Melanotan-2 (MT-2) and GHK-Cu are peptides used in skin research, often explored together for synergistic effects: MT-2 stimulates melanin for tanning and UV protection, while GHK-Cu promotes collagen, wound healing, and anti-aging by supporting dermal repair and elasticity, essentially combining pigmentation control with overall skin regeneration, though they function differently, with MT-2 targeting melanocortin receptors for pigment and GHK-Cu modulating tissue remodeling.