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Immune Active

Metagenics
4.9
★ ★ ★ ★ ★
(66 ratings)
Zinc 30 mg
Green Tea 375 mg
Product Image
Score76
A strong antioxidant-immune formula with useful NAC and quercetin, but high zinc and premium cost limit long-term appeal.
How scoring works
Quantity:60 Capsule(s) • (30 servings)
Goals:
General Health
Immunity
Anti-Inflammatory Support
Skin Health
Anti-Aging

Score 76

A strong antioxidant-immune formula with useful NAC and quercetin, but high zinc and premium cost limit long-term appeal.
How scoring works
$42.95($1.43 per serving)
iHerb
$ 43.95
Pure Formulas
$ 42.95
Report prices

Analysis

The two-capsule serving combines 600 mg of NAC, 375 mg of decaffeinated green tea extract, 250 mg of quercetin, 200 mg of vitamin C, and 30 mg of zinc glycinate. Those amounts provide meaningful antioxidant and immune nutrient depth.

Zinc form quality is strong, but no copper is included with the high daily zinc amount. Green tea catechin content is not standardized in the supplied data, so extract potency remains uncertain.

The focused formula suits short-term or targeted use better than indefinite daily supplementation. Premium serving cost is easier to justify for the full combination than for zinc or green tea alone.

Who is it for
  • Adults seeking NAC with zinc and quercetin
  • People wanting a decaffeinated antioxidant formula
  • Short-term targeted users
Best for
  • Antioxidant support
  • Immune nutrient coverage
  • NAC and quercetin combination

Pros

  • Substantial NAC amount
  • Uses zinc glycinate
  • Includes decaffeinated green tea and quercetin

Cons

  • No copper with 30 mg zinc
  • Green tea marker content is unspecified
  • High serving cost

Warnings

  • Long-term 30 mg zinc use without copper may reduce copper status
  • NAC may enhance nitrate-related headache or low blood pressure
  • Concentrated green tea extract may cause nausea and should be stopped if unusual abdominal pain or dark urine develops

Nutrient quality

84 Highest impact

Zinc glycinate, N-acetylcysteine, vitamin C, decaffeinated green tea, and quercetin are relevant and meaningfully dosed. High zinc and missing green-tea catechin standardization reduce long-term and potency confidence.

Ingredient transparency

81 Highest impact

Every active has a specific amount and no proprietary blend hides the doses. Green-tea catechin yield, complete directions, and inactive capsule ingredients are not supplied.

Customer satisfaction

65 Moderate impact

The aggregate rating is favorable and supported by a useful number of reviews. No specific review comments were supplied, so repeated complaints and purpose-related experiences cannot be verified.

Value for money

70 High impact

Meaningful doses and a focused active profile provide solid quality. The high recurring cost and lack of green-tea marker detail weaken category value.

Report analysis

Goals

General Health
General Health
Impact
Highest effect
A- Goal FitA Strength of SupportB CoverageA+ Formula Quality
Zinc · 30 mgVitamin C · 200 mg

Zinc, vitamin C, NAC, quercetin, and decaffeinated green tea form a logical antioxidant and immune-support combination. The formula offers meaningful targeted depth but does not cover the full range of foundational nutrients.

Zinc glycinate is a strong form, and every active amount is disclosed. The zinc amount is substantial and no copper is included, which limits prolonged daily use. Taking 30 mg of zinc daily for an extended period without copper may impair copper status, so long-term use should account for total zinc and copper intake.

Study evidence
Vitamin C Supportive 56 studies
Zinc Supportive 60 studies
Immunity
Immunity
Impact
Highest effect
A Goal FitB+ Strength of SupportB+ CoverageA Formula Quality
Vitamin C · 200 mgZinc · 30 mg

Zinc glycinate, NAC, vitamin C, quercetin, and green tea extract create a direct and focused immune-support formula. The zinc and NAC amounts are substantial, while vitamin C and quercetin provide complementary antioxidant support.

Green tea standardization is not stated, and vitamin C falls below the stronger target used here. Copper is also absent, which matters more if the 30 mg zinc amount is used daily for a long period.

Study evidence
Green Tea Not classified 2 studies
Vitamin C Supportive 53 studies
Zinc Supportive 73 studies
Anti-Inflammatory Support
Anti-Inflammatory Support
Impact
Highest effect
B+ Goal FitB Strength of SupportA- CoverageA Formula Quality
Vitamin C · 200 mgGreen Tea · 375 mg

N-acetylcysteine, quercetin, green tea extract, vitamin C, and zinc provide antioxidant, glutathione, cytokine, and immune-regulation support. The substantial N-acetylcysteine and quercetin amounts give the formula meaningful depth.

Green tea lacks an EGCG amount, preventing a precise potency assessment. Zinc at 30 mg without copper may create imbalance during prolonged daily use, so long-term intake deserves attention.

Study evidence
Green Tea Mixed 16 studies
Vitamin C Supportive 50 studies
Zinc Supportive 64 studies
Skin Health
Skin Health
Impact
Highest effect
B Goal FitB+ Strength of SupportB+ CoverageA Formula Quality
Zinc · 30 mgVitamin C · 200 mgGreen Tea · 375 mg

Zinc, vitamin C, NAC, green tea, and quercetin provide a coherent mix of repair and antioxidant support. Several actives are present at meaningful amounts rather than token levels.

