Condition

Upper Respiratory Tract Infection

An upper respiratory tract infection is a usually viral illness of the nose, throat, or sinuses, such as the common cold, in which the body's immune response causes congestion, sore throat, and cough. Among supplements, beta-glucans have the clearest support: a review found people had fewer infections, and the evidence is moderate. Echinacea eased cold symptoms in small studies, but the evidence is limited, and vitamin C and zinc showed no clear difference in the few trials reviewed here.

Sources: PMID 33900466; PMID 16678640

Updated 30 September 2026
How we grade
1 study cited
Upper Respiratory Tract Infection protocol

Supplements studied: 14
Graded outcomes: 13
Trials: 43
People studied: 26,798

Evidence by supplement

Strong
Moderate
Limited
Very limited

14 supplements

Beta-glucans

Beta-glucans: outcomes studied for Upper Respiratory Tract Infection
Grade	Outcome	Effect	Size	Studies	People
	Upper Respiratory Tract Infection Risk Small Improvement	Improves (the measure goes down)	Small effect	1 study	2,465 people
Studies that measured upper respiratory tract infection risk Effects of yeast β-glucans for the prevention and treatment of upper respiratory tract infection in healthy subjects: a systematic review and meta-analysis.Eur J Nutr · PMID 33900466
	Upper Respiratory Tract Infection Symptoms	Changes; see studies			2,465 people

Echinacea

Echinacea: outcomes studied for Upper Respiratory Tract Infection
Grade	Outcome	Effect	Size	Studies	People
	Common Cold Symptoms Small Improvement	Improves (the measure goes down)	Small effect	9 studies	567 people
Studies that measured common cold symptoms Echinacea in the prevention of induced rhinovirus colds: a meta-analysisClin Ther · PMID 16678640 Echinacea purpurea therapy for the treatment of the common cold: a randomized, double-blind, placebo-controlled clinical trialArch Intern Med · PMID 15197051 An evaluation of Echinacea angustifolia in experimental rhinovirus infectionsN Engl J Med · PMID 16049208 and 6 more on the Echinacea page
	Upper Respiratory Tract Infection Risk	Changes; see studies		10 studies	832 people
Studies that measured upper respiratory tract infection risk Echinacea for the prevention and treatment of upper respiratory tract infections: A systematic review and meta-analysisComplement Ther Med · PMID 31126553 Echinacea purpurea for prevention of experimental rhinovirus coldsClin Infect Dis · PMID 15156472 Safety and Efficacy Profile of Echinacea purpurea to Prevent Common Cold Episodes: A Randomized, Double-Blind, Placebo-Controlled TrialEvid Based Complement Alternat Med · PMID 23024696 and 7 more on the Echinacea page
	Upper Respiratory Tract Infection Symptoms	Improves (the measure goes down)		1 study	981 people
Studies that measured upper respiratory tract infection symptoms Efficacy of Echinacea purpurea in patients with a common cold. A placebo-controlled, randomised, double-blind clinical trialArzneimittelforschung · PMID 11505787

Ephedrine

Heart Rate: improves
Nasal Congestion: improves

Ephedrine: outcomes studied for Upper Respiratory Tract Infection
Grade	Outcome	Effect	Size	Studies	People
	Heart Rate Small Increase	Improves (the measure goes down)	Small effect	1 study	238 people
Studies that measured heart rate Efficacy and safety of single and multiple doses of pseudoephedrine in the treatment of nasal congestion associated with common coldAm J Rhinol · PMID 15794071
	Nasal Congestion	Improves (the measure goes up)		1 study	238 people
Studies that measured nasal congestion The effects of oral pseudoephedrine on nasal patency in the common cold: a double-blind single-dose placebo-controlled trialClin Otolaryngol Allied Sci · PMID 10196648

King of Bitters

Sore Throat Symptoms: improves
Upper Respiratory Tract Infection Risk: changes; see studies

King of Bitters: outcomes studied for Upper Respiratory Tract Infection
Grade	Outcome	Effect	Size	Studies	People
	Sore Throat Symptoms Moderate Improvement	Improves (the measure goes down)	Moderate effect	1 study	152 people
Studies that measured sore throat symptoms Efficacy of Andrographis paniculata, Nees for pharyngotonsillitis in adultsJ Med Assoc Thai · PMID 1797953
	Upper Respiratory Tract Infection Risk	Changes; see studies		1 study	223 people
Studies that measured upper respiratory tract infection risk A randomized double blind placebo controlled clinical evaluation of extract of Andrographis paniculata (KalmCold) in patients with uncomplicated upper respiratory tract infectionPhytomedicine · PMID 20092985

