Top 5 — Ranked by Evidence
Moderate
Andrographis
Cough and sore throat comfort during upper respiratory infections
200-1,200 mg/day of extract standardized to >=10% andrographolides, used short term at cold onset; the clearest trial used 200 mg/day.
Moderate
NAC (N-Acetylcysteine)
Respiratory Health and airway mucus clearance
600–1,800 mg/day in divided doses; respiratory: 600 mg twice daily; liver support: 60
Moderate
Black Seed Oil
Nasal and airway comfort
5 mL of oil a day in a honey formulation for 8 weeks, as studied in functional
Moderate
Zinc Acetate
Immune support, studied as lozenges in adults with common colds
13–23 mg elemental zinc per lozenge for cold use (75–100 mg/day total); 50 mg three t
Limited
ImmuseLC-Plasma (Lactococcus lactis strain Plasma)
Fewer days with cough and feeling feverish in healthy adults
100 billion (10¹¹) heat-killed L. lactis strain Plasma/day standard RCT dose. Kirin i
📈 Fastest Growing Respiratory Health Ingredients
Branded ingredients seeing rapid growth in formulator adoption and clinical research in 2024–2026.
Trending
Limited
Quercefit® (Quercetin Phytosome — Indena)
Nasal and Eye Allergy Symptoms in One Placebo-Controlled Trial
250 to 500 mg/day, about 100 to 200 mg quercetin, in the studies; the 1,000 mg/day senolytic…
Trending
Limited
ParActin® (Andrographis Extract — HP Ingredients)
Knee joint comfort and mobility
300 or 600 mg a day for 84 days in the knee trial; ParActin tablets three times a day for 14…
Trending
Limited
ThymoQuin® (Black Seed Oil — TriNutra)
Respiratory and nasal complaints in runners taking ThymoQuin
500 mg/day of ThymoQuin for 4 weeks in runners and for 8 weeks in stressed adults. Other black…
🔬 Future Respiratory Health Ingredients to Watch
Lower current evidence but active research underway — these may become top picks within 2–3 years.
Watch
Limited
Immuse LC-Plasma (Lactococcus lactis Strain Plasma — Kirin)
Fewer days with cough and feeling feverish in healthy adults
100 billion (10¹¹) cells/day in all 8 trials of the 2025 meta-analysis: 6 used heat-killed…
Watch
Limited
Lactobacillus paracasei (Multi-Strain Specialist)
Upper respiratory symptom duration
L. casei 431: at least 1x10^9 CFU/day in an acidified milk drink for 42 days. GM-080: 2x10^9…
Watch
Limited
Elderberry
Upper respiratory symptom duration and severity in controlled trials
Syrup trials used 15 mL of a branded extract (Sambucol) four times daily for 5 days. The…
Recommended Respiratory Health Products
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Real products featuring the best-evidenced respiratory health ingredients ranked above - chosen for clinically-studied forms and doses, third-party testing, and value. Match the supplement to your specific need.
Best when a blood test shows low vitamin D
Amazon →
Sports Research Vitamin D3 5000 IU with Coconut MCT Oil
5,000 IU (125 mcg) softgels, 360 ct
High-potency D3 in coconut MCT oil for absorption, non-GMO verified. Large trials found vitamin D did not prevent respiratory infections in people who were not deficient, and at 5,000 IU each softgel is above the 4,000 IU daily adult upper limit, so it is for correcting a confirmed deficiency rather than year-round protection.
Best for value NAC
Amazon →
NOW NAC 600 mg with Selenium
600 mg veg capsules, 250 ct
Standard 600 mg NAC with selenium and molybdenum cofactors; a glutathione precursor in a large economical bottle.
Best for absorbable quercetin
Amazon →
Thorne Quercetin Phytosome
250 mg quercetin phytosome/capsule, 60 ct
Uses a phytosome complex marketed as far more bioavailable than standard quercetin; popular for seasonal/immune support.
Best for elderberry immune support
Amazon →
Sambucol Black Elderberry Original Formula Syrup
Black elderberry extract syrup, 7.8 fl oz
The original, widely studied black elderberry brand in an easy liquid format; rich in anthocyanin antioxidants.
