First off, this product comes with a tag offering you free stuff for a 5 star review. So you can know the reviews are kind of skewed. But hey, it's not the first product I've purchased with this kind of offer.
Sadly, it is however, the worst product with this offer.
Flyby does not prevent hangovers. Every time I've taken this product as directed on the label, I have the worst headache I've had in years. I dont feel sick which is good, but the headaches last for days even without drinking. This product does not help, and if anything makes it worse.
The ingredients are good. But not as a supposed hangover preventer. Milk thistle will help your liver, but whatever else is in this is going to guarantee a hangover regardless of quantity drank. Would NOT recommend.