Green tea catechin yield is not disclosed, and the formula lacks a structural or hydration active. The zinc amount may be unsuitable for prolonged daily use without a copper source.

Study evidence
Green Tea Supportive 37 studies
Vitamin C Supportive 53 studies
Zinc Supportive 66 studies
Anti-Aging
Anti-Aging
Impact
High effect
C+ Goal FitC+ Strength of SupportB CoverageA- Formula Quality
Green Tea · 375 mg

NAC, quercetin, vitamin C, and decaffeinated green tea create a coherent antioxidant-focused formula. Useful disclosed amounts support glutathione production and inflammatory balance, while zinc glycinate adds a well-absorbed mineral form.

The green tea extract does not state EGCG or catechin yield, so its contribution to targeted longevity pathways is uncertain. Daily use of the relatively high zinc amount without meaningful copper could gradually disturb copper balance.

Study evidence
Green Tea Supportive 9 studies
Vitamin C Supportive 30 studies
Zinc Supportive 10 studies
Vision Support
Vision Support
Impact
Moderate effect
D Goal FitB+ Strength of SupportD CoverageB- Formula Quality
Zinc · 30 mgVitamin C · 200 mg

Zinc glycinate and vitamin C provide two antioxidant nutrients relevant to ocular tissues. The immune-focused pair lacks macular pigments, vitamin E, copper, and DHA.

Both forms and amounts are clear, and zinc reaches a substantial level. Missing copper makes prolonged daily use less balanced at 30 mg zinc.

Study evidence
Vitamin C Disputed 24 studies
Zinc Supportive 39 studies

Ingredients

IngredientAmount per serving
Vitamin C (Ascorbic Acid)
 200 mg
Zinc (Zinc Glycinate)
 30 mg
N-Acetylcysteine
600 mg
Green Tea Leaf Extract, Decaffeinated (Camellia sinensis Leaf Extract, Decaffeinated)
 375 mg
Quercetin
250 mg
Gluten Free Adults 18–50
Report overview
Zinc (Zinc Glycinate) · 30 mg OverallScore80
A+ Active Ingredient Quality & BioavailabilityA- Dose, Safety & Label TransparencyF Value

The zinc glycinate source offers strong absorption potential, while the vegetarian capsule format is well suited to use. Its 30 mg elemental serving is clearly stated and fits the preferred effective range. Copper omission limits prolonged daily use, while value is weak because it costs well above the collection benchmark.

View ingredientView products
Green Tea (Camellia sinensis Leaf Extract, Decaffeinated) · 375 mg OverallScore28
F Active Ingredient Quality & BioavailabilityD- Dose, Safety & Label TransparencyF Value
Decaffeinated green tea and vitamin C support stimulant management and catechin stability. The extract amount is clear, but EGCG yield and active-marker standardization are not. Its practical dose and cost efficiency for green tea therefore remain uncertain.
View ingredientView products
Loading alternative details
84 Performance

EGCg Green Tea Extract

Protocol For Life Balance
<p>A more focused ingredient profile provides 400 mg of green tea extract with catechins and EGCG plus decaffeinated green tea. Compared with the original’s 30 mg zinc glycinate, decaffeinated green tea, vitamin C, NAC, and quercetin, it strengthens green-tea disclosure, but it does not replace the original zinc, vitamin C, NAC, or quercetin.</p>
85 Performance

Zinc Chelate 30 mg

Nature's Way
<p>A more focused ingredient profile provides 30 mg of zinc bisglycinate. Compared with the original’s 30 mg zinc glycinate, decaffeinated green tea, vitamin C, NAC, and quercetin, it offers focused zinc support, but it does not replace the original green tea, vitamin C, NAC, or quercetin.</p>
79 Performance

Decaffeinated Mega Green Tea Extract

Life Extension
<p>A more focused ingredient profile provides 725 mg of decaffeinated green tea extract with EGCG and polyphenols identified. Compared with the original’s 30 mg zinc glycinate, decaffeinated green tea, vitamin C, NAC, and quercetin, it strengthens green-tea disclosure, but it does not replace the original zinc, vitamin C, NAC, or quercetin.</p>
84 Budget

Zinc Gluconate 30 mg

Swanson
<p>A lower serving cost provides 30 mg of zinc gluconate. Compared with the original’s 30 mg zinc glycinate, decaffeinated green tea, vitamin C, NAC, and quercetin, it offers focused zinc support, but it does not replace the original green tea, vitamin C, NAC, or quercetin.</p>
85 Budget

Zinc 30 mg

Nature Made
<p>A lower serving cost provides 30 mg of zinc gluconate. Compared with the original’s 30 mg zinc glycinate, decaffeinated green tea, vitamin C, NAC, and quercetin, it offers focused zinc support, but it does not replace the original green tea, vitamin C, NAC, or quercetin.</p>
80 Budget

Green Tea

Jarrow Formulas
<p>A lower serving cost provides 500 mg of green tea extract with catechins, EGCG, and polyphenols identified. Compared with the original’s 30 mg zinc glycinate, decaffeinated green tea, vitamin C, NAC, and quercetin, it strengthens green-tea disclosure, but it does not replace the original zinc, vitamin C, NAC, or quercetin.</p>
84 Value

