INTRODUCTION
Many patients seek interventions to achieve thicker, fuller hair for aesthetic enhancement. Hair loss is a multifactorial condition impacting the majority of men and women worldwide during their lifetimes.1 Hair loss encompasses a spectrum of etiologies, including androgenetic alopecia (AGA), telogen effluvium, alopecia areata, and central centrifugal cicatricial alopecia.2 Beyond physical concerns, hair loss poses a psychosocial burden, associated with poor self-esteem, stress, anxiety, depression, and impaired quality of life.3,4
Hair loss is influenced by intrinsic and extrinsic factors. Intrinsic contributors include hormone imbalance, genetic predisposition, autoimmune processes, and alterations in follicular cycling.2 The androgen dihydrotestosterone (DHT), produced through 5α-reductase activity, is particularly implicated in follicular miniaturization and shortened anagen duration.5 Psychological stressors, including anxiety and depression, may precipitate hair loss.5,6 Extrinsic factors, including lifestyle patterns, pollution, and ultraviolet radiation, increase oxidative stress, inducing hair follicle apoptosis and atrophy.6
Current treatments aim to enhance aesthetic hair density and quality and prevent follicular loss. First-line therapies, minoxidil and finasteride, are effective in early disease, but their effects diminish over time and can result in adverse effects (AEs).7 Oral minoxidil can cause tachycardia, headaches, and hypertrichosis, while finasteride has been linked to permanent sexual dysfunction and depression.8,9 In advanced stages, patients often pursue procedural interventions, including intradermal injections of platelet-rich plasma (PRP) or follicular unit transplantation.10,11
Peptides have recently emerged as promising bioactive molecules in hair restoration therapy and aesthetic enhancement. Peptides are chains of 2 to 50 amino acids that can modulate follicular biology through targeted mechanisms.12 Research suggests that peptides can strengthen extracellular matrix (ECM) integrity, stimulate dermal papilla activity, improve microcirculation, and prolong the anagen (growth) phase of the hair cycle.12,13 Clinical data support these mechanisms, demonstrating significant improvements in hair density, thickness, and investigator-assessed outcomes.14 Herein, we summarize the safety and efficacy of peptide-based formulations for hair growth, elucidate underlying mechanisms of action, and identify gaps to guide future trial design and optimize clinical integration.
