On the skin
Ginkgo biloba and ginseng have long been associated with stimulating blood flow. Applied topically, they act where they are put, which is why the effect arrives quickly and does not last past the night.
Ginkgo · Ginseng→local circulation→same night
Through the bloodstream
L-arginine is a precursor to nitric oxide, a molecule that dilates blood vessels and may improve blood flow. Zinc, selenium and taurine support the same pathway. Nothing here works on the first evening.
L-arginine→nitric oxide→vessel dilation