EGCg Green Tea Extract 400 mg

NOW
<p>A useful value balance provides 400 mg of green tea extract with EGCG and total catechins plus decaffeinated green tea. Compared with the original’s 30 mg zinc glycinate, decaffeinated green tea, vitamin C, NAC, and quercetin, it strengthens green-tea disclosure, but it does not replace the original zinc, vitamin C, NAC, or quercetin.</p>
87 Value

Zinc Picolinate 25 mg

Thompson
<p>A useful value balance provides 25 mg of zinc picolinate. Compared with the original’s 30 mg zinc glycinate, decaffeinated green tea, vitamin C, NAC, and quercetin, it offers focused zinc support, but it does not replace the original green tea, vitamin C, NAC, or quercetin.</p>
77 Value

Green Tea Extract

ZHOU
<p>A useful value balance provides 500 mg of green tea extract with catechins, EGCG, and polyphenols identified. Compared with the original’s 30 mg zinc glycinate, decaffeinated green tea, vitamin C, NAC, and quercetin, it strengthens green-tea disclosure, but it does not replace the original zinc, vitamin C, NAC, or quercetin.</p>
Report alternatives

Sources

Published studies used for the product analysis and the top-ranked studies for each ingredient and goal.

  1. Green tea and coffee intake and risk of cognitive decline in older adults: the National Institute for Longevity Sciences, Longitudinal Study of Aging.
    Shirai Y; Kuriki K; Otsuka R; Kato Y; Nishita Y; Tange C; Tomida M; Imai T; Ando F; Shimokata H · Public health nutrition · 2021
    Cohort study1,305 participantsAnti-Aging forGreen Tea
  2. Associations of green tea, coffee, and soft drink consumption with longitudinal changes in leukocyte telomere length.
    Sohn I; Shin C; Baik I · Scientific reports · 2023
    Cohort study1,952 participantsAnti-Aging forGreen Tea
  3. Can teatime increase one's lifetime?
    Nakachi K; Eguchi H; Imai K · Ageing research reviews · 2003
    Cohort studyAnti-Aging forGreen Tea
  4. Influences of tea consumption on self-rated health and life satisfaction among older adults: Evidence from the CLHLS.
    Zou M; Sun C; Yang M; Li C; Wang S; Zheng D; Wang J; Yu L; Sun L; Wang Y; Chen H; Zeng Y · PsyCh journal · 2025
    Cohort study78,345 participantsAnti-Aging forGreen Tea
  5. Double-blinded, placebo-controlled trial of green tea extracts in the clinical and histologic appearance of photoaging skin.
    Chiu AE; Chan JL; Kern DG; Kohler S; Rehmus WE; Kimball AB · Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.] · 2005
    Randomized trial40 participantsAnti-Aging forGreen Tea
  6. Study on the Multiple Efficacies of Vitamin C Serum in Anti-Glycation, Anti-Carbonylation, Antioxidation, and Anti-Inflammation of Human Skin Based on In Vivo Tests.
    Zi Y; Liu J; Liu Q; Pan Y; Jiang X · Journal of cosmetic dermatology · 2026
    Randomized trial66 participantsAnti-Aging forVitamin C
  7. Evaluation of the anti-wrinkle effect of a lipophilic pro-vitamin C derivative, tetra-isopalmitoyl ascorbic acid.
    Yokota M; Yahagi S · Journal of cosmetic dermatology · 2022
    Randomized trial69 participantsAnti-Aging forVitamin C
  8. The role of vitamin C in pushing back the boundaries of skin aging: an ultrasonographic approach.
    Crisan D; Roman I; Crisan M; Scharffetter-Kochanek K; Badea R · Clinical, cosmetic and investigational dermatology · 2015
    Clinical trial60 participantsAnti-Aging forVitamin C
  9. In vivo evaluation of topical ascorbic acid application on skin aging by 50 MHz ultrasound.
    Vergilio MM; Aiello LM; Furlan AS; Caritá AC; Azevedo JR; Bolzinger MA; Chevalier Y; Leonardi GR · Journal of cosmetic dermatology · 2022
    Randomized trial25 participantsAnti-Aging forVitamin C
  10. Clinical Applications of Vitamin C in Dermatology: A Systematic Review.
    Boghosian T; Mendez H; Boghosian N; Sayegh M; Beer J; Tosti A · The Journal of clinical and aesthetic dermatology · 2026
    Systematic review44 studies pooledAnti-Aging forVitamin C
  11. The Association between Dietary Nutrient Intake and Acceleration of Aging: Evidence from NHANES.
    Ma J; Li P; Jiang Y; Yang X; Luo Y; Tao L; Guo X; Gao B · Nutrients · 2024
    Cross-sectional study4,692 participantsAnti-Aging forZinc
  12. The immune system and the impact of zinc during aging.
    Haase H; Rink L · Immunity & ageing : I & A · 2010
    Narrative reviewAnti-Aging forZinc
  13. Associations between serum trace elements and biological age acceleration in the Chinese elderly: A community-based study investigating the mediating role of inflammatory markers and the moderating effect of physical activity.
    Wang Y; Zhu W; Zhang T; Liu Q; Zou M; Xie Y; Wang M; Wang TS; Pang Y; Jing T; Zhang R · Journal of hazardous materials · 2025
    Observational studyAnti-Aging forZinc
