The Role of Hormones and DHT in Hair Loss

Hair loss can feel personal and puzzling, especially when it doesn’t seem to match your health, age, or habits. The missing link for many people is hormones—particularly how dihydrotestosterone (DHT) interacts with hair follicles over time. Once you understand the hormonal pathways and how they differ between men and women, the options for diagnosis and treatment make a lot more sense. I’ve spent years working with dermatologists and trichologists, interviewing patients, and combing through clinical research; below is a practical guide that blends science with real-world strategies to help you get your hair—and confidence—back on track.

How Hair Growth Works: The Cycle Behind the Shedding

Hair follicles cycle through three phases:

• Anagen (growth): Lasts 2–6+ years. About 85–90% of scalp hairs are in anagen at any time. Average growth is ~1–1.3 cm per month.

• Catagen (transition): A brief 2–3 week phase where growth stops and the follicle shrinks.

• Telogen (resting/shedding): Lasts ~2–4 months. About 10–15% of hairs are in telogen, and 50–100 hairs are shed daily under typical conditions.

Most hair loss conditions either shorten anagen or push more hairs into telogen. Androgen-driven hair loss (androgenetic alopecia, or pattern hair loss) does both and also leads to “miniaturization”—hairs become thinner, shorter, and less pigmented over successive cycles.

Meet the Hormones: Who’s Involved and What They Do

Testosterone and DHT: The Core Players

• Testosterone circulates in your bloodstream and enters hair follicles, where the enzyme 5-alpha reductase (5-AR) converts some of it into DHT.

• DHT binds to androgen receptors in the follicle’s dermal papilla cells and, in genetically susceptible individuals, shortens anagen and initiates miniaturization.

• There are two main 5-AR isoenzymes: Type 2 (more active in hair follicles and the prostate) and Type 1 (found in skin and sebaceous glands). This matters for treatment because medications target these enzymes differently.

Numbers to have in mind:

• Finasteride (blocks mainly 5-AR type 2) can reduce serum DHT by ~65–70% and scalp DHT by ~60%.

• Dutasteride (blocks both type 1 and 2) can reduce serum DHT by up to ~90% and scalp DHT more robustly than finasteride.

Estrogen and Progesterone: The Modulators

Estrogen tends to prolong anagen and increase hair diameter, which is why hair often looks thicker during late pregnancy when estrogen is high. After delivery, estrogen falls sharply and a synchronized shift of many follicles into telogen causes postpartum shedding. Progesterone has mild anti-androgenic properties and, in some contexts, can balance the effects of DHT.

Thyroid Hormones: The Metabolic Governors

Hypothyroidism and hyperthyroidism both disrupt the hair cycle. People often notice dry, brittle hair and diffuse shedding. Fixing thyroid imbalances (TSH and free T4 targets) can dramatically improve shedding within months.

Cortisol (Stress Hormone)

Chronic stress increases cortisol and can push follicles into telogen. While stress alone doesn’t cause patterned miniaturization, it often worsens shedding and amplifies what DHT is already doing. Many patients report a noticeable uptick in hair fall 2–3 months after intense stress.

Prolactin

High prolactin can contribute to hair problems and sometimes indicates a pituitary issue or medication side effect. It’s not the primary driver of pattern loss but can increase shedding and disrupt cycles.

Insulin and IGF-1

Insulin resistance (common in metabolic syndrome and polycystic ovary syndrome, PCOS) can increase free androgens by lowering sex hormone–binding globulin (SHBG). That can intensify DHT signals to hair follicles, particularly in women with PCOS. Diet and lifestyle changes that improve insulin sensitivity often help hair density over 6–12 months.

DHT and Pattern Hair Loss: The Core Mechanism

The Biology of Miniaturization

DHT binds androgen receptors in the dermal papilla, altering cell signaling. Research points to increased TGF-β, DKK-1, and PGD2—signals that shorten anagen, promote catagen, and inhibit growth. Over time, the follicle shrinks and produces thinner hairs until it can no longer produce a visible strand.

Genetics and Scalp Sensitivity

You can have “normal” DHT levels and still lose hair if your follicles are genetically sensitive. Variants in the androgen receptor (AR) gene and genes affecting 5-AR activity play a role. That’s why one person can keep a thick head of hair despite high androgens while another thins early with average hormone levels.

Scalp geography matters:

• The temples and vertex tend to have more androgen receptor activity and 5-AR expression in susceptible people.

• The occipital scalp (back of the head) is relatively resistant, which is why it’s commonly used for hair transplant donor grafts.

