20% off Select Protein Powder & Energy Drinks. Prime members only. Amazon has a 12-pack of the C4 Original Sugar Free Sparkling Energy Drink Pre Workout Performance Drink, 16 oz. Cans (Frozen Bombsicle, Midnight Cherry, Purple Frost, Orange Slice or Tropical Blast) for $25 - 20% off coupon (check "Apply coupon" box) - 5% off with Subscribe & Save (cancel anytime) = $19 with free shipping on $25+ or with Prime.