  14. Bidirectional associations of zinc supplement intake with biological ageing interacted by metabolic equivalent of task: A large-scale population-based Biobank study.
    Zhou Y; Zhou J; Li Z; Wang J; Li H; Yin X; Gao J; Wu Y; Li J; Sun YX; Li Y; Wang W; Eser PO; Assimes TL; He J; Chen G · Clinical nutrition (Edinburgh, Scotland) · 2025
    Cross-sectional study68,947 participantsAnti-Aging forZinc
  15. Zinc, metallothioneins, longevity: effect of zinc supplementation on antioxidant response: a Zincage study.
    Mocchegiani E; Zincage Consortium · Rejuvenation research · 2008
    Narrative reviewAnti-Aging forZinc
  16. The effects of green tea on acne vulgaris: A systematic review and meta-analysis of randomized clinical trials.
    Kim S; Park TH; Kim WI; Park S; Kim JH; Cho MK · Phytotherapy research : PTR · 2021
    Meta-analysis247 participants5 studies pooledAnti-Inflammatory Support forGreen Tea
  17. Green Tea Catechin Association with Ultraviolet Radiation-Induced Erythema: A Systematic Review and Meta-Analysis.
    Kapoor MP; Sugita M; Fukuzawa Y; Timm D; Ozeki M; Okubo T · Molecules (Basel, Switzerland) · 2021
    Meta-analysis100 participants6 studies pooledAnti-Inflammatory Support Skin Health forGreen Tea
  18. Efficacy of (-)-epigallocatechin gallate delivered by a new-type scaler tip during scaling and root planing on chronic periodontitis: a split-mouth, randomized clinical trial.
    Wang Y; Zeng J; Yuan Q; Luan Q · BMC oral health · 2021
    Randomized trial20 participantsAnti-Inflammatory Support forGreen Tea
  19. Camellia Sinensis Mouthwashes in Oral Care: a Systematic Review.
    Tafazoli A; Tafazoli Moghadam E · Journal of dentistry (Shiraz, Iran) · 2020
    Systematic review69 studies pooledAnti-Inflammatory Support forGreen Tea
  20. Skin photoprotection by green tea: antioxidant and immunomodulatory effects.
    Katiyar SK · Current drug targets. Immune, endocrine and metabolic disorders · 2004
    Narrative reviewAnti-Inflammatory Support forGreen Tea
  21. Efficacy of Vitamin C as Glucocorticoid Substitute for Reducing Pain and Inflammation After Total Hip Arthroplasty: A Randomized Controlled Trial.
    Jiang W; Xu H; Jiang X; Zhan Y; Ju Y; Xie J; Huang Z; Huang Q; Pei F · The Journal of bone and joint surgery. American volume · 2025
    Randomized trial107 participantsAnti-Inflammatory Support forVitamin C
  22. The Impact of Vitamin C on Analgesic, Anti-inflammatory, and Hemostatic Outcomes After Total Hip and Knee Arthroplasty: A Systematic Review and Meta-Analysis.
    Moftakhari Hajimirzaei S; Bagherzadeh Cham M; Dolikhani M; Tabatabaee SM; Ebrahimpour A · The archives of bone and joint surgery · 2026
    Meta-analysis1,162 participants10 studies pooledAnti-Inflammatory Support forVitamin C
  23. The impact of vitamin C supplementation on the perioperative outcomes after total hip and knee arthroplasty: a systematic review and meta-analysis.
    Liu X; Guo J; Li Y; Yang Y; Liu M; Gao Q; Yang Y; Wu X; Yue C · BMC musculoskeletal disorders · 2026
    Meta-analysis852 participants8 studies pooledAnti-Inflammatory Support forVitamin C
  24. Therapeutic Impact of Ascorbic Acid on Oral and Periodontal Tissues: A Systematic Literature Review.
    Ruzijevaite G; Acaite E; Jagelaviciene E · Medicina (Kaunas, Lithuania) · 2025
    Systematic review811 participants17 studies pooledAnti-Inflammatory Support forVitamin C
  25. Oral vitamin C administration reduces early recurrence rates after electrical cardioversion of persistent atrial fibrillation and attenuates associated inflammation.
    Korantzopoulos P; Kolettis TM; Kountouris E; Dimitroula V; Karanikis P; Pappa E; Siogas K; Goudevenos JA · International journal of cardiology · 2005
    Randomized trial44 participantsAnti-Inflammatory Support forVitamin C
  26. Zinc decreases C-reactive protein, lipid peroxidation, and inflammatory cytokines in elderly subjects: a potential implication of zinc as an atheroprotective agent.
    Bao B; Prasad AS; Beck FW; Fitzgerald JT; Snell D; Bao GW; Singh T; Cardozo LJ · The American journal of clinical nutrition · 2010
    Randomized trial40 participantsAnti-Inflammatory Support forZinc
  27. Zinc Supplementation in Individuals with Prediabetes and type 2 Diabetes: a GRADE-Assessed Systematic Review and Dose-Response Meta-analysis.
    Nazari M; Nikbaf-Shandiz M; Pashayee-Khamene F; Bagheri R; Goudarzi K; Hosseinnia NV; Dolatshahi S; Omran HS; Amirani N; Ashtary-Larky D; Asbaghi O; Ghanavati M · Biological trace element research · 2024
    Meta-analysis23 studies pooledAnti-Inflammatory Support forZinc
  28. The Effects of Zinc Supplementation on C-Reactive Protein and Inflammatory Cytokines: A Meta-Analysis and Systematical Review.
    Ceylan MN; Akdas S; Yazihan N · Journal of interferon & cytokine research : the official journal of the International Society for Interferon and Cytokine Research · 2022
