Hair Loss: Causes, Treatments, and What Actually Works (2026 Guide)

Hair loss (alopecia) has many causes, but the most common by far is androgenetic alopecia — hereditary pattern hair loss affecting up to 80% of men and 50% of women by age 70 (Source: American Academy of Dermatology).

Other common causes include:

• Telogen effluvium: Temporary shedding triggered by stress, illness, surgery, pregnancy, or rapid weight loss. Usually resolves within 6-12 months.
• Alopecia areata: Autoimmune condition causing patchy hair loss. Affects 2% of the population.
• Nutritional deficiencies: Iron, vitamin D, zinc, and biotin deficiency can all contribute to hair thinning.
• Thyroid disorders: Both hypothyroidism and hyperthyroidism can cause diffuse hair loss.
• Medications: Chemotherapy, blood thinners, beta-blockers, retinoids, and some antidepressants can trigger hair loss.
• Traction alopecia: Caused by tight hairstyles pulling on hair follicles over time.

Only two treatments have FDA approval for hair loss:

Minoxidil (Rogaine)

• Available over-the-counter as 2% or 5% topical solution or foam
• Works for both men and women
• Must be used continuously — hair loss resumes if stopped
• Results visible in 3-6 months; peak results at 12 months
• Studies show 40-60% of users experience some regrowth

Finasteride (Propecia)

• Prescription-only oral medication (1mg daily)
• Approved for men only (contraindicated in women of childbearing age)
• Blocks DHT, the hormone that shrinks hair follicles
• Studies show 83-90% of men maintain hair count over 2 years
• Side effects (2-4% of users): decreased libido, erectile dysfunction — typically reversible upon stopping

Emerging treatments: Low-level laser therapy (LLLT) has FDA clearance (not approval) as a device. PRP (platelet-rich plasma) therapy shows promising results in clinical trials but is not yet FDA-approved for hair loss.

Several natural approaches have some scientific evidence, though none match the efficacy of FDA-approved treatments:

• Rosemary oil: A 2015 study in SKINmed Journal found rosemary oil comparable to 2% minoxidil after 6 months, with less scalp itching. More research needed.
• Saw palmetto: May block DHT similarly to finasteride but less potently. A 2020 meta-analysis found modest improvement in 60% of patients.
• Biotin supplements: Only effective if you have a biotin deficiency (uncommon). Routine supplementation in people with normal biotin levels has not shown benefit for hair growth.
• Iron supplementation: Only helps if ferritin levels are low (below 30 ng/mL). Get tested before supplementing.
• Pumpkin seed oil: One small 2014 study showed 40% improvement in hair count over 24 weeks.

If you suspect nutritional deficiencies are contributing to hair loss, upload your blood test results to WAYJET's Medical Report Analyzer for a detailed assessment of relevant markers.