Condition

Common Cold

The common cold is a viral infection of the nose and throat, most often caused by rhinoviruses, where the immune response brings inflammation that causes a runny nose, congestion, sore throat and cough. Zinc and elderberry have the best support, and trials found cold symptoms improved with both, though the effects were small. Elderberry's results came from just three small studies, and vitamin C showed no clear difference in how often people caught colds.

Sources: PMID 33827515; PMID 30670267

Supplements studied: 10
Graded outcomes: 11
Trials: 68
People studied: 35,740

Evidence by supplement

Strong
Moderate
Limited
Very limited

10 supplements

Umckaloabo

Umckaloabo: outcomes studied for Common Cold
Grade	Outcome	Effect	Size	Studies	People
	Bronchitis Symptoms Moderate Improvement	Improves (the measure goes down)	Moderate effect	4 studies	644 people
Studies that measured bronchitis symptoms Pelargonium sidoides for acute bronchitis: a systematic review and meta-analysisPhytomedicine · PMID 18222667 Treatment of acute bronchitis with EPs 7630: randomized, controlled trial in children and adolescentsPediatr Int · PMID 22360575 Effects of Pelargonium sidoides extract EPs 7630 on acute cough and quality of life - a meta-analysis of randomized, placebo-controlled trials.Multidiscip Respir Med · PMID 36051888 and 1 more on the Umckaloabo page
	Fever	Improves (the measure goes up)		2 studies	131 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
	Common Cold Symptoms	Improves (the measure goes down)		1 study	832 people
Studies that measured common cold symptoms Treatment of signs and symptoms of the common cold using EPs 7630 - results of a meta-analysis.Heliyon · PMID 31844762
	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	131 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
	Upper Respiratory Tract Infection Symptoms	Improves (the measure goes down)		1 study	28 people
	Headaches	Improves (the measure goes down)			103 people

Elderberry

Elderberry: outcomes studied for Common Cold
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Upper Respiratory Tract Infection Symptoms Small Improvement	Improves (the measure goes down)	Small effect	3 studies	180 people
Studies that measured upper respiratory tract infection symptoms Elderberry Extract Outpatient Influenza Treatment for Emergency Room Patients Ages 5 and Above: a Randomized, Double-Blind, Placebo-Controlled Trial.J Gen Intern Med · PMID 32929634 Elderberry for prevention and treatment of viral respiratory illnesses: a systematic review.BMC Complement Med Ther · PMID 33827515 Black elderberry (Sambucus nigra) supplementation effectively treats upper respiratory symptoms: A meta-analysis of randomized, controlled clinical trials.Complement Ther Med · PMID 30670267

Vitamin D

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

Vitamin D: outcomes studied for Common Cold
Grade	Outcome	Effect	Size	Studies	People
	Influenza Risk Small Improvement	Improves (the measure goes down)	Small effect	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
	Upper Respiratory Tract Infection Risk	Changes; see studies		13 studies	5,265 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	2,352 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
	Lower Respiratory Tract Infection Risk	Changes; see studies			240 people

King of Bitters

Upper Respiratory Tract Infection Symptoms: improves
Sore Throat Symptoms: improves

King of Bitters: outcomes studied for Common Cold
Grade	Outcome	Effect	Size	Studies	People
	Upper Respiratory Tract Infection Symptoms Moderate Improvement	Improves (the measure goes down)	Moderate effect	1 study	316 people
Studies that measured upper respiratory tract infection symptoms Use of visual analogue scale measurements (VAS) to asses the effectiveness of standardized Andrographis paniculata extract SHA-10 in reducing the symptoms of common cold. A randomized double blind-placebo studyPhytomedicine · PMID 10589439
	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

Zinc

Common Cold Symptoms: improves
Diarrhea Symptoms: improves
Upper Respiratory Tract Infection Symptoms: improves

Zinc: outcomes studied for Common Cold
Grade	Outcome	Effect	Size	Studies	People
	Common Cold Symptoms Small Improvement	Improves (the measure goes down)	Small effect		1,377 people
	Diarrhea Symptoms Small Improvement	Improves (the measure goes down)	Small effect	4 studies	100 people
Studies that measured diarrhea symptoms Oral zinc for treating diarrhoea in children.Cochrane Database Syst Rev · PMID 27996088 Oral zinc supplementation for the treatment of acute diarrhea in children: a systematic review and meta-analysis.Nutrients · PMID 24284615 Zinc supplementation for treating diarrhea in children: a systematic review and meta-analysis.Rev Panam Salud Publica · PMID 23764669 and 1 more on the Zinc page
	Upper Respiratory Tract Infection Symptoms	Improves (the measure goes down)		11 studies	2,641 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
	Upper Respiratory Tract Infection Risk	Changes; see studies		1 study	528 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

