Bluemercury and Macy's launched a Flex partnership making 2,300+ products eligible for HSA/FSA spending online — across La Mer, SkinCeuticals, EltaMD, Therabody. The quiet shift: if treatment skin, SPF, acne and eczema-adjacent products can tap tax-advantaged health accounts, growth will start being decided by medically legible shopping missions, not TikTok.