Context: Hair loss (alopecia) presents both aesthetic and psychological challenges, significantly impacting quality of life. Platelet-rich plasma (PRP) therapy has gained prominence due to its ability to deliver growth factors and modulate local inflammation. However, uncertainties remain regarding the mechanisms through which systemic inflammation, oxidative stress, and coagulation factors influence PRP’s efficacy. Objectives: This narrative review explores the impact of inflammatory biomarkers (e.g., NLR, PLR, IL-6, TNF-α) and growth factors (VEGF, TGF-β, FGF) on hair regeneration in PRP therapy. It discusses how oxidative stress and vitamin status (B12, D, folate) correlate with therapeutic success. Additionally, it examines the PRP preparation protocols and combined approaches (microneedling, minoxidil, LLLT) that may amplify clinical responses. Results: The synthesized data highlight that elevated systemic inflammation (increased NLR/PLR values) can limit PRP’s effectiveness, while the regulation of inflammation and optimization of antioxidant status can enhance hair density and thickness. Integrating vitamins and an anti-inflammatory diet into the therapeutic protocol is associated with more stable hair growth and reduced adverse reactions. The variability in PRP’s preparation and activation methods remains a major obstacle, underscoring the need for standardization. Conclusions: Integrating inflammatory biomarkers with oxidative stress indicators provides fresh insights for tailoring PRP therapies in alopecia. Multimodal treatment strategies combined with collaborative multicenter studies—in which biological markers are embedded within rigorous protocols—could establish standardized methodologies and significantly enhance the treatment success.

Background/Objectives: Platelet-rich plasma (PRP)–based regimens are widely used in non-scarring alopecia, yet objective response is variable and clinic-ready predictors are lacking. We evaluated short-term trichoscopic outcomes in routine practice and tested whether baseline complete blood count–derived inflammatory status, quantified by the neutrophil-to-lymphocyte ratio (NLR), can stratify response under PRP-based therapy. Methods: We performed an ambispective observational cohort study (October 2024–October 2025) in an outpatient dermatology practice. The final analytic cohort included 129 patients allocated to four treatment groups: PRP alone (n = 54), PRP combined with microneedling-assisted Purasomes Hair & Scalp Complex (HCS50+, Dermoaroma; exosome-containing) (n = 33), PRP combined with microneedling-assisted Mesoaroma Hair Cocktail (scalp formulation; nutrient complex) (n = 24), and a nutrient complex alone (n = 18). Trichoscopy (FotoFinder ATBM; FotoFinder Systems GmbH, Bad Birnbach, Germany) was obtained at baseline (T1) and first follow-up (T2). Density response was defined as a ≥10% increase in total hair density and hair-cycle response as an anagen fraction increase ≥5 percentage points. Predictive analyses were prespecified and restricted to PRP-containing regimens, using logistic regression and a multilayer perceptron with repeated cross-validation for internal validation. Results: Across the full cohort (n = 129), total hair density and hair-cycle parameters improved from T1 to T2. In the PRP-containing subgroup (n = 111), baseline NLR strongly discriminated density responders (AUC 0.85, bootstrap 95% CI 0.77–0.91). In multivariable models, NLR remained independently associated with density response (OR 0.31 per 1-unit increase, 95% CI 0.20–0.48). Conclusions: In this cohort, baseline NLR was associated with discrimination of early trichoscopic response in PRP-based treatment of non-scarring alopecia. Using the Youden-derived cut-off (NLR = 2.202), patients with NLR > 2.202 had a higher risk of density non-response (72.1% vs. 4.7%), corresponding to a 15.49-fold increased failure risk in this cohort. These findings are exploratory and hypothesis-generating, and external validation and calibration are required before any routine clinical or decision-support use.