Men vs. Women: Different Patterns, Shared Pathways

• Men: Male pattern hair loss affects about 30–50% of men by age 50 and up to 80% by age 70. It often starts at the hairline and crown.

• Women: Female pattern hair loss affects roughly 30–40% by age 50, increasing with age. Women typically experience diffuse thinning over the crown with a preserved frontal hairline. Systemic androgens may be normal; the follicles just respond more vigorously to them. Menopause, with its drop in estrogen, can unmask or accelerate thinning.

Life Stages and DHT

• Puberty: Surge in androgens can start the pattern—especially in genetically predisposed teens and young adults.

• Pregnancy/Postpartum: High estrogen protects; the postpartum drop can trigger telogen effluvium. If you already have follicular sensitivity, postpartum shedding can unveil early pattern loss.

• Menopause: Lower estrogen may tip the balance toward androgen effects, accelerating miniaturization in women.

Other Hormone-Related Hair Loss Patterns

Telogen Effluvium (TE)

TE is a diffuse shedding condition triggered by physiological or emotional stressors: illness, high fever, surgery, crash diets, iron deficiency, thyroid issues, or significant life stress. Shedding typically starts 2–3 months after the trigger, and daily hair loss can jump to 200–300 hairs. TE doesn’t miniaturize the follicle; it shifts more hairs into telogen. Once the trigger resolves, hair density generally rebounds in 6–12 months.

Postpartum Shedding

Usually begins 2–4 months after delivery, peaks around 4 months, and resolves by 9–12 months. If thinning persists beyond a year, investigate iron status, thyroid function, and underlying pattern loss.

PCOS and Androgen Excess

Women with PCOS may have elevated androgens, insulin resistance, acne, and irregular periods. Hair loss is often a mix of androgen-driven miniaturization and TE from metabolic stress. Addressing insulin resistance (diet, exercise, metformin) and using anti-androgens can be effective.

Thyroid Disorders

Both hypo- and hyperthyroidism cause diffuse shedding, coarse/brittle hair, and sometimes eyebrow thinning. Correcting thyroid levels typically restores healthier growth in several months.

Anabolic Steroids and Testosterone Therapy

Exogenous androgens (testosterone cypionate, anabolic steroids) increase DHT and can rapidly accelerate hair loss in men predisposed to pattern baldness. Some men on testosterone replacement therapy add a 5-AR inhibitor to blunt this effect, but this strategy requires a thoughtful risk–benefit discussion with a clinician.

How to Tell What You’re Dealing With

Practical At-Home Checks

• Pattern: Receding hairline, temple thinning, and vertex loss suggest DHT-driven loss. Diffuse shedding across the whole scalp suggests TE.

• Miniaturization: Look for progressively finer hairs, especially in a widening part (women) or crown (men).

• Hair pull test: Gently tug a small bundle of hairs. If more than 6–8 come out from a 60-hair bundle, shedding is elevated.

• Photos: Take standardized photos (same lighting, angle, distance) every month. The camera often sees change earlier than you do.

What to Discuss With a Clinician

Bring a timeline of your hair changes, recent stressors, diet changes, pregnancies, menstrual history, medications, and family history. Mention any scalp symptoms (itching, scaling, tenderness).

Useful Lab Work (tailored to symptoms)

• Thyroid panel: TSH, free T4.

• Iron status: Ferritin, iron, TIBC, transferrin saturation. Aim for ferritin above 40–70 ng/mL for optimal growth if you have hair loss.

• Vitamin D (25-OH D).

• For women with signs of androgen excess: total and free testosterone, DHEA-S, SHBG, LH/FSH ratio, prolactin.

• Metabolic markers: fasting insulin, glucose, lipid panel if insulin resistance is suspected.

A dermatologist or trichologist may also use trichoscopy (dermoscope imaging) to confirm miniaturization or, in uncertain cases, a small scalp biopsy to differentiate between androgenetic alopecia and other causes (e.g., scarring alopecias).

Treatments That Target Hormones and DHT

No single approach fits everyone. The best outcomes usually come from a layered plan: reducing DHT influence, supporting the hair cycle, calming inflammation, and fixing underlying deficiencies.

5-Alpha Reductase Inhibitors (Men and Select Women)

• Finasteride (oral, typically 1 mg daily for hair): Reduces conversion of testosterone to DHT. Slows loss in most men and regrows hair in many, especially at the crown. Expect to evaluate results at 6–12 months; photos matter.

• Dutasteride (0.5 mg, sometimes used off-label for hair): More potent for DHT suppression by blocking both 5-AR isoenzymes. Helpful for men who don’t respond to finasteride or who have aggressive loss.