    Meta-analysis73 studies pooledAnti-Inflammatory Support forZinc
  29. The Effects of Zinc Sulfate Supplementation on Serum Copeptin, C-Reactive Protein and Metabolic Markers in Zinc-Deficient Diabetic Patients on Hemodialysis: A Randomized, Double-Blind, Placebo-Controlled Trial.
    Hosseini R; Montazerifar F; Shahraki E; Karajibani M; Mokhtari AM; Dashipour AR; Ferns GA; Jalali M · Biological trace element research · 2021
    Randomized trial46 participantsAnti-Inflammatory Support forZinc
  30. Zinc supplementation and cardiovascular disease risk factors: A GRADE-assessed systematic review and dose-response meta-analysis.
    Nazari M; Ashtary-Larky D; Nikbaf-Shandiz M; Goudarzi K; Bagheri R; Dolatshahi S; Omran HS; Amirani N; Ghanavati M; Asbaghi O · Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS) · 2023
    Meta-analysis75 studies pooledAnti-Inflammatory Support forZinc
  31. Dietary intake and blood concentrations of antioxidants and the risk of cardiovascular disease, total cancer, and all-cause mortality: a systematic review and dose-response meta-analysis of prospective studies.
    Aune D; Keum N; Giovannucci E; Fadnes LT; Boffetta P; Greenwood DC; Tonstad S; Vatten LJ; Riboli E; Norat T · The American journal of clinical nutrition · 2019
    Meta-analysis69 studies pooledGeneral Health forVitamin C
  32. Scientific Opinion on the substantiation of a health claim related to vitamin C and increasing non haem iron absorption pursuant to Article 14 of Regulation (EC) No 1924/2006.
    EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) · EFSA journal. European Food Safety Authority · 2026
    Guideline / consensusGeneral Health forVitamin C
  33. Vitamin C Depletion and All-Cause Mortality in Renal Transplant Recipients.
    Sotomayor CG; Eisenga MF; Gomes Neto AW; Ozyilmaz A; Gans ROB; Jong WHA; Zelle DM; Berger SP; Gaillard CAJM; Navis GJ; Bakker SJ · Nutrients · 2018
    Cohort study598 participantsGeneral Health forVitamin C
  34. Associations of Serum Biomarkers of Fruit and Vegetable Intake With the Risk of Cause-Specific Mortality and All-Cause Mortality: A National Prospective Cohort Study.
    Pu L; Zhang R; Wang X; Zhao T; Sun H; Han L · Frontiers in nutrition · 2022
    Cohort study12,530 participantsGeneral Health forVitamin C
  35. Relation between plasma ascorbic acid and mortality in men and women in EPIC-Norfolk prospective study: a prospective population study. European Prospective Investigation into Cancer and Nutrition.
    Khaw KT; Bingham S; Welch A; Luben R; Wareham N; Oakes S; Day N · Lancet (London, England) · 2001
    Cohort study19,496 participantsGeneral Health forVitamin C
  36. Effectiveness of sodium bicarbonate and zinc chloride mouthwashes in the treatment of oral mucositis and quality of life in patients with cancer under chemotherapy.
    Mohammadi F; Oshvandi K; Kamallan SR; Khazaei S; Ranjbar H; Ahmadi-Motamayel F; Gillespie M; Jenabi E; Vafaei SY · Nursing open · 2022
    Randomized trial144 participantsGeneral Health forZinc
  37. Zinc supplementation in young children with acute diarrhea in India.
    Sazawal S; Black RE; Bhan MK; Bhandari N; Sinha A; Jalla S · The New England journal of medicine · 1995
    Randomized trial937 participantsGeneral Health forZinc
  38. Associations of mortality with ocular disorders and an intervention of high-dose antioxidants and zinc in the Age-Related Eye Disease Study: AREDS Report No. 13.
    Clemons TE; Kurinij N; Sperduto RD; AREDS Research Group · Archives of ophthalmology (Chicago, Ill. : 1960) · 2004
    Randomized trial4,753 participantsGeneral Health forZinc
  39. Effects of zinc and probiotic co-supplementation on inflammation, gastrointestinal symptoms, quality of life, and mood in irritable bowel syndrome patients.
    Rezazadegan M; Soheilipour M; Amani R · Scientific reports · 2026
    Randomized trial84 participantsGeneral Health forZinc
  40. Effect of zinc sulfate supplementation on premenstrual syndrome and health-related quality of life: Clinical randomized controlled trial.
    Siahbazi S; Behboudi-Gandevani S; Moghaddam-Banaem L; Montazeri A · The journal of obstetrics and gynaecology research · 2018
    Randomized trial142 participantsGeneral Health forZinc
  41. Management of hair loss associated with endocrine therapy in patients with breast cancer: an overview.
    Karatas F; Sahin S; Sever AR; Altundag K · SpringerPlus · 2016
    Narrative reviewHair Health forVitamin C
  42. Elucidating causal relationships of diet-derived circulating antioxidants and the risk of non-scarring alopecia: A Mendelian randomization study.
    Ba Y; Shen L; Peng X; Zhang Y; Wang J · Medicine · 2024
    Methods validation study201,019 participantsHair Health forVitamin C
