This study will compare the effects of AXA1125, an orally active mixture of amino acids, compared to placebo, on improving muscle function (metabolism) following moderate exercise in subjects with fatigue-Predominant Post-Acute Sequelae of SARS-CoV-2 as well as the safety and tolerability of AXA1125. Subjects will take one dose of AXA1125 or a placebo twice daily for 28 days.

Inclusion Criteria:

• Willing to participate in the study and provide written informed consent
• Male and female adults aged > 18 years and less than 65 years
• Must have had clinically suspected COVID-19 and a positive antibody test or a documented SARS-CoV-2 infection (a positive reverse transcription polymerase chain reaction test) at least 12 weeks prior to Screening
• Must have fatigue-predominant PASC
• Other than PASC, a subject must be in good health without other significant medical or not well controlled medical or psychiatric conditions

Exclusion Criteria:

• Other than PASC, have an explanation for fatigue
• Other than PASC, a history or presence of an uncontrolled, clinically significant disease
• Medical history that includes of Non-invasive or invasive ventilatory support for COVID 19, Intensive care unit or other high dependency unit admission for COVID-19, Hospitalization for >1 week for COVID-19 without intubation