Argireline (acetyl‑hexapeptide‑3) applied to the skin of aged mice twice a day for six weeks improved the skin’s microscopic structure: more sturdy type I collagen and less type III collagen, which together suggest a tighter, younger‑looking skin. The study supports the idea that this peptide can help reduce wrinkles, echoing earlier human trials that reported safety and wrinkle‑reduction benefits.

Argireline, a synthetic peptide, which is patterned from the N-terminal end of the protein SNAP-25, can both reduce the degree of existing facial wrinkles and demonstrate effectively against their development. In our past studies, we found out that Argireline had a significant anti-wrinkle effect in Chinese subjects and that it was safe and well tolerated. To observe the effect of Argireline on histological changes in the skin in the aged mice induced by D-galactose. Argireline was applied to the aged mice twice daily for 6 weeks. The histological changes in skin tissue were evaluated using hematoxylin-eosin (HE) and picrosirius-polarization (PSP) stains. The amount of type I and of type III collagen fibers were also semi-quantitatively compared using software Image-ProPlus. There was an improvement in the histological structure of skin tissue in the aged mice; the amount of type I collagen fibers increased (P < 0.01), while that of type III collagen fibers decreased (P < 0.05). This study revealed that Argireline could improve the histological structure of skin tissue and rejuvenate the aging skin.