Tracked by Evreward since 2011, Myprotein offers coupons, cash back rebates and rewards, with savings as high as 90% off. Myprotein discount coupons are plentiful, usually available every month, and are often more valuable than similar merchants. Even when Myprotein doesn't have a coupon, you can always get up to 20% cash back, and other great rewards, with every purchase.