I urge everyone to bookmark that blog; it is always a fascinating tour of the weirder and wonderfuller places on our planet. And let me leave you with this simply jaw-dropping video of undulatus asperatus in action.
(A sunscreen with a physical block like titanium dioxide or zinc oxide can be applied last, after a serum or moisturizer.) Apply a serum next and, finally, moisturizer if you need it. Polis also recommends serums or sunscreens with moisturizers built in because they save time.
A topical vitamin C serum is an oil-and-water-based cosmetic product that delivers concentrated vitamin C. Vitamin C serums, whether from the drugstore or a high-end department store, offer two major advantages over moisturizers: rapid absorption and deep penetration.