Topical finasteride/dutasteride formulations exist and may reduce systemic exposure, though some absorption still occurs. Early data and real-world experience suggest topical finasteride can be effective, particularly when combined with minoxidil.

Cautions:

• Potential side effects include reduced libido, erectile dysfunction, mood changes, and gynecomastia. These are uncommon but real; discuss with your clinician.

• Women who are pregnant or may become pregnant must avoid handling crushed or leaking tablets or topical solutions—these drugs can cause fetal abnormalities.

• For women, oral finasteride and dutasteride are generally reserved for postmenopausal patients or used with reliable contraception under specialist care.

Professional insight: In men, starting earlier yields better density preservation. In clinics I’ve followed, men who combine a DHT blocker with minoxidil and anti-inflammatory scalp care tend to stabilize faster and hold gains longer.

Androgen Receptor Blockers (Mostly for Women)

• Spironolactone (50–200 mg daily): Blocks androgen receptors and reduces androgen production. Often used in women with signs of androgen excess or PCOS. Improvement typically appears after 3–6 months.

• Cyproterone acetate, flutamide, and bicalutamide: Used in select regions/cases, often with more monitoring for side effects (liver toxicity with flutamide, for example). These are specialist prescriptions.

Cautions:

• Spironolactone can cause menstrual irregularities, breast tenderness, fatigue, and increased urination; it’s potassium-sparing, so labs may be checked.

• Effective contraception is recommended, as anti-androgens can affect a male fetus.

Minoxidil: Not Hormonal, Still Foundational

• Topical minoxidil (2–5% foam or solution): Increases anagen duration and follicle size. Works synergistically with anti-androgens because it promotes growth while DHT blockers protect follicles from miniaturization.

• Oral minoxidil (very low dose, off-label): An option for those who don’t tolerate topical forms. Requires monitoring because it can affect blood pressure and cause edema or increased body hair.

Real-world note: Many patients quit early because of a temporary “shedding phase” when starting minoxidil. This is usually a sign that follicles are shifting cycles. It tends to settle after 6–8 weeks.

Anti-Inflammatory and Antifungal Scalp Care

• Ketoconazole 1–2% shampoo (2–3x/week): Helps with dandruff/seborrheic dermatitis and may have mild anti-androgenic action in the scalp. I often see better outcomes when ketoconazole is part of the routine, especially for those with oily, itchy scalps.

• Gentle, frequent cleansing if you have oily scalp. Excess sebum may carry DHT metabolites and feed Malassezia yeast, increasing inflammation.

Nutrition and Metabolic Support

• Iron: Low ferritin correlates with increased shedding; aim for ferritin above 40–70 ng/mL if you have hair loss symptoms. Work with a clinician on iron dosing and causes of deficiency.

• Protein: Hair is protein-hungry. Target 1.0–1.2 g/kg/day if you’re active, more if you’re on a low-calorie diet. Crash dieting is a major trigger of TE.

• Vitamin D: Replete if low. Many hair loss patients show levels <30 ng/mL.

• Zinc, selenium, B12: Replace deficiencies when confirmed. Routine mega-dosing isn’t helpful.

• Biotin: Unless you’re deficient (rare), extra biotin won’t regrow hair and can interfere with lab tests (including thyroid and cardiac assays).

• Insulin resistance: A Mediterranean-style diet, resistance training, and sleep optimization reduce insulin and may lower free androgens over time. Women with PCOS often notice less shedding and better texture after 3–6 months of consistent lifestyle changes.

Low-Level Laser Therapy (LLLT), Microneedling, PRP

• LLLT devices (home caps/combs) have moderate evidence for improving density over 4–6 months when used consistently.

• Microneedling (0.5–1.5 mm rollers or pens weekly/biweekly) can stimulate growth factors. Combining with topical minoxidil may improve absorption; be gentle to avoid irritation.

• PRP (platelet-rich plasma) injections can improve hair caliber and density in many cases, though response varies. Typically done in a series (e.g., monthly for 3 months, then maintenance).

Hair Transplantation

For advanced pattern loss with stable donor areas, modern follicular unit extraction (FUE) or strip methods can produce natural results. Transplantation doesn’t stop miniaturization in native hairs; continuing medical therapy to protect non-transplanted follicles is standard in good clinics.

What About Supplements and “Natural” DHT Blockers?

• Saw palmetto: Some small studies suggest mild anti-androgenic effects. Results, if any, are less robust than finasteride/dutasteride. Consider as an adjunct, not a replacement, especially for men with progressive loss.

• Pumpkin seed oil: Limited evidence suggests it may modestly improve hair density.

