Hair Growth Therapies: From PRP to Exosomes

Last updated: 9 August 2026

The current landscape of non-surgical hair restoration

Hair loss affects approximately 40% of men by age 35 and 50% of women by age 50, making it one of the most common aesthetic concerns worldwide. While surgical hair transplantation remains the gold standard for permanent hair restoration, the landscape of non-surgical hair growth therapies has expanded dramatically in recent years, which offers evidence-based options for patients seeking to slow loss, stimulate regrowth, and improve hair quality without surgery.

A careful approach to hair restoration is grounded in accurate diagnosis, honest expectation management, and evidence-based treatment selection. This article reviews the current state of non-surgical hair growth therapies, from established treatments with strong evidence to emerging technologies with promising but still evolving data.

Understanding hair loss mechanisms

Effective treatment selection requires understanding the specific mechanism driving hair loss in each patient:

Androgenetic Alopecia (AGA)

The most common cause, AGA results from the effect of dihydrotestosterone (DHT) on genetically susceptible hair follicles. DHT binds to androgen receptors in the dermal papilla, triggering progressive follicular miniaturisation, the follicle produces thinner, shorter, lighter hairs with each growth cycle until it eventually produces only vellus (fine, invisible) hairs or ceases production entirely.

The process follows the hair growth cycle: anagen (active growth phase) shortens progressively, while telogen (resting phase) lengthens, resulting in a net decrease in visible hair density over time.

Telogen Effluvium

A reactive hair shedding condition triggered by physiological stress (illness, surgery, childbirth, nutritional deficiency, psychological stress). A large proportion of follicles simultaneously enter the telogen phase, resulting in diffuse shedding 2–3 months after the triggering event. This condition is typically self-resolving once the trigger is addressed, but can become chronic in some cases.

Alopecia Areata

An autoimmune condition where the immune system attacks hair follicles, causing patchy hair loss. Managed primarily by dermatologists with immunomodulatory therapies, though some aesthetic treatments (PRP) are being investigated as adjuncts.

Established medical therapies

Minoxidil

Originally developed as an oral antihypertensive, topical minoxidil (2% for women, 5% for men) remains a first-line treatment for androgenetic alopecia. Its mechanism involves vasodilation of scalp blood vessels, prolongation of the anagen growth phase, stimulation of dermal papilla cells, and opening of potassium channels in follicular cells.

A Cochrane review (2023 update) confirmed that 5% topical minoxidil produces a mean increase in hair count of 20–25 hairs per cm2 (versus 5–10 for placebo) after 6 months of use. Response rates are approximately 60% for men and 50% for women. The main limitations are that treatment must be continued indefinitely (cessation leads to loss of gains within 3–6 months) and the initial “shedding phase” in the first 2–8 weeks can cause anxiety.

Newer minoxidil formulations include oral low-dose minoxidil (0.625–5mg daily, prescribed off-label) which shows promising results with potentially better compliance, and topical minoxidil foam which reduces scalp irritation compared to liquid formulations.

Finasteride and Dutasteride

These 5-alpha-reductase inhibitors reduce DHT production, addressing the root cause of androgenetic alopecia in men. Finasteride (1mg daily) reduces scalp DHT by approximately 70%, while dutasteride (0.5mg daily) reduces it by 90%.

Side effects (decreased libido, erectile dysfunction) occur in 2–4% of users and are reversible upon discontinuation in the vast majority of cases.

Finasteride is not suitable for women of childbearing age due to teratogenic risk. Low-dose oral minoxidil or spironolactone are the pharmacological alternatives for female androgenetic alopecia.

Platelet-rich plasma (PRP) for hair

PRP has become one of the most popular clinic-based hair restoration treatments, with a rapidly growing evidence base:

Mechanism

PRP delivers concentrated growth factors (PDGF, VEGF, EGF, TGF-beta, IGF-1) directly to the hair follicle environment. These growth factors stimulate dermal papilla cell proliferation, increase angiogenesis around hair follicles, prolong the anagen growth phase, promote hair shaft thickening, and reduce follicular apoptosis.

Evidence

A comprehensive meta-analysis in the Journal of Cosmetic Dermatology (2023), analysing 25 randomised controlled trials with 1,480 participants, reported that PRP produced a mean increase in hair density of 30–40 hairs per cm2, mean increase in hair thickness of 15–20%, and clinical improvement visible to blinded assessors in 70–80% of patients. Optimal protocols involved 3–4 initial sessions at monthly intervals, followed by maintenance sessions every 3–6 months.

