Polynucleotides (PN) are highly purified DNA fragments from salmonid fish (rainbow trout) tissue, 95% identical to human DNA. Injected intradermally, they activate adenosine A2A receptors, stimulate fibroblasts and the synthesis of collagen and elastin, improve microcirculation and reduce inflammation. The result is denser, hydrated, more even skin with a long-lasting regenerative effect — not just a short-term increase in volume.