All Respiratory Health Ingredients (38)
Moderate
Andrographis
Cough and sore throat comfort during upper respiratory infections
200-1,200 mg/day of extract standardized to >=10% andrographolides, used short term at cold onset; the clearest trial used 200 mg/day.
Moderate
NAC (N-Acetylcysteine)
Respiratory Health and airway mucus clearance
600–1,800 mg/day in divided doses; respiratory: 600 mg twice daily; liver support: 60
Moderate
Black Seed Oil
Nasal and airway comfort
5 mL of oil a day in a honey formulation for 8 weeks, as studied in functional
Moderate
Zinc Acetate
Immune support, studied as lozenges in adults with common colds
13–23 mg elemental zinc per lozenge for cold use (75–100 mg/day total); 50 mg three t
Limited
ImmuseLC-Plasma (Lactococcus lactis strain Plasma)
Fewer days with cough and feeling feverish in healthy adults
100 billion (10¹¹) heat-killed L. lactis strain Plasma/day standard RCT dose. Kirin i
Moderate
Zinc Gluconate
Upper respiratory comfort: lozenges studied for symptom duration
15 to 30 mg elemental zinc a day generally; 40 mg a day is the adult upper limit. The cold-lozenge regimen reaches roughly 80 to 100 mg a day and exceeds that limit, so use it for a few days only.
Limited
Codonopsis pilosula (Dang Shen / Poor Man's Ginseng)
COPD herbal formulae meta-analysis
TCM TYPICAL: 9-15 g/day root decoction. oncology adjunct: oral liquid (approved Chine
Limited
Adhatoda vasica (Vasaka, Malabar Nut)
Cough support studied with a standardized herbal combination
No established stand-alone dose. The cough trials used a fixed herbal oral solution
Limited
Echinacea
Fewer Colds: A Small and Contested Effect
Prevention: 2,400 mg/day of an Echinacea purpurea alcoholic extract in adults, 1,200 mg/day in children; treatment used about 10 g of dried root on day 1 then 5 g/day.
Limited
Lactobacillus paracasei (Multi-Strain Specialist)
Upper respiratory symptom duration
L. CASEI 431® RESPIRATORY: ≥1×10⁹ CFU/day × 42 days. KW3110 POLLEN ALLERGY: 4×10¹⁰ CF
Limited
Pelargonium sidoides (EPs 7630)
Chest and airway comfort: symptom scores fell faster than on placebo
EPs 7630 root extract: 30 drops or 20 mg tablets three times daily for 7 days
Limited
Thyme (Thymus vulgaris)
Fewer daytime coughing fits with thyme-ivy and thyme-primrose blends
Blends: thyme-ivy syrup 5.4 mL or one thyme-primrose tablet three times daily for 11
Limited
Limosilactobacillus fermentum (Lactobacillus fermentum)
Respiratory symptom days in endurance athletes (strain VRI-003, sold as PCC)
Strain-specific: 1 x 10^9 to 1.26 x 10^10 CFU/day of VRI-003 (PCC) in athletes; 1 x
Limited
ThymoQuin® (Black Seed Oil — TriNutra)
Respiratory and nasal complaints in runners taking ThymoQuin
500 mg/day of ThymoQuin for 4 weeks in runners and for 8 weeks in stressed adults.
Limited
BLIS K12® (Streptococcus salivarius for ENT — BLIS Technologies)
Oral and upper respiratory immune defenses in children
1 billion CFU/day BLIS K12 (research-validated)
Limited
Garden Nasturtium (Tropaeolum majus)
Respiratory support in a nasturtium-led herbal blend
No standard dose. Nasturtium alone: 1.5 g dried leaf and flower powder twice daily for
Limited
Ivy Leaf Extract
Expectorant support for a productive cough
EA 575 dry extract 105 mg/day as a liquid for 7 days in placebo-controlled adult
Limited
Quercefit® (Quercetin Phytosome — Indena)
Nasal and Eye Allergy Symptoms in One Placebo-Controlled Trial
250 to 500 mg/day, about 100 to 200 mg quercetin, in the studies; the 1,000 mg/day senolytic figure comes from trials pairing quercetin with a prescription drug, not tested for this product.
