Visitors to Paris are often curious about the number of pharmacies they see throughout the city. The bright green crosses that are lit to indicate an open pharmacy seem to decorate every city block, serving as beacons that promise remedies to the tired, the ill and those with skin in need of improvement. But despite that France has the largest number of filled prescriptions per capita in the entire EU, this is not just a country of hypochondriacs; pharmacies happen to be every parisienne’s first stop for cosmetic...