Study findings updated . AI-assisted evidence summary, not individual medical advice or a clinician endorsement.
THE SHORT VERSION
What’s worth knowing.
The key findings, what they mean, and the context that matters.
THE HEADLINE TAKEAWAY12.3 points fewer deathsPercentage-point drop in 28-day deaths among ventilated patients on dexamethasone
Dexamethasone, a steroid, cut deaths among the sickest COVID patients.
In a UK trial of patients hospitalized with COVID, those given dexamethasone, a steroid that tamps down inflammation, were less likely to die within 28 days than those on usual care. On breathing machines, 29.3% died with it vs 41.4% without. Patients on oxygen also benefited, but those needing no oxygen did not (17.8% vs 14.0%).
It showed that calming the body's own immune overreaction, not just attacking the virus, can save lives in severe COVID, and that the benefit depends on how sick a patient is when treatment starts. An open-label trial (doctors knew who got the drug) run in spring 2020, before vaccines or the Omicron variant.
See the evidence
A randomized trial (RECOVERY) of 6425 hospitalized patients in the UK, March to June 2020, comparing dexamethasone with usual care.
From the study: “The age-adjusted absolute reductions in 28-day mortality associated with the use of dexamethasone were 12.3 percentage points”
12.3 points fewer deaths
RECOVERY Collaborative Group et al. Dexamethasone in Hospitalized Patients with Covid-19. The New England journal of medicine. 2021.
From the study: “In the dexamethasone group, the incidence of death was lower than that in the usual care group among patients receiving invasive mechanical ventilation (29.3% vs. 41.4%”
12.3 points fewer deaths
RECOVERY Collaborative Group et al. Dexamethasone in Hospitalized Patients with Covid-19. The New England journal of medicine. 2021.
Paxlovid did not lower hospitalizations or deaths in vaccinated higher-risk adults.
0.8% hospitalizedor died on Paxlovid, vs 0.7% with usual care, in mostly vaccinated UK adults
In UK and Canadian trials of mostly vaccinated adults aged 50 or older or with health conditions, adding Paxlovid (nirmatrelvir-ritonavir) to usual care did not lower the already low rate of hospitalization or death: 0.8% with the pill vs 0.7% without in the UK trial. People on the pill did report recovering sooner: 33.0% vs 22.1% had early lasting recovery.
Serious outcomes are now rare in people with vaccine or infection immunity, so this pill's measurable payoff in these trials was feeling better sooner, not fewer hospital stays. Open-label (people knew if they got the pill), so recovery reports may be biased; an earlier trial in unvaccinated people found 0.8% vs 6.3% hospitalized or died.
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Two open-label randomized trials, PANORAMIC in the UK (3516 people) and CanTreatCOVID in Canada (716), enrolling community adults from 2021 to 2024.
From the study: “In the PANORAMIC trial, 14 of 1698 participants (0.8%) in the nirmatrelvir-ritonavir group and 11 of 1673 participants (0.7%) in the usual-care group were hospitalized or died”
0.8% hospitalized
Butler CC et al. Oral Nirmatrelvir-Ritonavir for Covid-19 in Higher-Risk Outpatients. The New England journal of medicine. 2026.
From the study: “nirmatrelvir-ritonavir did not reduce the incidence of hospitalization or death among vaccinated higher-risk participants with SARS-CoV-2 infection”
0.8% hospitalized
Butler CC et al. Oral Nirmatrelvir-Ritonavir for Covid-19 in Higher-Risk Outpatients. The New England journal of medicine. 2026.
Ivermectin did not keep high-risk COVID patients out of the hospital.
14.7% on ivermectinwere hospitalized or held in the ER, vs 16.3% on placebo, a gap within chance
In a trial in Brazil of adults with early COVID and at least one risk factor, those given ivermectin for 3 days were about as likely to be hospitalized or kept in the emergency room more than 6 hours as those given a dummy pill: 14.7% vs 16.3%, a gap that could be chance. Starting within 3 days of symptoms showed no benefit either.
Ivermectin, an antiparasite drug, was widely promoted for COVID. This trial gave a relatively high dose and recorded more events than all the trials in earlier pooled analyses combined. A single trial in Brazil, mostly in people of mixed race; it tested treatment of early illness, not prevention.
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A double-blind, placebo-controlled trial (TOGETHER) of 1358 high-risk adult outpatients recruited from 12 public health clinics in Brazil.
From the study: “Overall, 100 patients (14.7%) in the ivermectin group had a primary-outcome event, as compared with 111 (16.3%) in the placebo group”
14.7% on ivermectin
Reis G et al. Effect of Early Treatment with Ivermectin among Patients with Covid-19. The New England journal of medicine. 2022.
