Lord knows what 's in it - the stuff smells like falling into a chemical factory - .
It 's the only all - day , waterproof suncream we know that actually works and this is after tests everywhere from the UTMB to the Marathon des Sables .
Lord knows what 's in it - the stuff smells like falling into a chemical factory - but it 's the only all - day , waterproof suncream we know that actually works and this is after tests everywhere from the UTMB to the Marathon des Sables .