Knowledge · Topics
Viral Infections
What has been investigated regarding antiviral properties—and which findings apply to humans?
Antiviral effects can be readily demonstrated in the laboratory but are difficult to substantiate in humans. This very gap makes the field difficult to navigate.
1. Which Substances Have Been Investigated for This Purpose
The overview shows how many studies exist per substance and type of investigation. A single study may be assigned to multiple topics—therefore, the numbers cannot be summed but instead describe this specific subset.
| Substance | in humans | of which controlled | human tissue | preliminary work |
|---|---|---|---|---|
| Chronic inflammation | 159 | 9 | 1 | 90 |
| Vitamin D | 145 | 36 | 1 | 33 |
| Gut microbiome | 129 | 7 | 13 | 122 |
| Adaptogens | 45 | 16 | 4 | 74 |
| Turmeric and curcumin | 44 | 10 | 1 | 69 |
| Humic acid complexes | 7 | 4 | 1 | 42 |
2. All Substances and Therapies with Controlled Studies on Viral Infections
14 substance and therapy pages assign controlled human studies to this area. The number comes from each page; one study can belong to several areas.
3. The Most Robust Studies
Ranked by evidential strength, not by prominence.
Controlled Human Trial
- 1 "Effect of calcifediol treatment and best available therapy versus best available therapy on intensive care unit admission and mortality among patients (2020)"
- 2 Vitamin D receptor stimulation to reduce acute respiratory distress syndrome (ARDS) in patients with coronavirus SARS-CoV-2 infections: Revised Ms SBM (2020)
- 3 Oral Curcumin With Piperine as Adjuvant Therapy for the Treatment of COVID-19: A Randomized Clinical Trial (2021)
- 4 Treatment With 25-Hydroxyvitamin D<sub>3</sub> (Calcifediol) Is Associated With a Reduction in the Blood Neutrophil-to-Lymphocyte Ratio Marker of Disease (2021)
- 5 Positive Effects of Vitamin D Supplementation in Patients Hospitalized for COVID-19: A Randomized, Double-Blind, Placebo-Controlled Trial (2022)
- 6 Vitamin D Supplementation in COVID-19 Patients: A Clinical Case Series (2020)
- 7 Stimulating the Resolution of Inflammation Through Omega-3 Polyunsaturated Fatty Acids in COVID-19: Rationale for the <i>COVID-Omega-F</i> Trial (2020)
- 8 Low vitamin D levels do not aggravate COVID-19 risk or death, and vitamin D supplementation does not improve outcomes in hospitalized patients with COVID-19 (2021)
- 9 Oral nano-curcumin formulation efficacy in the management of mild to moderate outpatient COVID-19: A randomized triple-blind placebo-controlled clinical trial (2021)
- 10 Randomized placebo-controlled pilot clinical trial on the efficacy of ayurvedic treatment regime on COVID-19 positive patients (2021)
- 11 Clinical significance of micronutrient supplements in patients with coronavirus disease 2019: A comprehensive systematic review and meta-analysis (2022)
- 12 Nutritional risk of vitamin D, vitamin C, zinc, and selenium deficiency on risk and clinical outcomes of COVID-19: A narrative review (2022)
- 13 The Efficacy of Multivitamin, Vitamin A, Vitamin B, Vitamin C, and Vitamin D Supplements in the Prevention and Management of COVID-19 and Long COVID: A Review (2024)
- 14 A standardised ashwagandha root extract alleviates stress, anxiety, and improves quality of life in healthy adults by modulating stress hormones: Results of a Study (2023)
- 15 Findings from Russian literature on the clinical application of Eleutherococcus senticosus (Rupr. & Maxim.): A narrative review (2021)
- 16 Insufficient evidence for vitamin D use in COVID-19: A rapid systematic review (2021)
- 17 Efficacy of Adaptogens in Patients with Long COVID: A Randomised, Quadruple-Blind, Placebo-Controlled Trial (2022)
- 18 Effects of curcumin-piperine co-supplementation on clinical signs, duration, severity, and inflammatory markers in patients with COVID-19: A structured review (2020)
- 19 Hospital and laboratory outcomes of patients with COVID-19 who received vitamin D supplementation: A systematic review and meta-analysis of randomised controlled trials (2023)
- 20 Emerging Evidence on Balneotherapy and Thermal Interventions in Post-COVID-19 Syndrome: A Systematic Review (2025)
Sources
- 1Entrenas Castillo M, Entrenas Costa LM, Vaquero Barrios JM, Alcalá Díaz JF, López Miranda J, Bouillon R et al. · 2020
- 2Quesada-Gomez JM, Entrenas-Castillo M, Bouillon R · 2020
- 3Pawar KS, Mastud RN, Pawar SK, Pawar SS, Bhoite RR, Bhoite RR et al. · 2021
- 4Maghbooli Z, Sahraian MA, Jamalimoghadamsiahkali S, Asadi A, Zarei A, Zendehdel A et al. · 2021
- 5De Niet S, Trémège M, Coffiner M, Rousseau AF, Calmes D, Frix AN et al. · 2022
- 6Ohaegbulam KC, Swalih M, Patel P, Smith MA, Perrin R · 2020
- 7Arnardottir H, Pawelzik SC, Öhlund Wistbacka U, Artiach G, Hofmann R, Reinholdsson I et al. · 2020
- 8
- 9Ahmadi R, Salari S, Sharifi MD, Reihani H, Rostamiani MB, Behmadi M et al. · 2021
- 10Devpura G, Tomar BS, Nathiya D, Sharma A, Bhandari D, Haldar S et al. · 2021
- 11Beran A, Mhanna M, Srour O, Ayesh H, Stewart JM, Hjouj M et al. · 2022
- 12Pedrosa LFC, Barros ANAB, Leite-Lais L · 2022
- 13Sinopoli A, Sciurti A, Isonne C, Santoro MM, Baccolini V · 2024
- 14
- 15Gerontakos S, Taylor A, Avdeeva AY, Shikova VA, Pozharitskaya ON, Casteleijn D et al. · 2021
- 16da Rocha AP, Atallah AN, Aldrighi JM, Pires ALR, Dos Santos Puga ME, Pinto ACPN · 2021
- 17Karosanidze I, Kiladze U, Kirtadze N, Giorgadze M, Amashukeli N, Parulava N et al. · 2022
- 18Miryan M, Bagherniya M, Sahebkar A, Soleimani D, Rouhani MH, Iraj B et al. · 2020
- 19Zaazouee MS, Eleisawy M, Abdalalaziz AM, Elhady MM, Ali OA, Abdelbari TM et al. · 2023
- 20Elisabetta Ferrara, Manela Scaramuzzino, Giovanna Murmura, Gianmaria D’Addazio, Bruna Sinjari · Healthcare · 2025
Every statement on this page carries its evidence tier — proven, plausible or hypothesis — and leads to the original work. The decision in the individual case rests with the practitioner; we provide the connections.