From the study: “We observed no benefit with ivermectin as compared with placebo among patients who began the trial regimen within 3 days after symptom onset”
14.7% on ivermectin
Reis G et al. Effect of Early Treatment with Ivermectin among Patients with Covid-19. The New England journal of medicine. 2022.
An antiviral pill cut COVID cases among exposed household members.
2.9% caught COVIDamong household contacts given ensitrelvir, vs 9.0% given placebo
In a trial of people who lived with someone newly sick with COVID and who tested negative themselves, those who took ensitrelvir, an antiviral pill, for 5 days starting within 72 hours of the sick person's first symptoms were less likely to get COVID: 2.9% vs 9.0% on a dummy pill. Side effects were similar (15.1% vs 15.5%).
Until this trial, no antiviral had been approved to protect household contacts after exposure. Ensitrelvir is already approved in Japan to treat COVID; this is evidence it can also prevent it. Funded by the drug's maker, and the illnesses involved were mostly mild: no one in either group was hospitalized for COVID or died.
See the evidence
A double-blind, placebo-controlled trial (SCORPIO-PEP) of household contacts who tested negative: 1030 got ensitrelvir and 1011 got placebo.
From the study: “The incidence of Covid-19 was lower in the ensitrelvir group than in the placebo group (2.9% vs. 9.0%; risk ratio, 0.33”
2.9% caught COVID
Hayden FG et al. Ensitrelvir for Covid-19 Postexposure Prophylaxis in Household Contacts. The New England journal of medicine. 2026.
From the study: “Ensitrelvir administered to household contacts of a patient with Covid-19 within 72 hours after symptom onset in the index patient was effective in preventing Covid-19 in the contacts.”
2.9% caught COVID
Hayden FG et al. Ensitrelvir for Covid-19 Postexposure Prophylaxis in Household Contacts. The New England journal of medicine. 2026.
From the study: “The incidence of adverse events during the trial was similar in the two groups (15.1% in the ensitrelvir group and 15.5% in the placebo group)”
2.9% caught COVID
Hayden FG et al. Ensitrelvir for Covid-19 Postexposure Prophylaxis in Household Contacts. The New England journal of medicine. 2026.
1 in 25 patientsmore left the hospital alive without heart or lung life support on full-dose heparin
In patients hospitalized with COVID but not in intensive care, those given full, treatment-strength doses of the blood thinner heparin were 4.0 percentage points more likely to leave the hospital alive without needing heart or lung life support than those on the usual low preventive dose. Major bleeding was more common: 1.9% vs 0.9%.
Blood clots may worsen COVID. Stronger anticoagulation (blood thinning) improved outcomes in moderately ill patients, but a companion trial found the same strategy did not help those already in intensive care. Open-label (everyone knew the dose) and enrolled April 2020 to January 2021, before vaccines were widely available.
See the evidence
Three linked international randomized trials (ATTACC, ACTIV-4a, REMAP-CAP) analyzing 2219 hospitalized patients not in intensive care, about half in the US.
From the study: “The adjusted absolute between-group difference in survival until hospital discharge without organ support favoring therapeutic-dose anticoagulation was 4.0 percentage points”
1 in 25 patients
ATTACC Investigators et al. Therapeutic Anticoagulation with Heparin in Noncritically Ill Patients with Covid-19. The New England journal of medicine. 2021.
From the study: “Major bleeding occurred in 1.9% of the patients receiving therapeutic-dose anticoagulation and in 0.9% of those receiving thromboprophylaxis.”
1 in 25 patients
ATTACC Investigators et al. Therapeutic Anticoagulation with Heparin in Noncritically Ill Patients with Covid-19. The New England journal of medicine. 2021.
From the study: “In noncritically ill patients with Covid-19, an initial strategy of therapeutic-dose anticoagulation with heparin increased the probability of survival to hospital discharge”
1 in 25 patients
ATTACC Investigators et al. Therapeutic Anticoagulation with Heparin in Noncritically Ill Patients with Covid-19. The New England journal of medicine. 2021.
Metformin taken during COVID was linked to fewer long COVID diagnoses.
41% fewer long COVIDdiagnoses by day 300 in adults given metformin early in COVID, vs placebo
In a US trial of adults with overweight or obesity who had just caught COVID, those given metformin, a low-cost, widely used pill best known for diabetes, were less likely to be diagnosed with long COVID by day 300 than those given a dummy pill: 6.3% vs 10.4%. Ivermectin and fluvoxamine, tested in the same trial, showed no effect.
It is rare randomized evidence that a drug taken during the infection may lower the chance of long COVID, a condition that still lacks proven treatments. Long COVID was a secondary goal, based on participants reporting a doctor's diagnosis; a later, larger trial in lower-risk, mostly immune adults found a weaker, less certain effect.
