You may have heard of the two terms "AKG" and "Ca-AKG". They appear quite similar, yet many people confuse them for the same substance, while they are actually two distinct compounds.
AKG, the full name of which is Alpha-Ketoglutaric Acid, is a natural intermediate of the TCA cycle, the core pathway for human energy metabolism. In other words, your cells produce and consume it every single day.
AKG (Alpha-Ketoglutaric Acid) exists in free acid form with high acidity. It is an intermediate metabolite of the tricarboxylic acid cycle (TCA cycle), the core pathway of human cellular energy metabolism. Simply put, human cells synthesize and utilize this compound daily.
Ca-AKG stands for Calcium Alpha-Ketoglutarate. It is a calcium salt formed by combining AKG with calcium ions, featuring superior stability and lower acidity.
In China, AKG is explicitly listed in GB 2760-2024, the National Food Safety Standard for Uses of Food Additives. Under this national standard, it is categorized as a synthetic food flavoring, permitted for appropriate use according to production demands. As the calcium salt of AKG, Ca-AKG complies with the same regulatory requirements as AKG.
In the United States, AKG is included in the industry-recognized Old Dietary Ingredients (ODI) list, which covers dietary ingredients already available on the market prior to the implementation of the DSHEA Act on October 15, 1994. This status allows AKG to be directly used as a dietary supplement ingredient without filing a New Dietary Ingredient (NDI) notification with the FDA.
For Ca-AKG, Self-GRAS (Self-affirmed Generally Recognized As Safe) certification is currently the primary compliant channel for its sale as a raw material for dietary supplements in the U.S. market. On January 7, 2026, AKG and Ca-AKG products from Shenzhen Xintianhe Biotechnology successfully passed the scientific evaluation for U.S. Self-GRAS certification.
Free acid AKG has strong acidity and is mostly applied in food flavor formulation, fermentation raw materials and nutrient-fortified powders. As a calcium salt, Ca-AKG is mild, stable and low in irritation, with broader application prospects. It can be processed into various formulations including solid beverages, compressed candies, dietary capsules and oral liquids, widely used in sports nutrition, anti-aging dietary supplements for middle-aged and elderly people, functional foods, as well as nutritional feed additives.
AKG and Ca-AKG differ in chemical properties and applicable regulations. Please make clear distinctions when selecting raw materials.
