Ketone Supplements: Salts vs. Esters

If you have been on a keto diet to lose weight or used ketosis to improve endurance performance, maintain weight or to enhance brain function, you’ve probably wondered whether you should use a supplement to achieve a state of ketosis.  You’ve also probably been confused about the conflicting information you’ve found online.  If you search keto or ketosis, you will get pages of advertisements for keto salts. 

You can create a state of ketosis on your own by eating a high-fat, low-carbohydrate diet.  But if you’ve tried this diet, you know how hard it is to get into ketosis and how hard it is to maintain the diet and ketosis.  Not to mention “keto flu”, when you are first going into the state of ketosis!

In addition to achieving ketosis with diet alone, there are two other ways to reach some level of ketosis. We will break those down for you here, but first a quick primer on ketosis. 

What is Ketosis?

Ketones are a highly efficient energy source that the body produces naturally during fasting, carbohydrate restriction or after extreme exercise.  Ketone supplements are referred to as the fourth food group after carbohydrate, fat and protein.  Ketosis is generally defined as blood ketone levels greater than 0.5 mM.

How does the body reach Ketosis?

There are two ways to reach ketosis:  

1. Endogenous ketones are naturally produced by the liver from fat when fasting or on a ketogenic diet.  It can take weeks of a strict diet of high-fat, low-carbohydrate foods to reach this state of nutritional ketosis.  However, the high-fat diet required to reach nutritional ketosis can produce negative health effects, especially if carbohydrate intake is increased.  
2. Exogenous ketones are consumed as a supplement that can elevate blood ketone levels within minutes, thereby putting the body immediately into a state of ketosis.

Overview: Ketone Bodies

We produce three ketone bodies: Acetone, Acetoacetate (AcAc) and d-Beta-Hydroxybutyrate (BHB).  Acetone cannot be used for energy production and is removed from the body as a waste product, so is not useful as a supplement.  AcAc is made in the liver and is converted into βHB, but it is also spontaneously broken down into Acetone, which cannot be used for energy production. 

Because BHB is more stable than AcAc and is not converted to Acetone, BHB is mostly used in supplements to achieve a state of ketosis.  However, a large difference in the concentration of blood ketone achieved by a supplement depends on how BHB is bound and delivered.

Exogenous Ketone Supplements: Ketone Salts

Let’s start with probably the most well-known and popular, ketone salts. Ketone salts are widely available on the market, and you will always see BHB on the labeling.  However, the details matter - salts are typically a powder containing BHB bound to a mineral salt (sodium, potassium, magnesium or calcium) or an amino acid (lysine or arginine).  The salts result in low ketone levels, less than 1 mM, because many contain a form of βHB, l-beta-hydroxybutyrate, that is neither detected in, nor metabolised by, the human body.

Although ketone salts are inexpensive, the side effects and health implications are important to understand.  The amount of sodium contained in one serving can be 70% of the recommended daily allowance.  There is no evidence of salts improving endurance performance and some studies report that the excessive salt consumption decreased performance (possibly due to GI issues).  Also to mention are the long-term health implications of chronic high salt consumption linked to hypertension and cardiovascular disease and the unknown effects of ingesting large amounts of non-natural l-beta-hydroxybutyrate.

It is important to note that the FDA does not recognize ketone salts as GRAS (Generally Recognised as Safe).  You need to read the ingredient list very carefully because, unfortunately, the amount of sodium may be hidden in the long list of ingredients in many ketone salt products.

These potential negative effects, combined with limited increase in BHB levels, makes ketone salt products hard to swallow.  

Exogenous Ketone Supplements: Ketone Esters

Ketone esters contain BHB without salts.  Ketone esters are bound to a ketone precursor (like butanediol) via an ester bond.  There are three ester bonds: monoester (one), diester (two), or triester (three).  All esters will raise ketone levels, but monoesters are superior.

One ketone monoester, butanediol-BHB, has been shown in studies to improve human endurance performance, recovery and cognition with few GI side effects.  Most importantly, this monoester safely raises blood ketone levels to around 4 mM within 30 minutes of consumption, which has proved beneficial for endurance performance, recovery, hunger control, blood glucose management and neurodegenerative disease. 

The only ketone monoester on the market was developed at the University of Oxford and the NIH with DARPA funding.  The product, deltaG, manufactured by TdeltaS Global gets you into a state of ketosis faster and safer, being completely bioavailable, than any other product on the market. 

deltaG is salt free, has very few GI issues and is beneficial for endurance performance. 

The downside of ketone esters?  The taste and the cost.  They don’t taste great, but neither do the salts.  Cost – ketone salts are cheap, but the ketosis produced is negligible and the side effects expensive.  The deltaG ketone ester is expensive to manufacture but provides many benefits without the negative side effects of salts.  It is also GRAS certified, unlike ketone salts.