Umckaloabo

Asthma Symptoms: improves
Fever: improves
Cough: changes; see studies

Umckaloabo: outcomes studied for Upper Respiratory Tract Infection
Grade	Outcome	Effect	Size	Studies	People
	Asthma Symptoms Small Improvement	Improves (the measure goes down)	Small effect	1 study	61 people
Studies that measured asthma symptoms Can the Pelargonium sidoides root extract EPs® 7630 prevent asthma attacks during viral infections of the upper respiratory tract in childrenPhytomedicine · PMID 23142309
	Fever	Improves (the measure goes up)		2 studies	61 people
Studies that measured fever Efficacy of a pelargonium sidoides preparation in patients with the common cold: a randomized, double blind, placebo-controlled clinical trialExplore · PMID 18005909 The efficacy of Pelargonium sidoides in the treatment of upper respiratory tract infections in children with transient hypogammaglobulinemia of infancyPhytomedicine · PMID 22809962
	Cough	Changes; see studies		1 study	746 people
Studies that measured cough Herbal Medicine for Cough: a Systematic Review and Meta-Analysis.Forsch Komplementmed · PMID 26840418
	Nasal Congestion	Improves (the measure goes up)		1 study	61 people
Studies that measured nasal congestion Treatment of acute rhinosinusitis with the preparation from Pelargonium sidoides EPs 7630: a randomized, double-blind, placebo-controlled trialRhinology · PMID 19382496

Vitamin D

Bacterial Infection: improves
Body Fat: improves
Upper Respiratory Tract Infection Risk: changes; see studies

Vitamin D: outcomes studied for Upper Respiratory Tract Infection
Grade	Outcome	Effect	Size	Studies	People
	Bacterial Infection Moderate Improvement	Improves (the measure goes up)	Moderate effect		140 people
	Body Fat Small Decrease	Improves (the measure goes down)	Small effect		25 people
	Upper Respiratory Tract Infection Risk	Changes; see studies		13 studies	18,909 people
Studies that measured upper respiratory tract infection risk The effects of prenatal vitamin D supplementation on respiratory and allergy-related outcomes in children: A systematic review and meta-analysis of randomized controlled trials.World Allergy Organ J · PMID 40535465 High-Dose Monthly Vitamin D for Prevention of Acute Respiratory Infection in Older Long-Term Care Residents: A Randomized Clinical TrialJ Am Geriatr Soc · PMID 27861708 Randomized trial of vitamin D supplementation and risk of acute respiratory infection in MongoliaPediatrics · PMID 22908115 and 10 more on the Vitamin D page
	Upper Respiratory Tract Infection Symptoms	Improves (the measure goes down)		13 studies	2,971 people
Studies that measured upper respiratory tract infection symptoms Double-blind randomised placebo-controlled trial of bolus-dose vitamin D3 supplementation in adults with asthma (ViDiAs)Thorax · PMID 25724847 Vitamin D Supplementation and the Risk of Colds in Patients with AsthmaAm J Respir Crit Care Med · PMID 26540136 Vitamin D supplementation and upper respiratory tract infections in adolescent swimmers: a randomized controlled trialPediatr Exerc Sci · PMID 25050610 and 10 more on the Vitamin D page
	Influenza Risk	Changes; see studies		2 studies	2,003 people
Studies that measured influenza risk Vitamin D supplementation did not prevent influenza-like illness as diagnosed retrospectively by questionnaires in subjects participating in randomized clinical trialsScand J Infect Dis · PMID 22026455 Effects of vitamin D supplements on influenza A illness during the 2009 H1N1 pandemic: a randomized controlled trialFood Funct · PMID 25088394
	Weight	Improves (the measure goes down)		2 studies	25 people
	Fever	Improves (the measure goes up)		1 study	164 people
	Muscle Mass	Improves (the measure goes up)		1 study	25 people
	Cough	Changes; see studies			164 people
	Lower Respiratory Tract Infection Risk	Changes; see studies			5,110 people