  43. Alterations of plasma antioxidants and mitochondrial DNA mutation in hair follicles of smokers.
    Liu CS; Chen HW; Lii CK; Tsai CS; Kuo CL; Wei YH · Environmental and molecular mutagenesis · 2002
    Observational studyHair Health forVitamin C
  44. Removal of synthetic hair dye using formamidine sulfinic acid and other sulfinate precursors.
    Hawkes JA; Lewis DM; Mama J; Murray J · International journal of cosmetic science · 2026
    Methods validation studyHair Health forVitamin C
  45. A Zinc Sulphate-Resistant Acrodermatitis Enteropathica Patient with a Novel Mutation in SLC39A4 Gene.
    Kilic M; Taskesen M; Coskun T; Gürakan F; Tokatli A; Sivri HS; Dursun A; Schmitt S; Küry S · JIMD reports · 2013
    Case reportHair Health forVitamin C
  46. The effects of minoxidil, 1% pyrithione zinc and a combination of both on hair density: a randomized controlled trial.
    Berger RS; Fu JL; Smiles KA; Turner CB; Schnell BM; Werchowski KM; Lammers KM · The British journal of dermatology · 2003
    Randomized trial200 participantsHair Health forZinc
  47. Incubatory environment of the scalp impacts pre-emergent hair to affect post-emergent hair cuticle integrity.
    Schwartz JR; Henry JP; Kerr KM; Flagler MJ; Page SH; Redman-Furey N · Journal of cosmetic dermatology · 2018
    Randomized trialHair Health forZinc
  48. A comparison of hair quality and cosmetic acceptance following the use of two anti-dandruff shampoos.
    Draelos ZD; Kenneally DC; Hodges LT; Billhimer W; Copas M; Margraf C · The journal of investigative dermatology. Symposium proceedings · 2006
    Randomized trial40 participantsHair Health forZinc
  49. BMI and levels of zinc, copper in hair, serum and urine of Turkish male patients with androgenetic alopecia.
    Ozturk P; Kurutas E; Ataseven A; Dokur N; Gumusalan Y; Gorur A; Tamer L; Inaloz S · Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS) · 2015
    Case-control study216 participantsHair Health forZinc
  50. Analysis of serum zinc and copper concentrations in hair loss.
    Kil MS; Kim CW; Kim SS · Annals of dermatology · 2013
    Case-control study342 participantsHair Health forZinc
  51. Preventive effects of tea and tea catechins against influenza and acute upper respiratory tract infections: a systematic review and meta-analysis
    Mai Umeda, Takeichiro Tominaga, Kazuya Kozuma, Hidefumi Kitazawa, Daisuke Furushima, Masanobu Hibi, Hiroshi Yamada · European Journal of Nutrition · 2021
    Meta-analysis3,748 participants10 studies pooledImmunity forGreen Tea
  52. Prevention of Acute Upper Respiratory Infections by Consumption of Catechins in Healthcare Workers: A Randomized, Placebo-Controlled Trial
    Daisuke Furushima, Takuma Nishimura, Norikata Takuma, Ryo Iketani, Tomohito Mizuno, Yuji Matsui, Tohru Yamaguchi, Yu Nakashima, Shinji Yamamoto, Masanobu Hibi, Hiroshi Yamada · Nutrients · 2019
    Randomized trial255 participantsImmunity forGreen Tea
  53. Vitamin C and contribution to the normal function of the immune system: evaluation of a health claim pursuant to Article 14 of Regulation (EC) No 1924/2006.
    EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) · EFSA journal. European Food Safety Authority · 2026
    Guideline / consensusImmunity forVitamin C
  54. Therapeutic effects of high-dose vitamin C supplementation in patients with COVID-19: a meta-analysis.
    Sun L; Zhao JH; Fan WY; Feng B; Liu WW; Chen RQ; Ban C; Dang AG; Wang M; Luo KT; Zhou GY; Yu FF; Ba Y · Nutrition reviews · 2024
    Meta-analysis2,334 participants14 studies pooledImmunity forVitamin C
  55. Effect of micronutrient supplements on influenza and other respiratory tract infections among adults: a systematic review and meta-analysis.
    Abioye AI; Bromage S; Fawzi W · BMJ global health · 2021
    Meta-analysisImmunity forVitamin C
  56. New evidence for antioxidant properties of vitamin C.
    Vojdani A; Bazargan M; Vojdani E; Wright J · Cancer detection and prevention · 2001
    Randomized trial20 participantsImmunity forVitamin C
  57. Enhanced Vitamin C Delivery: A Systematic Literature Review Assessing the Efficacy and Safety of Alternative Supplement Forms in Healthy Adults.
    Calder PC; Kreider RB; McKay DL · Nutrients · 2025
    Systematic review13 studies pooledImmunity forVitamin C
  58. Nutrient supplementation for prevention of viral respiratory tract infections in healthy subjects: A systematic review and meta-analysis.
    Vlieg-Boerstra B; de Jong N; Meyer R; Agostoni C; De Cosmi V; Grimshaw K; Milani GP; Muraro A; Oude Elberink H; Pali-Schöll I; Roduit C; Sasaki M; Skypala I; Sokolowska M; van Splunter M; Untersmayr E; Venter C; O'Mahony L; Nwaru BI · Allergy · 2022
    Meta-analysis199,055 participants115 studies pooledImmunity forZinc
