Topical Caffeine is used for vascular-looking puffiness and surface tightness, not because skin needs energy.
The lazy explanation is that Caffeine wakes up tired skin. That sounds cute, but it is not the useful mechanism. Topically, Caffeine is mainly interesting because it can support vasoconstriction, meaning the look of surface blood vessels tightening. Around the eye area, that can make puffiness and vascular-looking darkness appear softer.
That is why Caffeine is common in eye formulas. If the dark circle is brown pigment, Caffeine is not the main answer. If the dark circle is blue, purple or shadowy from vascular show-through and puffiness, Caffeine makes more sense. It is not the whole eye formula. It is one part of it.
Helloskin uses Caffeine in Illuminate V.2 and Revive V.2 because those formulas already carry peptide complexes for texture and firmness support. Caffeine brings the surface-level puffiness angle. In the hair serum, it sits beside AHK-Cu and GHK-Cu as scalp-environment support.
Caffeine is not the hero of every eye concern. It is brilliant when puffiness is part of the picture.