Echinacea

CD3 Lymphocytes: improves
CD4 Lymphocytes
Upper Respiratory Tract Infection Risk: changes; see studies

Echinacea: outcomes studied for Common Cold
Grade	Outcome	Effect	Size	Studies	People
	CD3 Lymphocytes Small Increase	Improves (the measure goes up)	Small effect		62 people
	CD4 Lymphocytes No effect		NoneNo effect		62 people
	Upper Respiratory Tract Infection Risk	Changes; see studies		10 studies	2,031 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
	Common Cold Symptoms	Improves (the measure goes down)		9 studies	390 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 Symptoms	Improves (the measure goes down)		1 study	1,258 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
	Lymphocyte Count	Improves (the measure goes up)			62 people
	Monocyte Count	Improves (the measure goes up)			62 people
	Neutrophil Activity	Improves (the measure goes up)			62 people
	Neutrophil Count	Improves (the measure goes up)			62 people
	White Blood Cell Count	Improves (the measure goes up)			62 people

Vitamin C

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

Vitamin C: outcomes studied for Common Cold
Grade	Outcome	Effect	Size	Studies	People
	Upper Respiratory Tract Infection Risk No effect		NoneNo effect	5 studies	21,620 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
	Common Cold Symptoms No effect		NoneNo effect	1 study	3,001 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	14,426 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

Ephedrine

Nasal Congestion: improves

Ephedrine: outcomes studied for Common Cold
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Nasal Congestion	Improves (the measure goes up)		1 study	52 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

ECA

Nasal Congestion: improves

ECA: outcomes studied for Common Cold
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Nasal Congestion	Improves (the measure goes up)		1 study	643 people
Studies that measured nasal congestion Clinical, double-blind, placebo-controlled study investigating the combination of acetylsalicylic acid and pseudoephedrine for the symptomatic treatment of nasal congestion associated with common coldArzneimittelforschung · PMID 15500197

Panax Ginseng (Korean Ginseng)

Vaccine Augmentation: improves

Panax Ginseng (Korean Ginseng): outcomes studied for Common Cold
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Vaccine Augmentation	Improves (the measure goes up)		1 study	227 people
Studies that measured vaccine augmentation Efficacy and safety of the standardised Ginseng extract G115 for potentiating vaccination against the influenza syndrome and protection against the common cold correctedDrugs Exp Clin Res · PMID 8879982

Key findings

Bronchitis SymptomsUmckaloaboImproves (the measure goes down)
Upper Respiratory Tract Infection SymptomsElderberryImproves (the measure goes down)
Influenza RiskVitamin DImproves (the measure goes down)

The Common Cold protocol

2 primary supplements · 2 supporting supplements

Zinc75 mg daily as lozenges (within 24h of symptom onset)
Vitamin C1–2 g daily (increase during illness)

See the full protocol

Shop the evidence-backed picks

Fullscript collectionImmune support: evidence-graded picksOpen on Fullscript

The collection holds the supplements we grade A or B for its theme, in third-party tested products where the catalog has them. It opens in our Fullscript store. You can look through it without signing in; Fullscript asks for a free account to order.

Or shop one supplement

The supplements graded A or B for Common Cold. Each opens third-party tested products for that supplement.

Grade A
Grade B
Grade B
Grade B
Grade B

We earn from purchases made in our Fullscript store, and links to Fullscript, iHerb or Thorne carry our referral, so we may earn a commission at no extra cost to you. Grades come from the research and never change based on what we earn. Full disclosure

Studies cited

3 studies from PubMed

Preventing the common cold with a garlic supplement: a double-blind, placebo-controlled surveyAdv Ther · PMID 11697022
Supplementation with aged garlic extract improves both NK and γδ-T cell function and reduces the severity of cold and flu symptoms: a randomized, double-blind, placebo-controlled nutrition interventionClin Nutr · PMID 22280901
Visiting a sauna: does inhaling hot dry air reduce common cold symptoms? A randomised controlled trial.Med J Aust · PMID 21143077

Evidence by supplement

Key findings

The Common Cold protocol

Shop the evidence-backed picks

Studies cited

Related conditions

Supplement stack for Common Cold