Vitamin E

All-Cause Mortality
Weight: improves
Hemoglobin: improves

Vitamin E: outcomes studied for Upper Respiratory Tract Infection
Grade	Outcome	Effect	Size	Studies	People
	All-Cause Mortality No effect		NoneNo effect	2 studies	451 people
Studies that measured all-cause mortality Vitamin E in the primary prevention of cardiovascular disease and cancer: the Women's Health Study: a randomized controlled trialJAMA · PMID 15998891 Vitamin E supplementation and cataract: randomized controlled trialOphthalmology · PMID 14711717
	Weight	Improves (the measure goes down)		1 study	451 people
Studies that measured weight Vitamin E and respiratory tract infections in elderly nursing home residents: a randomized controlled trialJAMA · PMID 15315997
	Hemoglobin	Improves (the measure goes up)			451 people
	Immunity	Improves (the measure goes up)			902 people
	Upper Respiratory Tract Infection Risk	Changes; see studies			451 people

Zinc

Upper Respiratory Tract Infection Risk
Upper Respiratory Tract Infection Symptoms: improves

Zinc: outcomes studied for Upper Respiratory Tract Infection
Grade	Outcome	Effect	Size	Studies	People
	Upper Respiratory Tract Infection Risk No effect		NoneNo effect	1 study	100 people
Studies that measured upper respiratory tract infection risk Zinc supplementation decreases incidence of infections in the elderly: effect of zinc on generation of cytokines and oxidative stressAm J Clin Nutr · PMID 17344507
	Upper Respiratory Tract Infection Symptoms	Improves (the measure goes down)		11 studies	348 people
Studies that measured upper respiratory tract infection symptoms Prophylaxis and treatment of rhinovirus colds with zinc gluconate lozengesJ Antimicrob Chemother · PMID 3440773 Two randomized controlled trials of zinc gluconate lozenge therapy of experimentally induced rhinovirus coldsAntimicrob Agents Chemother · PMID 2820298 Zinc gluconate and the common cold: a controlled clinical studyJ Int Med Res · PMID 1397668 and 8 more on the Zinc page

Vitamin C

Common Cold Symptoms
Upper Respiratory Tract Infection Symptoms: improves
Upper Respiratory Tract Infection Risk: changes; see studies

Vitamin C: outcomes studied for Upper Respiratory Tract Infection
Grade	Outcome	Effect	Size	Studies	People
	Common Cold Symptoms No effect		NoneNo effect	1 study	1,731 people
Studies that measured common cold symptoms Ineffectiveness of vitamin C in treating coryza.Practitioner · PMID 4870463
	Upper Respiratory Tract Infection Symptoms	Improves (the measure goes down)		24 studies	4,935 people
Studies that measured upper respiratory tract infection symptoms Vitamin C and the common cold: a double-blind trialCan Med Assoc J · PMID 5057006 Ascorbic acid and the common coldLancet · PMID 4113614 Preventing the common cold with a vitamin C supplement: a double-blind, placebo-controlled surveyAdv Ther · PMID 12201356 and 21 more on the Vitamin C page
	Upper Respiratory Tract Infection Risk	Changes; see studies		5 studies	8,012 people
Studies that measured upper respiratory tract infection risk Vitamin C supplementation reduces the odds of developing a common cold in Republic of Korea Army recruits: randomised controlled trialBMJ Mil Health · PMID 32139409 The effects of ascorbic acid and flavonoids on the occurrence of symptoms normally associated with the common coldAm J Clin Nutr · PMID 463806 The clinical and biochemical effects of vitamin C supplementation in short-stay hospitalized geriatric patientsInt J Vitam Nutr Res · PMID 6376396 and 2 more on the Vitamin C page

Resveratrol

Upper Respiratory Tract Infection Risk
Upper Respiratory Tract Infection Symptoms: improves

Resveratrol: outcomes studied for Upper Respiratory Tract Infection
Grade	Outcome	Effect	Size	Studies	People
	Upper Respiratory Tract Infection Risk No effect		NoneNo effect	1 study	39 people
Studies that measured upper respiratory tract infection risk Effects of Nasal Solution Incorporating Resveratrol and Carboxymethyl-Β-Glucan in Preschool Non-Atopic Children with Wheezing.Nutrients · PMID 39064639
	Upper Respiratory Tract Infection Symptoms	Improves (the measure goes down)			39 people

