It's wise to take any advertisement claim with a grain of salt, and some products invite not just skepticism but downright disbelief. Commercials for hair restoration aids may not actually state they will return your bald pate to a state of hirsute lushness, but they nevertheless get your hopes up toward that end. If any product actually did restore hair, it would be considered a medical breakthrough akin to curing cancer. You wouldn't need an ad to sell it.
Likewise health foods that purport to burn body fat. Common sense says that no "natural" food will do that, but there are plenty of products that imply they do. One of these is the tea beverage called Healthiya. In the TV commercial, actor Teruyuki Kagawa is at his sports club preparing to go for a dip in the pool when he notices the slight paunch on the young man next to him. The young man then notices Kagawa noticing him and quickly sucks in his gut. Kagawa smiles because he has no paunch thanks to the fact that he drinks Healthiya, which, when it arrives in his stomach, sets off a glowing fire that is presumably burning up that oily ramen he had for lunch.
If you automatically doubt the veracity of this implication, at the end of the commercial a symbol depicting a stylized human body with arms stretched toward the sky appears at the bottom of the screen to indicate that Healthiya has been designated by the government as a tokutei hoken-yo shokuhin ("tokuho" for short), or "food for specified health use," so you don't have to worry about whether or not the ad's implication is true or not, because the authorities have already worried for you and concluded that it is.