Beta-alanine has a higher bioavailability (better absorption) than carnosine. When we ingest carnosine directly, it’s broken down by digestive enzymes into its constituent amino acids — beta-alanine and L-histidine — before it reaches skeletal muscles,[1] making oral carnosine supplementation an ineffective method for elevating muscle carnosine levels in humans.[2] Supplementing with beta-alanine bypasses this degradation process and may ensure that a greater amount of the amino acid is transported from the bloodstream to the skeletal muscle, where it can combine with L-histidine to produce carnosine.
In addition, beta-alanine is less expensive than carnosine — because beta-alanine is just as if not more effective for elevating muscle carnosine stores, it’s also the more financially sound option for supplementation.