  59. Zinc supplementation reduces the incidence of acute lower respiratory infections in infants and preschool children: a double-blind, controlled trial.
    Sazawal S; Black RE; Jalla S; Mazumdar S; Sinha A; Bhan MK · Pediatrics · 1998
    Randomized trial609 participantsImmunity forZinc
  60. A randomized controlled trial of zinc supplementation in the treatment of acute respiratory tract infection in Thai children.
    Rerksuppaphol S; Rerksuppaphol L · Pediatric reports · 2020
    Randomized trial64 participantsImmunity forZinc
  61. The effect of zinc and vitamin A supplementation on immune response in an older population.
    Fortes C; Forastiere F; Agabiti N; Fano V; Pacifici R; Virgili F; Piras G; Guidi L; Bartoloni C; Tricerri A; Zuccaro P; Ebrahim S; Perucci CA · Journal of the American Geriatrics Society · 1998
    Randomized trial136 participantsImmunity forZinc
  62. The role of specific nutrients in preventing immune system and blood cell disorders: an umbrella review.
    Vecchietti A; Strano P; Minutolo G; Grieco V; Cappuccio G; Granvillano G; Confalonieri L; Briganti GL; Raso E; Chimienti M; Pellegrini M; Mercogliano M; Spatari G; Lugli C; Urbano T; Lorenzon A · Journal of preventive medicine and hygiene · 2026
    Systematic review13 studies pooledImmunity forZinc
  63. Topical Polyphenon E in the treatment of external genital and perianal warts: a randomized controlled trial.
    Stockfleth E; Beti H; Orasan R; Grigorian F; Mescheder A; Tawfik H; Thielert C · The British journal of dermatology · 2008
    Randomized trial503 participantsSkin Health forGreen Tea
  64. Efficacy, safety and tolerability of green tea catechins in the treatment of external anogenital warts: a systematic review and meta-analysis.
    Tzellos TG; Sardeli C; Lallas A; Papazisis G; Chourdakis M; Kouvelas D · Journal of the European Academy of Dermatology and Venereology : JEADV · 2011
    Meta-analysis1,247 participants3 studies pooledSkin Health forGreen Tea
  65. Green tea polyphenols provide photoprotection, increase microcirculation, and modulate skin properties of women.
    Heinrich U; Moore CE; De Spirt S; Tronnier H; Stahl W · The Journal of nutrition · 2011
    Randomized trial60 participantsSkin Health forGreen Tea
  66. Efficacy of Epigallocatechin-3-Gallate in Preventing Dermatitis in Patients With Breast Cancer Receiving Postoperative Radiotherapy: A Double-Blind, Placebo-Controlled, Phase 2 Randomized Clinical Trial.
    Zhao H; Zhu W; Zhao X; Li X; Zhou Z; Zheng M; Meng X; Kong L; Zhang S; He D; Xing L; Yu J · JAMA dermatology · 2022
    Randomized trial180 participantsSkin Health forGreen Tea
  67. Evaluation of the anti-wrinkle effect of an ascorbic acid-loaded dissolving microneedle patch via a double-blind, placebo-controlled clinical study.
    Lee C; Yang H; Kim S; Kim M; Kang H; Kim N; An S; Koh J; Jung H · International journal of cosmetic science · 2017
    Randomized trial23 participantsSkin Health forVitamin C
  68. Comparative Study on the Outcome of Periorbital Wrinkles Treated with Laser-Assisted Delivery of Vitamin C or Vitamin C Plus Growth Factors: A Randomized, Double-blind, Clinical Trial.
    Machado BHB; Frame J; Zhang J; Najlah M · Aesthetic plastic surgery · 2021
    Randomized trial149 participantsSkin Health forVitamin C
  69. Randomized trial of topical ascorbic acid in DMSO versus imiquimod for the treatment of basal cell carcinoma.
    Burke B; Bailie JE · Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie · 2022
    Randomized trial25 participantsSkin Health forVitamin C
  70. Vitamin C improves healing of foot ulcers: a randomised, double-blind, placebo-controlled trial.
    Gunton JE; Girgis CM; Lau T; Vicaretti M; Begg L; Flood V · The British journal of nutrition · 2022
    Randomized trial16 participantsSkin Health forVitamin C
  71. Dietary nutrient intakes and skin-aging appearance among middle-aged American women.
    Cosgrove MC; Franco OH; Granger SP; Murray PG; Mayes AE · The American journal of clinical nutrition · 2007
    Cross-sectional study4,025 participantsSkin Health forVitamin C
  72. Sex-related differences in response to zinc pyrithione shampoo vs. non-anti-dandruff shampoo.
    Collins LZ; Baines FL; Matheson JR; Turner GA; Diao Y; Li Y; Pi Y · International journal of cosmetic science · 2019
    Meta-analysis2,088 participants20 studies pooledSkin Health forZinc
  73. Maintenance of an Acidic Skin Surface with a Novel Zinc Lactobionate Emollient Preparation Improves Skin Barrier Function in Patients with Atopic Dermatitis.
    Andrew PV; Pinnock A; Poyner A; Brown K; Chittock J; Kay LJ; Cork MJ; Danby SG · Dermatology and therapy · 2024
    Cohort study23 participantsSkin Health forZinc
  74. Spatial expression of metallothionein, matrix metalloproteinase-1 and Ki-67 in human epidermal wounds treated with zinc and determined by quantitative immunohistochemistry: A randomised double-blind trial.