See the evidence
A quadruple-blind randomized trial (COVID-OUT) of 1126 adults aged 30 to 85 with overweight or obesity, run remotely from six US sites, December 2020 to January 2022.
From the study: “Outpatient treatment with metformin reduced long COVID incidence by about 41%, with an absolute reduction of 4·1%, compared with placebo.”
41% fewer long COVID
Bramante CT et al. Outpatient treatment of COVID-19 and incidence of post-COVID-19 condition over 10 months (COVID-OUT): a multicentre, randomised, quadruple-blind, parallel-group, phase 3 trial. The Lancet. Infectious diseases. 2023.
From the study: “The cumulative incidence of long COVID by day 300 was 6·3% (95% CI 4·2-8·2) in participants who received metformin and 10·4% (7·8-12·9) in those who received identical metformin placebo”
41% fewer long COVID
Bramante CT et al. Outpatient treatment of COVID-19 and incidence of post-COVID-19 condition over 10 months (COVID-OUT): a multicentre, randomised, quadruple-blind, parallel-group, phase 3 trial. The Lancet. Infectious diseases. 2023.
From the study: “There was no effect on cumulative incidence of long COVID with ivermectin (HR 0·99, 95% CI 0·59-1·64) or fluvoxamine”
41% fewer long COVID
Bramante CT et al. Outpatient treatment of COVID-19 and incidence of post-COVID-19 condition over 10 months (COVID-OUT): a multicentre, randomised, quadruple-blind, parallel-group, phase 3 trial. The Lancet. Infectious diseases. 2023.
Hydroxychloroquine did not lower deaths among hospitalized COVID patients.
27.0% died on HCQHydroxychloroquine (HCQ) group's 28-day death rate, vs 25.0% with usual care
In a large UK trial, 27.0% of hospitalized COVID patients given hydroxychloroquine, an arthritis drug, died within 28 days, vs 25.0% of those on usual care, a gap that could be chance. Among those not yet on a ventilator, more on the drug ended up on one or dead: 30.7% vs 26.9%.
Hydroxychloroquine was promoted in 2020 based on lab tests and small studies. This trial ruled out any meaningful survival benefit, and patients on it stayed in the hospital longer. Open-label and limited to hospitalized patients in spring 2020; it did not test the drug for early home treatment or prevention.
See the evidence
A randomized trial (RECOVERY) in UK hospitals, March to June 2020, with 1561 patients given hydroxychloroquine and 3155 given usual care.
From the study: “Death within 28 days occurred in 421 patients (27.0%) in the hydroxychloroquine group and in 790 (25.0%) in the usual-care group”
27.0% died on HCQ
RECOVERY Collaborative Group et al. Effect of Hydroxychloroquine in Hospitalized Patients with Covid-19. The New England journal of medicine. 2020.
Weeks of Paxlovid did not relieve long COVID symptoms.
25 days, no benefitPaxlovid for 15 or 25 days did not ease long COVID symptoms more than placebo
In a US trial of adults with long COVID affecting thinking, automatic body functions such as heart rate on standing, or exercise tolerance, those who took Paxlovid for 15 or 25 days improved no more by day 90 than those on placebo. The trial tested the idea that leftover virus drives long COVID.
Lingering virus is a leading theory of long COVID. In this large, blinded trial, a longer course of the main COVID antiviral pill did not help, so researchers are looking at other approaches. Most participants had been ill for years before treatment, so the trial cannot rule out benefit if given earlier or in specific subgroups.
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An NIH-funded double-blind, placebo-controlled trial (RECOVER-VITAL) of 959 adults with long COVID at 69 US sites, July 2023 to September 2024.
From the study: “Nirmatrelvir-ritonavir for 15 days or 25 days showed no evidence of benefit in long COVID in any of the three phenotypes studied.”
25 days, no benefit
Baden, Lindsey R et al.. Nirmatrelvir-ritonavir targeting viral persistence in post-COVID-19 condition (long COVID) in the USA (RECOVER-VITAL): a randomised, double-blind, placebo-controlled, phase 2 trial.. The Lancet. Infectious diseases. 2026. [Source notice: Correction published 2026-10-30 (10.1016/s1473-3099(26)00586-4): Marta Cerda was added as an author.]
From the study: “In the 959 participants in the mITT population, 643 (67%) self-reported as female”
25 days, no benefit
Baden, Lindsey R et al.. Nirmatrelvir-ritonavir targeting viral persistence in post-COVID-19 condition (long COVID) in the USA (RECOVER-VITAL): a randomised, double-blind, placebo-controlled, phase 2 trial.. The Lancet. Infectious diseases. 2026. [Source notice: Correction published 2026-10-30 (10.1016/s1473-3099(26)00586-4): Marta Cerda was added as an author.]
