Radiofrequency microneedling (RFM) combined with biostimulators (such as poly-L-lactic acid [PLLA], calcium hydroxylapatite [CaHA], or polynucleotides) is supported by emerging clinical evidence for enhanced skin tightening and collagen stimulation. RFM induces controlled thermal injury in the dermis, leading to neocollagenesis, elastogenesis, and extracellular matrix remodeling, as demonstrated by histological and molecular studies showing increased collagen I/III ratios, fibroblast activation, and upregulation of growth factors such as TGF-β and EGF. Clinical trials and reviews confirm improvements in skin elasticity, density, and thickness, with sustained effects for at least six months post-treatment.

Combination therapy with biostimulators further augments these effects. A recent scoping review highlights that integrating RFM with agents like PLLA, polynucleotides, and platelet-rich plasma enhances collagen synthesis and skin repair beyond monotherapy, with both subjective and objective outcome measures supporting efficacy and safety. Systematic review data indicate that combining biostimulators with energy-based devices (including RFM) yields superior improvements in skin texture, elasticity, and contouring, though protocols and outcome measures remain heterogeneous.Adverse events are generally mild and transient, such as erythema and bruising, with rare severe complications. 

In summary, the medical literature supports the synergistic use of radiofrequency microneedling and biostimulator combination therapy for skin tightening and collagen stimulation, with evidence of enhanced clinical and histological outcomes compared to monotherapy.