Acute estradiol and progesterone therapy in hospitalized adults to reduce COVID-19 severity: a randomized control trial

COVID-19 outcomes are less severe in women than men suggesting that female sex is protective. The steroids estradiol (E2) and progesterone (P4) promote anti-inflammatory immune responses and their therapeutic use for COVID-19 has been under investigation. The aim of the study was to evaluate the efficacy of a short systemic E2 and P4 combination in mitigating COVID-19 severity in hospitalized men and women. In a phase 2, single center, double blind, randomized placebo-controlled trial, ten male and female participants hospitalized for COVID-19 with scores 3-5 on the 9-point WHO ordinal scale were randomized to receive either (1) E2 cypionate (5 mg, IM) and micronized P4 (200 mg, PO), or (2) placebo-equivalent, in addition to standard of care (SOC). The primary outcome was the proportion of patients whose WHO scores improved to 1-2 on the day of discharge. Secondary outcomes included length of hospital stay (LOS), days on oxygen therapy (DOT), readmission rates (RR), adverse events (AEs), and change in circulating biomarkers using untargeted proteomics and cytokine profiling. There were no significant changes between the groups in primary outcome, LOS, DOT, RR or AEs. The E2P4 group exhibited a decrease in biomarker pathways of respiratory and gastrointestinal disease inflammation, infection by coronavirus, and immune cell trafficking and inflammatory response. A short-term E2P4 treatment in patients hospitalized for COVID-19 decreases biomarkers of inflammation. Considering the availability, low cost, and safety of E2 and P4, our results warrant additional studies to explore their effects in mitigating other viral pandemics. Clinical Trial Registration NCT04865029, ClinicalTrials.gov; (First trial registration 29/04/2021).