    Ågren MS; Chafranska L; Eriksen JO; Forman JL; Bjerrum MJ; Schjerling P; Larsen HF; Cottarelli E; Jorgensen LN; Gjerdrum LMR · European journal of cell biology · 2021
    Randomized trial30 participantsSkin Health forZinc
  75. A pilot trial using topical regular crystalline insulin vs. aqueous zinc solution for uncomplicated cutaneous wound healing: Impact on quality of life.
    Attia EA; Belal DM; El Samahy MH; El Hamamsy MH · Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society · 2014
    Randomized trial90 participantsSkin Health forZinc
  76. Evidence-Based Nutritional Interventions in Wound Care.
    Saeg F; Orazi R; Bowers GM; Janis JE · Plastic and reconstructive surgery · 2021
    Systematic review2,339 participants36 studies pooledSkin Health forZinc
  77. Environmental exposure to metals and male reproductive hormones: circulating testosterone is inversely associated with blood molybdenum.
    Meeker JD; Rossano MG; Protas B; Padmanahban V; Diamond MP; Puscheck E; Daly D; Paneth N; Wirth JJ · Fertility and sterility · 2010
    Cross-sectional study219 participantsTestosterone Support forZinc
  78. Nonpharmacological Interventions for the Management of Testosterone and Sperm Parameters: A Scoping Review.
    Santos HO; Cadegiani FA; Forbes SC · Clinical therapeutics · 2022
    Scoping reviewTestosterone Support forZinc
  79. Zinc is an Essential Element for Male Fertility: A Review of Zn Roles in Men's Health, Germination, Sperm Quality, and Fertilization.
    Fallah A; Mohammad-Hasani A; Colagar AH · Journal of reproduction & infertility · 2020
    Narrative reviewTestosterone Support forZinc
  80. Clinical, endocrinological and biochemical effects of zinc deficiency.
    Prasad AS · Clinics in endocrinology and metabolism · 1986
    Narrative reviewTestosterone Support forZinc
  81. Clinical, endocrinologic, and biochemical effects of zinc deficiency.
    Prasad AS · Special topics in endocrinology and metabolism · 1986
    Narrative reviewTestosterone Support forZinc
  82. Role of Oral Vitamin 'C' on Astigmatic Errors in Phacoemulsification.
    Mohan S; Sah K; Khattri M; Ahmad L; Sachan SK · Current eye research · 2021
    Randomized trial400 participantsVision Support forVitamin C
  83. Ascorbic acid metabolites are involved in intraocular pressure control in the general population.
    Hysi PG; Khawaja AP; Menni C; Tamraz B; Wareham N; Khaw KT; Foster PJ; Benet LZ; Spector TD; Hammond CJ · Redox biology · 2019
    Observational studyVision Support forVitamin C
  84. Nutritional modulation of cataract.
    Weikel KA; Garber C; Baburins A; Taylor A · Nutrition reviews · 2014
    Narrative reviewVision Support forVitamin C
  85. Dietary n-3 Fatty Acid, α-Tocopherol, Zinc, vitamin D, vitamin C, and β-carotene are Associated with Age-Related Macular Degeneration in Japan.
    Aoki A; Inoue M; Nguyen E; Obata R; Kadonosono K; Shinkai S; Hashimoto H; Sasaki S; Yanagi Y · Scientific reports · 2017
    Case-control study530 participantsVision Support forVitamin C
  86. Adherence to a Mediterranean diet, lifestyle and age-related macular degeneration: the Coimbra Eye Study - report 3.
    Raimundo M; Mira F; Cachulo MDL; Barreto P; Ribeiro L; Farinha C; Laíns I; Nunes S; Alves D; Figueira J; Merle BM; Delcourt C; Santos L; Silva R · Acta ophthalmologica · 2019
    Case-control study883 participantsVision Support forVitamin C
  87. Antioxidant vitamin and mineral supplements for age-related macular degeneration.
    Evans JR · The Cochrane database of systematic reviews · 2002
    Systematic review170 participants7 studies pooledVision Support forZinc
  88. Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration.
    Evans JR; Lawrenson JG · The Cochrane database of systematic reviews · 2023
    Meta-analysis3,790 participants5 studies pooledVision Support forZinc
  89. Oral zinc in macular degeneration.
    Newsome DA; Swartz M; Leone NC; Elston RC; Miller E · Archives of ophthalmology (Chicago, Ill. : 1960) · 1988
    Randomized trial151 participantsVision Support forZinc
  90. A randomized, placebo-controlled, clinical trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age-related macular degeneration and vision loss: AREDS report no. 8.
    Age-Related Eye Disease Study Research Group · Archives of ophthalmology (Chicago, Ill. : 1960) · 2001
    Randomized trial3,640 participantsVision Support forZinc
  91. Effect of vitamin A and zinc supplementation on the nutriture of children in Northeast Thailand.
    Udomkesmalee E; Dhanamitta S; Sirisinha S; Charoenkiatkul S; Tuntipopipat S; Banjong O; Rojroongwasinkul N; Kramer TR; Smith JC · The American journal of clinical nutrition · 1992
    Randomized trial133 participantsVision Support forZinc