From the study: “adults who had developed persistent symptoms (≥12 weeks) associated with three major symptom phenotypes (cognitive, autonomic, or exercise) after acute SARS-CoV-2 infection at 69 US sites”
25 days, no benefit
Baden, Lindsey R et al.. Nirmatrelvir-ritonavir targeting viral persistence in post-COVID-19 condition (long COVID) in the USA (RECOVER-VITAL): a randomised, double-blind, placebo-controlled, phase 2 trial.. The Lancet. Infectious diseases. 2026. [Source notice: Correction published 2026-10-30 (10.1016/s1473-3099(26)00586-4): Marta Cerda was added as an author.]
Study-specific findings. Different populations, treatments and follow-up periods can produce different results.
WHEN YOU WANT TO GO DEEPERSee all 7 findingsOriginal results, comparisons and study details.
3 of 3 source groupsFindings stay together with their study.
SOURCE 052 findings
Amoroso, Chiara et al.. VSL#3® supplementation improves fatigue in long COVID: results from the DELong#3 randomized placebo-controlled trial.. British journal of biomedical science. 2026.
Puntmann, Valentina O et al.. Losartan and prednisolone for post-COVID syndrome and cardiac inflammation: a randomized, double-blind, placebo-controlled trial.. Nature communications. 2026.
Change in LV ejection fraction after 16 weeks of losartan plus prednisolone versus placebo in post-COVID syndrome with inflammatory cardiac involvement; the primary unadjusted analysis was neutral despite a positive supportive baseline-adjusted analysis.
Butzin-Dozier, Zachary et al.. SSRI prescription during acute COVID-19 and risk of Long COVID symptoms and conditions among patients with depression.. medRxiv : the preprint server for health sciences. 2026.
Among patients with depression and COVID-19 in a retrospective health-record cohort, SSRI prescription during acute COVID-19 versus no SSRI prescription was associated with lower one-year incidence of gastrointestinal Long COVID symptoms and conditions
Among patients with depression and COVID-19 in a retrospective health-record cohort, SSRI prescription during acute COVID-19 versus no SSRI prescription was associated with lower one-year incidence of general-health Long COVID symptoms and conditions
Among patients with depression and COVID-19 in a retrospective health-record cohort, SSRI prescription during acute COVID-19 versus no SSRI prescription was associated with lower one-year incidence of headache-related Long COVID symptoms and conditions
Among patients with depression and COVID-19 in a retrospective health-record cohort, SSRI prescription during acute COVID-19 versus no SSRI prescription was associated with lower one-year incidence of skin-related Long COVID symptoms and conditions
Browse the 14 original sourcesThe complete bibliography behind this monitor.
[1]
Vanova, Martina et al.. Cognitive Rehabilitation and Functional Outcomes in Long COVID-Related Cognitive Impairment: A Randomized Clinical Trial.. JAMA network open. 2026.
Oppegaard, Oddvar et al.. Nirmatrelvir for acute COVID-19 to prevent long COVID (PANORAMIC Norway): a double-blind, randomised, placebo-controlled trial.. The Lancet. Infectious diseases. 2026.
Butzin-Dozier, Zachary et al.. SSRI prescription during acute COVID-19 and risk of Long COVID symptoms and conditions among patients with depression.. medRxiv : the preprint server for health sciences. 2026.
Puntmann, Valentina O et al.. Losartan and prednisolone for post-COVID syndrome and cardiac inflammation: a randomized, double-blind, placebo-controlled trial.. Nature communications. 2026.
Amoroso, Chiara et al.. VSL#3® supplementation improves fatigue in long COVID: results from the DELong#3 randomized placebo-controlled trial.. British journal of biomedical science. 2026.
Baden, Lindsey R et al.. Nirmatrelvir-ritonavir targeting viral persistence in post-COVID-19 condition (long COVID) in the USA (RECOVER-VITAL): a randomised, double-blind, placebo-controlled, phase 2 trial.. The Lancet. Infectious diseases. 2026. [Source notice: Correction published 2026-10-30 (10.1016/s1473-3099(26)00586-4): Marta Cerda was added as an author.]
Reis, Gilmar et al.. Effect of Fluvoxamine and Metformin for Fatigue in Patients With Long COVID : An Adaptive Randomized Trial.. Annals of internal medicine. 2026.
ATTACC Investigators et al. Therapeutic Anticoagulation with Heparin in Noncritically Ill Patients with Covid-19. The New England journal of medicine. 2021.
Bramante CT et al. Outpatient treatment of COVID-19 and incidence of post-COVID-19 condition over 10 months (COVID-OUT): a multicentre, randomised, quadruple-blind, parallel-group, phase 3 trial. The Lancet. Infectious diseases. 2023.
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