Lactobacillus Casei

Immunity
Immunoglobulin A: improves
Immunoglobulin G: improves

Lactobacillus Casei: outcomes studied for Upper Respiratory Tract Infection
Grade	Outcome	Effect	Size	Studies	People
	Immunity No effect		NoneNo effect		47 people
	Immunoglobulin A	Improves (the measure goes up)		2 studies	131 people
Studies that measured immunoglobulin a Daily probiotic's (Lactobacillus casei Shirota) reduction of infection incidence in athletesInt J Sport Nutr Exerc Metab · PMID 21411836 Effect of a probiotics supplementation on respiratory infections and immune and hormonal parameters during intense military trainingMil Med · PMID 17937368
	Immunoglobulin G	Improves (the measure goes up)			84 people
	Upper Respiratory Tract Infection Risk	Changes; see studies			131 people
	White Blood Cell Count	Improves (the measure goes up)			84 people

Colostrum

C-Reactive Protein (CRP)
Weight: improves
Upper Respiratory Tract Infection Symptoms: improves

Colostrum: outcomes studied for Upper Respiratory Tract Infection
Grade	Outcome	Effect	Size	Studies	People
	C-Reactive Protein (CRP) No effect		NoneNo effect		43 people
	Weight	Improves (the measure goes down)		5 studies	43 people
Studies that measured weight The effects of bovine colostrum supplementation on body composition and exercise performance in active men and womenNutrition · PMID 11312068 Effect of bovine colostrum supplementation on the composition of resistance trained and untrained limbs in healthy young menEur J Appl Physiol · PMID 14504943 Effect of bovine colostrum on anaerobic exercise performance and plasma insulin-like growth factor IJ Sports Sci · PMID 12848392 and 2 more on the Colostrum page
	Upper Respiratory Tract Infection Symptoms	Improves (the measure goes down)		4 studies	249 people
Studies that measured upper respiratory tract infection symptoms The effect of bovine colostrum supplementation on salivary IgA in distance runnersInt J Sport Nutr Exerc Metab · PMID 16676703 Effect of bovine colostrum supplementation on respiratory tract mucosal defenses in swimmersInt J Sport Nutr Exerc Metab · PMID 20601740 Concentrated bovine colostrum protein supplementation reduces the incidence of self-reported symptoms of upper respiratory tract infection in adult malesEur J Nutr · PMID 12923655 and 1 more on the Colostrum page
	Immunoglobulin A	Improves (the measure goes up)		1 study	75 people
Studies that measured immunoglobulin a The effect of bovine colostrum on viral upper respiratory tract infections in children with immunoglobulin A deficiencyClin Respir J · PMID 21801330
	Immunoglobulin M	Improves (the measure goes up)		1 study	43 people
Studies that measured immunoglobulin m Modulation of human humoral immune response through orally administered bovine colostrumFEMS Immunol Med Microbiol · PMID 11549415
	Immunoglobulin G	Improves (the measure goes up)			43 people
	Upper Respiratory Tract Infection Risk	Changes; see studies			217 people

Elderberry

Upper Respiratory Tract Infection Symptoms: improves

Elderberry: outcomes studied for Upper Respiratory Tract Infection
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Upper Respiratory Tract Infection Symptoms	Improves (the measure goes down)		3 studies	180 people

ECA

Pain: improves

ECA: outcomes studied for Upper Respiratory Tract Infection
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Pain	Improves (the measure goes down)		1 study	640 people

Key findings

Upper Respiratory Tract Infection RiskBeta-glucansImproves (the measure goes down)
Common Cold SymptomsEchinaceaImproves (the measure goes down)
Heart RateEphedrineImproves (the measure goes down)

The Upper Respiratory Tract Infection (Common Cold) Prevention & Support protocol

2 primary supplements · 7 supporting supplements

Vitamin C200–1,000 mg daily for prevention; 1–2 g daily during illness
Zinc15–30 mg daily prevention; 75 mg+ daily as lozenges (acetate or gluconate) when ill

See the full protocol

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Studies cited

1 study from PubMed

Effectiveness of honey for symptomatic relief in upper respiratory tract infections: a systematic review and meta-analysisBMJ Evid Based Med · PMID 32817011

Evidence by supplement

Key findings

The Upper Respiratory Tract Infection (Common Cold) Prevention & Support protocol

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Studies cited

Related conditions

Supplement stack for Upper Respiratory Tract Infection