Do ProLon® 5-day Menus 1 and 2 contain nickel? 29 June 2022 15:02 Yes, both menus include components that may contain nickel. Related articles Can I do two consecutive ProLon® 5-day cycles? Can I consume the foods contained in the ProLon® 5-day kit every other day? Do I lose weight? Can I do ProLon® 5-day if I have COVID-19 (even in the case of asymptomatic subjects)? How many times can I repeat ProLon® 5-day?