The review analysed 19 clinical studies involving 624 participants. Twenty-one per cent investigated EVs, including exosome formulations, while 79 per cent examined cell-free conditioned media derived from cultured stem or blood cells. Across studies, mean participant age was about 49 years, and women comprised more than 80 per cent of subjects.  

Statistically significant improvements were reported in multiple skin parameters: a 27 per cent rise in elasticity (p < 0.05), more than 20 per cent increase in hydration (p < 0.05), and over 10 per cent reduction in wrinkle depth (p < 0.05). Some formulations also reduced melanin levels by roughly 10 per cent after eight weeks, with stronger effects in younger participants.  

Most of the formulations reviewed were human-derived, including those from adipose tissue, umbilical cord, amniotic membrane and blood-cell secretome sources, though some used non-human biologics such as Lactobacillus plantarum or bovine milk exosomes. No serious adverse events were reported, with side effects limited to temporary redness or mild swelling, especially when used with microneedling.  

The authors, from Iran University of Medical Sciences, concluded that EV- and CM-based therapies are emerging as promising non-invasive options for aesthetic and regenerative dermatology but warned that variations in cell source and preparation make direct comparisons difficult. Standardised manufacturing and clear regulatory frameworks are required before routine clinical adoption.  

It should be noted that human-derived exosomes are not authorised for cosmetic or therapeutic use in the UK, where the Medicines and Healthcare products Regulatory Agency (MHRA) classifies them as unlicensed medicinal products.