A topical scalp treatment combining Centella asiatica–derived extracellular vesicles (EVs) with recombinant long-acting growth factors significantly improved hair growth and scalp health in a 56-day randomized controlled trial, according to a preprint published on medRxiv.
The double-blind study enrolled 60 adults aged 18 to 60 and randomly assigned them to one of five groups: a placebo control; a base formulation containing 0.1% caffeine and panthenol; the base formula plus recombinant growth factors; the base formula plus C asiatica EVs; and a complete formulation incorporating all active components. Participants applied approximately 1 mL of their assigned product once daily over the study period.
Patients receiving the complete formulation showed the most pronounced benefits across all measured outcomes. By day 56, mean hair shaft thickness increased by 28 micrometers, compared with a 14-micrometer gain in the placebo group. Hair density rose 24% from baseline in the active treatment group, double the increase observed with placebo. Cumulative hair length growth reached 3.5 centimeters, with statistically significant differences emerging as early as day 14.
The combination therapy also delivered notable scalp health improvements. Sebum levels fell by 59% from baseline in the complete formulation group, outperforming both the placebo and base formulation. Hair loss, assessed via standardized combing tests, declined by 64% in the active group versus 43% in the placebo arm by the end of the trial.
Researchers used standardized and validated measurement tools, including the Courage-Khazaka MPA580 system with a Sebumeter SM815 probe for sebum analysis and the ScalpX Intelligent Scalp Diagnostic System with high-resolution digital microscopy for hair morphometry. All assessments were conducted under controlled environmental conditions at HungKuang University in Taichung City, Taiwan.
The investigational product featured Fc-fusion–modified recombinant insulin-like growth factor-1 (rIGF-1) and fibroblast growth factor-7 (rFGF-7), engineered for prolonged biological activity, alongside EVs derived from Centella asiatica leaf, petiole, and callus tissues. Randomization was performed using a block design with sealed, opaque envelopes, and all enrolled participants completed the study without major protocol deviations.
Study participants were predominantly female, with a mean age of 36 years, and baseline characteristics were comparable across all groups. Statistical analyses included repeated-measures ANOVA for within-group changes and one-way ANOVA for between-group comparisons.
The authors noted several limitations, including the short study duration relative to full hair follicle cycling, modest improvements observed in the placebo group, and limited generalizability due to the young, largely female cohort. The sample size also restricted more detailed subgroup analyses.
In their discussion, the investigators highlighted the need for alternative hair loss therapies with improved tolerability. While minoxidil and finasteride remain standard treatments, they noted that side effects and rebound shedding can undermine long-term adherence. The authors suggested that combining growth factors with plant-derived EVs could offer a multi-targeted approach to scalp care.
The research was led by HungKuang University’s Department of Applied Cosmetology in collaboration with academic partners in Taiwan, Japan, and the United States. The trial was registered on ClinicalTrials.gov (NCT06985121). Schweitzer Biotech Company provided funding and study materials but reported no involvement in study conduct or data analysis, though several authors disclosed professional ties to the company.
The findings have not yet undergone peer review. According to the authors, the study represents the first human clinical trial to evaluate a combined formulation of plant-derived extracellular vesicles and growth factors for scalp and hair growth applications.
