Myprotein offers the Myprotein Impact Whey Protein 5.5-lb. Bag in several flavors for $51.99. Add two to your cart and apply coupon code "FLASH49" to cut it to $49.86. With $4.99 for shipping, that's the lowest price we could find for this quantity by $57, although we saw this quantity for $4 less last week. Each serving contains 21g of protein.