Supplementing with BHB (exogenous ketones) can help amplify your keto diet results. 
 
What is BHB?
Beta-Hydroxybutyrate (BHB) is a ketone body produced by the liver, from fat, for energy when glucose isn’t available. It ultimately becomes the body and brain’s primary source of energy.  Since the liver naturally produces BHB during ketosis, the process can take quite some time, often resulting in symptoms of fatigue, hunger (cravings for sugar, a faster energy source), and mental cloudiness.  That’s why supplementing BHB on a keto diet can have a profound positive impact.
 
What are the benefits of taking BHB?
BHB easily crosses the blood-brain barrier resulting in easily accessible energy to the brain and muscle tissues, becoming a source of energy after entering the mitochondria, being converted to Acetyl-CoA, and then ATP through the Krebs cycle (the same process that glucose goes through to become ATP).  This ultimately results in many direct benefits, including:
Reducing feelings of hunger
Improving mental performance
Increasing physical performance
Longer lasting energy
Decreasing the amount of time, it takes for your body to enter ketosis
Helping reduce the “low-carb flu” symptoms
 
When should you take BHB?
You can really take BHB anytime, but it’s best to avoid taking it with meals since that’s when you’ll already be supplying your body with energy. Why waste a serving, right? Here’s how BHB can work in your meal plan:
First thing in the morning (in place of breakfast) to help keep your ketones up.
In between meals to kill cravings and energy crashes.
Before/during workouts to supplement with readily available energy.