Ah, the eminent Dr. Oz! If he says it, generally, I take it as gospel.
Seriously, though, it’s not total bunk. A study in rodents found that raspberry ketone supplementation both prevented fat gain on a proven obesogenic diet and helped already fattened rats slim down a bit. Sounds good, right? I mean, sure, we’re not big hairless, tailless rats, but we’re both mammals, and we can glean a lot of hints about our own physiology by studying rodents. Eh, not so fast: the rodents’ diets were up to 2% raspberry ketones. Yes, it wasn’t quite a supplement, it was a sizable component of their diets. That would be like if you swapped out polyunsaturated fat for resveratrol. When you’re measuring a supplement in calories, rather than micrograms, milligrams, or IU, I think it’s time to step away and reevaluate your relationship with the compound.
I suppose you could replicate the rat dosage and get 2% of your calories from raspberry ketones and hope for a result, but that would get pretty expensive really fast. The typical bottle has 60 capsules with anywhere from 100 to 500 mg per capsule, and you’d be taking at least half the bottle a day to hit the heroic dosages. Good luck