I have seen a couple of brands like sergeants introduce new products in the last few months, and for the most part, these products do not work. However, Frontline seems to have lost the patent they’ve had for years, and now these other brands can make a product with the exact same ingredients as frontline. I have tried “pet armor”- which is Walmart’s brand, and I have seen a similar product at Publix(and it might have been sergeants). Look at the boxes, and see which brand has the same contents in the same amount as frontline, and whatever brand name it is under doesn’t matter. I have used the Pet Armor on Lillie, who has severe flea bite dermatitis, and my boss(that has 3 dogs) used it as well, and it works exactly as well as frontline, but instead of $50 a box, we paid $28+tax.