• Caffeine and rosemary oil: Early data suggest they might help stimulate follicles. They can be part of an overall routine, but don’t expect them to counter strong androgenic drive alone.

When I audit regimens that rely only on supplements, results are usually underwhelming unless the underlying issue is a deficiency or mild TE. Supplements work best when layered with evidence-based therapies.

Side Effects, Safety, and Smart Monitoring

• Finasteride/dutasteride: Sexual side effects are uncommon but real. Discuss risks, start low if you’re cautious, and reassess at 3–6 months. A small subset reports mood changes; stop and consult your clinician if this occurs. Women of childbearing potential need contraception and specialist guidance for any anti-androgen therapy.

• Spironolactone: Monitor blood pressure and, in some cases, potassium. Using with a reliable contraceptive is prudent.

• Minoxidil: Topical can irritate; switch to foam or lower frequency as you adjust. Oral low-dose minoxidil requires medical oversight.

• Lab interference: Biotin can skew test results—stop supplementing for at least 48 hours (often a week is suggested) before blood tests, depending on lab guidance.

Common Mistakes That Stall Progress

• Quitting too soon: Meaningful change usually shows at 6–12 months, not 4 weeks. Photos help you stay objective.

• Ignoring scalp inflammation: Flaky, itchy scalps worsen shedding. A medicated shampoo routine is a small habit with big payoff.

• Chasing exotic supplements instead of fixing basics: Iron deficiency, uncontrolled thyroid issues, and insulin resistance will overpower fancy serums.

• Using minoxidil “here and there”: Consistency matters. Apply as directed daily (topical) or take oral doses as prescribed.

• Skipping sun/scalp protection: UV exposure and burns can inflame the scalp. Hats and non-greasy SPF sprays help.

• Not protecting transplanted results with maintenance therapy: A transplant is not a cure for androgen sensitivity.

A Step-by-Step Plan You Can Start Now

1) Document your baseline

• Take clear photos: front, sides, crown, and part line under consistent lighting.

• Note shedding estimates, scalp symptoms, and recent triggers (illness, diet changes, childbirth, stress).

2) Triage obvious triggers

• If shedding spiked after a crash diet, major stress, or illness, address that first.

• Treat dandruff/itch: Start ketoconazole 1–2% shampoo 2–3x/week and a gentle daily shampoo on other days.

• Stop tight hairstyles and harsh chemical treatments.

3) Get basic labs (through your clinician)

• Thyroid (TSH, free T4), ferritin and iron panel, vitamin D.

• For women with acne/irregular cycles or hirsutism: total and free testosterone, DHEA-S, SHBG, LH/FSH, prolactin; consider PCOS assessment.

• If results show deficiencies or endocrine issues, correct them.

4) Decide on a DHT strategy if pattern loss is present

• Men: Consider finasteride 1 mg daily or topical finasteride. If progression is rapid or crown loss is significant, discuss dutasteride with a clinician.

• Women (postmenopausal or with reliable contraception): Discuss spironolactone or, in selected cases, finasteride/dutasteride with a specialist.

• Combine with topical or oral low-dose minoxidil unless contraindicated.

5) Layer supportive therapies

• Ketoconazole shampoo routine for scalp health.

• Nutrition: Adequate protein, iron repletion if low, vitamin D optimization.

• Address insulin resistance: Mediterranean-style diet, resistance training 2–3x/week, 7–9 hours of sleep.

• Optional add-ons: LLLT devices, weekly microneedling, PRP if budget allows.

6) Set a realistic timeline

• 6–8 weeks: Shedding may stabilize; scalp feels healthier.

• 3–4 months: Early regrowth signs (short, fine hairs) and better texture.

• 6–12 months: Visible density improvements on photos.

• 12–18 months: Maximal cosmetic change with medical therapy.

7) Review and refine

• Reassess every 3–4 months. If you’re not improving by month 6–9, consider dose adjustments, switching from finasteride to dutasteride (men), adding spironolactone (women), or evaluating PRP/transplant options.

Real-World Examples

• A 32-year-old man with a receding hairline and thinning crown: Finasteride 1 mg daily + 5% minoxidil foam + ketoconazole 2% shampoo. At 4 months, shedding decreased but not much density change; at 9 months, crown filled in on photos and hairline looked stronger with micro-regrowth. He stayed consistent and added LLLT at month 6 for an extra boost.

• A 28-year-old woman with PCOS and diffuse thinning: Spironolactone 100 mg daily + 5% minoxidil foam + iron supplementation (ferritin 18 ng/mL baseline) + insulin-sensitizing diet and strength training. She noticed less shedding by month 3, thicker ponytail by month 6, and visible density improvement by month 9. Addressing ferritin and insulin resistance was a turning point.

