortens—sometimes to under a year—and more hairs shift into telogen. Terminal hairs shrink into thin, colorless vellus hairs, eventually disappearing and leaving bald spots. Even smooth areas still contain dormant follicles.

This miniaturization is driven by DHT, a hormone made when testosterone converts via the 5-alpha-reductase enzyme. Finasteride blocks type 2 of this enzyme, reducing DHT by about 69%. Dutasteride blocks both type 1 and 2, lowering DHT even further.

These drugs can slow or reverse miniaturization by helping vellus hairs grow back into thicker strands. Once a spot is fully bald, the benefit declines, but nearby thinning areas may still respond.

How to Treat Androgenetic Alopecia

Minoxidil

Minoxidil likely helps by extending the hair’s growth phase and boosting blood flow to follicles. Regrowth tends to appear at the crown after about four months, but only with continued use—stopping it usually leads to hair loss again.

It’s most effective for early-stage AGA and small thinning spots. Available in 2% and 5% topical forms, the 5% version works better for men. One study showed 45% more regrowth with 5% than 2% after 48 weeks. Women also respond well, though the 5% version offers little added benefit and may increase facial hair.

A rare case involved a 37-year-old man who used 2% minoxidil for eight months and developed temporary vision problems due to central serous chorioretinopathy, which cleared up after stopping the treatment.

Oral minoxidil, though not FDA-approved for hair loss, is gaining popularity. The most common side effect is unwanted body hair, especially at 5 mg compared to 2.5 mg. Other possible effects include low blood pressure, fast heartbeat, fluid buildup, swollen legs, and changes in heart rhythm—usually linked to dose and reversibility.

Finasteride

Finasteride is an oral medication that blocks the enzyme converting testosterone to DHT. It's prescribed only for men, since it can cause birth defects if used during pregnancy.

It helps slow hair loss and boost regrowth, especially at the crown, and can also improve density at the hairline. Long-term use is needed—stopping it usually leads to more thinning. There's no proven benefit for postmenopausal women.

In a 10-year study, men over 30 or with advanced hair loss saw good results with 1 mg daily, often improving over time.

A large Japanese trial with 3,177 men confirmed it’s safe and effective. Of those who completed the study, 11.1% had strong regrowth, 36.5% moderate, and 39.5% mild. Side effects were rare (0.7%) and no long-term safety concerns were found.

Another study by Palloti noted a drop in sperm count and more abnormal sperm at six months, but most values returned to normal by 12–24 months. Erectile function stayed stable, with no clear link to sexual issues.

Other drugs

Several non-FDA-approved treatments show promise for treating androgenetic alopecia (AGA).

For women with high androgen levels, spironolactone and oral contraceptives may help reduce hair loss. Spironolactone can also benefit those with high blood pressure or excess aldosterone.

Topical ketoconazole may support regrowth by thickening hair shafts. Dutasteride blocks both types of 5-alpha-reductase, making it stronger than finasteride, though it's less studied in the U.S. Some experts still prefer finasteride due to fewer side effects and better hormonal balance.

A small study by Singh found that botulinum toxin injections improved scalp blood flow and hair growth in 8 of 10 men.

Low-level red light therapy devices like the HairMax LaserComb are FDA-cleared for safety, and one 26-week trial showed they may help, though effectiveness isn’t fully proven.

Latanoprost 0.1%, a glaucoma medication, increased hair density and color in men with mild AGA after 24 weeks.

Since AGA often overlaps with telogen effluvium, sudden hair loss should trigger checks for thyroid issues, anemia, or other treatable conditions.

For women, Dawson listed spironolactone, cyproterone acetate, finasteride, and minoxidil as options—early treatment usually leads to better results.

A Phase I trial using a single scalp injection of follistatin, KGF, and VEGF led to higher hair counts after one year with no side effects.

A Spanish study found that plasma rich in growth factors (PGRF) boosted anagen follicles by 6.2% and reduced telogen follicles by 5.1% after two monthly treatments.

Saw palmetto, taken orally or topically, blocks both 5-alpha-reductase types. A 24-week trial showed steady improvement in hair count with topical use.

Adipose-derived stem cells are also promising. A study by Fukuoka and Suga found better results when combined with finasteride, recommending long-term follow-up.

Surgical Care

Hair transplants have been used to treat androgenetic alopecia for over 40 years. Modern micrografting gives a more natural look than older plug techniques, but limited donor follicles remain a key challenge.

A 2009 review found high satisfaction with newer methods. However, patients with fewer than 40 follicular units per square centimeter in the donor area often see poor results.

Scalp reduction, once used to shrink bald areas, often caused scars that widened and became more noticeable.

Other Treatments

A South Korean study tested a 1550-nm fractional erbium-glass laser on 27 women with androgenetic alopecia. After 10 sessions over 20 weeks, 24 showed visible improvement. Two reported mild itching.

Jedlowski and Anthony found that this laser therapy can thicken hairs but doesn't increase hair count.

Hair weaving and hairpieces remain options to cover thinning or bald spots.

Hydrate Your Roots, Protect Your Future

Hair thinning might feel inevitable, but you're not powerless. Even if genetics play a role, small changes to your routine can make a big difference. From FDA-approved treatments like minoxidil and finasteride to natural helpers like Batana oil, there are options to explore.

While Batana oil isn’t a cure for androgenetic alopecia, its nourishing properties support scalp health, improve moisture retention, and help reduce breakage—creating a better foundation for any hair recovery plan.

No matter where you are in your hair loss journey, it’s worth taking action. A healthier scalp today can lead to stronger, fuller strands tomorrow. With guidance from a qualified specialist and the right combination of products, you can create a routine that supports long-term hair health.