New Long COVID Clinical Trial Shows Oxaloacetate CFS Significantly Improves Cognitive Function and Reduces Symptom Burden in Long COVID Patients

August 2025 — SAN DIEGO, CA — A new randomized, double-blinded, controlled clinical trial published in Frontiers in Neuroscience reveals promising results for Oxaloacetate CFS, a medical food for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Long COVID that has progressed to ME/CFS. The study, titled “REGAIN: A Randomized Controlled Clinical Trial of Oxaloacetate for Improving the Symptoms of Long COVID,” found that Oxaloacetate CFS produced statistically significant improvements in cognitive performance (Brain Fog) and reduced overall symptom burden among patients suffering from Long COVID.

Over the course of the 6-week trial, participants taking Oxaloacetate CFS experienced:

• Significant improvements in cognitive function, including faster reaction times, increased cognitive efficiency, and improved accuracy in tasks requiring focus and decision-making.
  

• Significant reductions in symptom burden, as measured by the DePaul Symptom Questionnaire–Short Form (DSQ‑SF), with benefits emerging as early as Day 21 of Oxaloacetate therapy.

“These findings are an exciting step forward in the search for effective relief for Long COVID patients,” said Oxaloacetate CFS Chief Science Officer Alan Cash. “The type of cognitive performance improvements seen in this study can be life-changing after years of Long COVID’s infamously debilitating brain fog. These improvements can mean the ability to resume work, to live more independently and to regain a sense of dignity and a love of life again.” 

The cognitive gains seen in the trial were strongly correlated with improvements in symptom burden, suggesting a powerful connection between neurological support and overall recovery in post-viral syndromes like Long COVID. The trial also confirmed that Oxaloacetate CFS was well-tolerated, with a safety profile comparable to the control group.

Oxaloacetate CFS is a medical food that delivers a large dose of Anhydrous Enol-Oxaloacetate (AEO).  Oxaloacetate is a natural human metabolite involved in mitochondrial energy production. Prior studies have explored the potential of Oxaloacetate CFS in addressing symptoms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), finding significant improvements in cognitive function, an a physical fatigue reduction of up to 63% in enhanced responders.  

As a designated medical food, use of Oxaloacetate CFS requires the supervision of a licensed healthcare provider to help set dosing levels.

The full clinical trial data is available here.