Raspberry ketones are what give red raspberries their powerful aroma. But despite their name, they've got nothing to do with the ketone bodies your body can make (or the ones you find in exogenous ketone supplements). Still, some people claim that raspberry ketones — mixed with green tea — can help with weight loss by breaking down fat and making cells more susceptible to the fat-burning hormone norepinephrine, among other things. However, there is not a single scientific study that was performed on humans to back up any of those claims. What's more, natural raspberry ketones are incredibly expensive to manufacture, as you need 90 pounds of raspberries for a single dose. As a result, all of the raspberry ketone supplements on the market are synthetic.