Limited
AlvioLife® (Respiratory Health & Performance)
Breathing-related quality of life improved versus placebo
Per AlvioLife® clinical dosing; PLT Health Solutions product specifications
Limited
Berriqi® (Boysenberry and Apple Polyphenols — Anagenix)
Airway and respiratory support
No standard human dose has been established; the one human trial gave capsules daily for 5 days before ozone exposure. Products vary widely in content, so check the label.
Limited
CM-Glucan™ Nu
Seasonal immune and upper-respiratory support (reported)
100 mg/day
Limited
Elderberry
Upper respiratory symptom duration and severity in controlled trials
Syrup trials used 15 mL of a branded extract (Sambucol) four times daily for 5 days.
Limited
PROMUNEL® (Propolis Immune Extract)
Upper respiratory comfort in a 5-day throat spray trial
400–800 mg/day propolis extract; PROMUNEL® clinical dose per PLT specifications; immu
Limited
Licorice Root (Glycyrrhiza glabra)
Throat and cough: gargles, lozenges, and one small pastille trial
75 mg twice daily of a deglycyrrhizinated extract in the dyspepsia trial. The EU advises no more than 100 mg glycyrrhizin a day.
Limited
Slippery Elm
Upper respiratory comfort: soothes a sore throat as a slow-dissolving lozenge
No trial has tested slippery elm alone; traditional oral use is 2 to 4 g powdered inner bark in water 3 to 4 times daily, or 400 to 500 mg capsules 3 times daily.
Limited
Verilla® (Perilla Extract for Seasonal Allergy)
Nasal and eye comfort
Around 50 to 200 mg of rosmarinic acid per day.
Moderate
Quercetin
Nasal and eye comfort in pollen season
500-1,000 mg/day; in pooled blood pressure trials 500 mg/day or more worked while doses below 500 mg/day did nothing, and many products supply well under 500 mg.
Limited
Rosmarinic Acid
Studied in people with seasonal hay fever
One hay fever trial used a Perilla frutescens extract supplying 50 mg or 200 mg of rosmarinic acid a day for 21 days; doses for cognition or anxiety are not established here.
Moderate
Bromelain
Sinus comfort as an add-on to standard care
100 to 1,000 mg/day in divided doses in trials of bromelain alone
Moderate
Menthol
Sensation of easier nasal breathing (menthol lozenge)
IBS (enteric-coated peppermint oil): 180-225 mg three times daily; menthol is only one component of peppermint oil, and no cited trial tested isolated menthol.
Limited
Borage Leaf and Flower (Borago officinalis)
Breathing symptoms and control scores in one placebo-controlled trial
No recommended dose exists. The one human trial gave 5 mL of a flower and leaf extract
Limited
Butterbur (Petasites hybridus)
Allergic rhinitis symptom relief
Migraine trial: 2 capsules of 25 mg twice daily of a PA-free standardized extract; market doses and extract strengths vary widely.
Limited
Tinofend® (Tinospora cordifolia for Immune — Verdure)
Seasonal nasal comfort — what one small trial reported
Per Verdure Tinofend product specification
Preliminary
Elderflower (Sambucus nigra Flower)
Upper respiratory symptom comfort studied in multi-herb formulas
No dose of elder flower alone is established in controlled trials. It is traditionally
Preliminary
Elecampane (Inula helenium)
Traditional expectorant for cough and chest congestion
No trial of elecampane alone; traditional dose 1.5-4 g dried root as a decoction or
Preliminary
Isenolic® (Olive Polyphenols for Cold/Flu)
Antiviral activity against a respiratory virus in lab cells only (maker-funded)
Per Pharmactive product specification
Preliminary
Marshmallow Root
Dry cough scores in a small placebo-controlled trial of marshmallow drops
Placebo trial: 40 mg Althaea officinalis as 20 drops three times daily for 4 weeks
Preliminary
Eyebright (Euphrasia officinalis)
Upper respiratory mucosal support
Traditional amounts only: 400-800 mg/day dried herb or extract, or a tea from 1-2 g dried herb, 2-3 cups/day. No controlled trial has tested any oral dose of eyebright.