• A 45-year-old woman postmenopause with widening part: Topical finasteride-minoxidil combo + intermittent ketoconazole shampoo. With normal androgens but classic miniaturization, the topical route improved density over 9–12 months with fewer systemic concerns.

What the Data Says About Expectations

• Finasteride: Most men maintain or improve hair count at 1 year; improvements often continue up to 2 years, then plateau. Crown responds better than the frontal hairline, though early hairline improvements do occur.

• Dutasteride: Often stronger gains than finasteride for resistant cases.

• Minoxidil: Works for both sexes; daily use is key. Stopping leads to loss of gains in several months.

• Spironolactone: In women, significant reduction in shedding and density gains are common at 6–12 months, especially with PCOS or clinical signs of androgen excess.

• LLLT: Meta-analyses support modest but real gains, particularly as an adjunct.

• PRP: Many patients see improved hair caliber and density; results vary with technique and frequency.

Myths to Ignore

• “Hats cause baldness.” They don’t. Tight helmets can cause frictional breakage, but not androgenetic alopecia.

• “Masturbation or sex causes baldness.” No credible evidence supports this.

• “Shampooing daily causes hair loss.” It only reveals hairs already scheduled to shed.

• “Dandruff causes permanent hair loss.” Dandruff and seborrheic dermatitis can increase shedding via inflammation, but treating them restores normal cycling.

Special Notes for Specific Groups

• Athletes on anabolic steroids: If preserving hair is a priority, reconsider androgens or add medical therapy under supervision. Supra-physiologic androgens can overpower topical routines.

• People on testosterone therapy: Discuss a DHT-blocking strategy and monitor for changes with photos. Not everyone will lose hair, but predisposed individuals often notice acceleration.

• Postpartum mothers: Gentle scalp care, adequate protein/iron, and patience. If you’re breastfeeding, avoid systemic anti-androgens. Consider topical minoxidil after discussing with your OB/GYN; many wait until breastfeeding is complete.

• Men considering a transplant in their 20s: Work with a conservative surgeon and lock down a medical regimen to slow progression before moving follicles around. Transplanting too early without stabilization can lead to patchy patterns later.

Working With a Professional: What Good Care Looks Like

The best clinicians do three things:

• Confirm the diagnosis with trichoscopy and, if needed, a biopsy when the pattern isn’t obvious.

• Look for and treat underlying contributors (thyroid, iron deficiency, PCOS, medications).

• Personalize a plan, often combining a DHT strategy, minoxidil, scalp care, and lifestyle changes—then follow up with standardized photos.

In my experience collaborating with hair clinics, patients who commit to 12 months of purposeful, consistent therapy do far better than those who bounce between products. Routine and follow-up are underrated tools.

Practical Daily Routine Example

Morning:

• Gentle shampoo or water rinse; ketoconazole shampoo 2–3x/week.

• Apply topical minoxidil (foam dries faster) if using topical.

• Consider a lightweight scalp SPF if you’ll be outside.

Evening:

• Apply minoxidil if using twice daily.

• Take oral meds/supplements (finasteride/dutasteride/spironolactone, vitamin D, iron).

• 10–15 minutes of stress-reduction practice (breathwork, journaling, or a short walk).

Weekly:

• Microneedling session if part of your plan (avoid minoxidil for 24 hours after needling unless your clinician advises otherwise).

• LLLT sessions as per device instructions.

Monthly:

• Standardized photos.

• Quick check-in with yourself: shedding count, scalp comfort, any side effects.

Key Takeaways

• DHT doesn’t cause hair loss in everyone—genetic sensitivity of the follicles and local enzyme activity make the difference.

• Pattern hair loss shortens the growth phase and miniaturizes hair over time. Men and women show different patterns, but the pathways overlap.

• Serum hormone levels often look “normal” in people with pattern loss; local follicle sensitivity is the tipping point.

• Combine strategies: a DHT blocker (when appropriate), minoxidil, scalp anti-inflammatory care, and correction of thyroid/iron/metabolic issues.

• Expect a 6–12 month horizon for visible gains. Photos and patience are part of the therapy.

• If a plan isn’t working, don’t guess—adjust thoughtfully: dose, delivery (topical vs oral), add-ons like LLLT or PRP, or surgical options if stable.

Hair thrives on consistency and calm biology. When you dial down DHT’s impact, nourish the system, and support the scalp environment, most people see thicker, fuller hair over time. The science is on your side—build a plan, stick with it, and re-measure your progress with the same rigor you bring to any other goal.