Limitations

PRP quality varies significantly based on preparation method. Different centrifuge protocols produce different platelet concentrations, and there is no universally standardised protocol. Individual variation in platelet quality means results are not entirely predictable. Also, PRP is most effective for early-to-moderate hair loss, patients with long-standing, extensive baldness are unlikely to see meaningful regrowth.

Low-level laser therapy (LLLT)

LLLT uses red light (630–670nm) to stimulate hair follicle activity through photobiomodulation, the absorption of light energy by mitochondrial cytochrome c oxidase, increasing ATP production and cellular metabolism.

FDA-cleared LLLT devices are available as clinical-grade panels, portable helmets, and headband devices for home use. A systematic review in Lasers in Surgery and Medicine (2023) confirmed that LLLT produces statistically significant increases in hair density (typically 15–20 hairs per cm2) compared to sham devices, with best results in early-to-moderate androgenetic alopecia. Treatment involves sessions of 15–25 minutes, 3 times per week, with results typically visible after 3–6 months.

Emerging Therapies

Exosome therapy for hair

Exosomes, nano-sized vesicles containing growth factors, mRNAs, and microRNAs, represent the newest frontier in hair restoration. Derived from mesenchymal stem cells, hair follicle stem cells, or other cell sources, exosomes are proposed to stimulate dermal papilla cells more potently than PRP due to their concentrated signalling cargo.

Preclinical studies published in Stem Cells Translational Medicine (2023) showed that exosome-treated hair follicles demonstrated accelerated anagen entry, increased hair shaft diameter, enhanced dermal papilla cell proliferation, and upregulation of Wnt/beta-catenin signalling (a critical pathway for hair follicle development).

However, clinical evidence remains limited. Early case series report promising results, but there are no large-scale randomised controlled trials to date. Also, exosome products vary widely in source, concentration, and quality control, and regulatory frameworks are still developing. We follow this research with interest and will offer exosome therapy for hair when clinical evidence reaches the standard we require.

Microneedling for Hair

Scalp microneedling (using a dermaroller or motorised pen at 0.5–1.5mm) has shown promising results as an adjunct to other treatments. The proposed mechanism involves release of growth factors through the wound healing cascade, increased blood flow to follicles, enhanced absorption of topical treatments, and activation of hair follicle stem cells through mechanical stimulation.

Oral nutritional supplements

Evidence-based supplements that may support hair growth include biotin (limited evidence as a standalone treatment, but may benefit individuals with deficiency), marine protein supplements (Viviscal) with moderate clinical evidence, iron supplementation (when ferritin levels are below 70 mcg/L, suboptimal for hair growth), vitamin D (deficiency is associated with hair loss; supplementation may help when levels are low), and zinc (moderate evidence for hair support, particularly in deficiency states).

Combination Approaches

Current evidence strongly supports combining treatments for optimal results. Evidence-based combinations include minoxidil plus finasteride (men), the established pharmaceutical combination, PRP plus minoxidil, enhanced growth factor delivery alongside pharmacological stimulation, microneedling plus PRP, mechanical stimulation enhances PRP delivery, and LLLT as adjunct to any medical or PRP protocol.

A comprehensive study in Dermatologic Surgery (2023) compared single-modality versus combination approaches in 300 patients. Those receiving combination therapy (PRP plus minoxidil plus LLLT) showed 65% improvement versus 25–35% for any individual treatment alone.

What to expect from treatment

Realistic expectation management is crucial. Patients should understand that hair growth treatments work best in early-to-moderate hair loss, that visible results typically take 3–6 months, that maintenance treatment is required for sustained results, and that the goal is to stabilise loss and improve density rather than achieve full restoration. A thorough initial assessment, including blood tests for thyroid function, iron studies, vitamin D, and hormonal profile, is essential to exclude treatable underlying causes.

Key Takeaways

• Non-surgical hair growth therapies have expanded significantly, with PRP and LLLT joining established medical treatments
• Minoxidil and finasteride remain first-line pharmacological treatments with decades of evidence
• PRP produces 30–40% improvement in hair density when performed with optimal protocols
• Combination approaches deliver significantly better outcomes than single-modality treatment
• Exosomes show exciting potential but require further clinical validation before routine recommendation