But getting into and staying in ketosis can be hard work. Maybe high-fat foods don’t work well for you. Perhaps you travel a lot or otherwise find maintaining keto difficult. Or you’re an athlete who wants to eat carbs on training days. Shifting from glucose to ketones as your dominant fuel could take days or weeks, and sustaining it can be equally challenging. “Maintaining ketosis can be difficult, as consumption of even a small quantity of carbohydrates or excess protein can rapidly inhibit ketogenesis,” researchers have noted. That’s where exogenous ketones come in. These supplements promise to sidestep the tediousness of rigorously sticking with a high-fat diet. But do they work? Let’s look at the science. Supposedly, even if you consume exogenous ketones with carbohydrates, your body will preferentially use ketones first. They come in two forms: salts and esters. Salts are bound to minerals and come in a powder form that you mix with liquid. The latter form is linked to a compound called an ester and comes as a liquid. While they differ in certain ways, both forms promise to get your body into ketosis fast—like 30 minutes fast. One animal study found exogenous ketone drinks could raise ketone levels without restricting carbs. In the study, rats that got exogenous ketones gained significantly less weight compared with those who did not get them. Human studies show similar results. One review of three studies that gave participants a ketone ester or salts found that both forms elevated blood ketone levels for hours. Researchers concluded that “exogenous ketone drinks are a practical, efficacious way to achieve ketosis1. Some reasons to include them in your plan might be: A cutting-edge nutrition deep dive taught by 20+ top health & wellness experts
