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Krebs Zinc

4.9
★ ★ ★ ★ ★
(755 ratings)
Zinc 30 mg
Product Image
Score72
The 30 mg amount is substantial and easy to use, but the exact zinc compounds are hidden behind a Krebs complex. Lack of copper also reduces its appeal for prolonged daily use.
How scoring works
Capsule
Quantity:60 Capsule(s) • (60 servings)
Goals:
Immunity
Testosterone Support
Vision Support
General Health
Skin Health
Hair Health

Score 72

The 30 mg amount is substantial and easy to use, but the exact zinc compounds are hidden behind a Krebs complex. Lack of copper also reduces its appeal for prolonged daily use.
How scoring works
$14.97($0.24 per serving)
iHerb
$ 15.75
Vitacost
$ 14.97
Daily Vita
$ 15.75
Report prices

Analysis

The capsule provides 30 mg of elemental zinc from a Krebs cycle complex. That is a meaningful amount, but the label does not identify the individual zinc compounds that make up the complex.

Zinc has direct relevance when dietary intake is inadequate, particularly for normal immune, tissue, and reproductive functions. A zinc-only approach still leaves most broader health pathways uncovered and may provide little extra value when status is already sufficient.

The capsule serving is simple, though the cost is higher than many basic zinc products. Ongoing use deserves attention to zinc from food and other supplements because no copper is present.

Who is it for
  • Adults seeking a robust but sub-upper-limit zinc amount
  • Users comfortable with an incompletely specified mineral complex
  • People monitoring total zinc and copper intake
Best for
  • Focused 30 mg zinc support
  • A one-capsule routine
  • Short-to-medium-term use when zinc intake is low

Pros

  • Clearly states 30 mg of elemental zinc
  • Remains below the usual adult upper intake level
  • Uses a convenient capsule
  • Provides focused single-mineral support

Cons

  • Does not identify the zinc compounds in the complex
  • No copper is included
  • Offers little broader nutrient coverage
  • Costs more than many simple zinc products

Warnings

  • Prolonged daily use of 30 mg zinc may impair copper balance, especially when combined with other zinc sources.
  • Zinc can reduce absorption of tetracycline or quinolone antibiotics and penicillamine; follow the prescribed separation interval.

Nutrient quality

72 High impact

The branded Krebs complex does not identify the zinc salts, limiting absorption assessment. The dose is useful, but the unknown salts and missing copper reduce confidence in long-term use.

Ingredient transparency

77 High impact

The elemental amount and total complex weight are stated. No proprietary blend hides the listed active doses.

Customer satisfaction

72 High impact

The supplied average is exceptionally strong, with moderate response volume. Complaint patterns and purpose-related experiences are not supplied.

Value for money

67 High impact

The asking price is only partly justified by the disclosed formula. Serving value is moderate relative to the formula quality.

Report analysis

Goals

Immunity
Immunity
Impact
Highest effect
A Goal FitB Strength of SupportC CoverageA- Formula Quality
Zinc · 30 mg

Zinc directly supports immune-cell development and communication, giving the formula a strong immunity rationale. The daily amount is robust and clearly disclosed.

The missing zinc compound prevents a reliable judgment of absorption quality. Prolonged use of the high zinc amount without copper may disrupt mineral balance, so total intake matters.

Study evidence
Zinc Supportive 73 studies
Testosterone Support
Testosterone Support
Impact
High effect
B+ Goal FitB- Strength of SupportD CoverageA Formula Quality
Zinc · 30 mg

Zinc directly supports steroidogenesis and testosterone status when intake is inadequate. The 30 mg amount is robust and remains within the usual adult upper limit.

The label does not identify the zinc compounds within the Krebs cycle complex, so absorption quality is uncertain. No copper is included, making prolonged daily use worth monitoring for total zinc and copper balance.

Study evidence
Zinc Disputed 7 studies
Vision Support
Vision Support
Impact
High effect
B+ Goal FitB+ Strength of SupportD+ CoverageB- Formula Quality
Zinc · 30 mg

Zinc supports retinal enzymes, vitamin A transport, and protective pigment production. The disclosed amount is meaningful and comes from an organic-acid complex intended to improve mineral delivery.

The exact component forms within the Krebs complex are not stated, and the formula lacks copper for long-term zinc balance. No lutein, zeaxanthin, vitamins C and E, omega-3 fats, or other major eye-support pathways are included.

Study evidence
Zinc Supportive 39 studies
General Health
General Health
Impact
High effect
A- Goal FitB- Strength of SupportC- CoverageB Formula Quality
Zinc · 30 mg

Zinc is a foundational nutrient with clear relevance to immune readiness, antioxidant defenses, and normal enzyme function. The disclosed amount is substantial enough to contribute meaningfully when zinc intake is inadequate.

The specific zinc compound is not identified, so absorption quality cannot be judged well. Regular long-term use also deserves attention to total zinc intake because no copper is included.

Study evidence
Zinc Supportive 60 studies
Skin Health
Skin Health
Impact
High effect
B- Goal FitB Strength of SupportD+ CoverageA- Formula Quality
Zinc · 30 mg

Zinc supports normal skin repair, immune defense, and inflammatory control, especially when zinc status is low. A mineral-only approach does not address collagen structure, hydration lipids, or photoprotection.

The 30 mg amount is meaningful, and the zinc compound is not identified beyond a Krebs complex. Prolonged daily use still warrants attention to total zinc and copper balance.

Study evidence
Zinc Supportive 66 studies
Hair Health
Hair Health
Impact
High effect
B+ Goal FitB Strength of SupportD- CoverageC Formula Quality
Zinc · 30 mg

A robust zinc dose may support follicle cell division and reduce deficiency-related shedding when zinc status is low. It does not address other hair pathways, and benefits are uncertain when zinc intake is already adequate.

The elemental amount is clear, but the exact zinc compounds in the Krebs complex are not identified. No copper is included, so prolonged daily use of 30 mg zinc may impair copper balance.

Study evidence
Zinc Supportive 22 studies

Ingredients

IngredientAmount per serving
Zinc
30 mg
Krebs Cycle 30% Zinc Complex
100 mg
Gluten Free Adults 18–50
Report overview
Zinc · 30 mg OverallScore55
F Active Ingredient Quality & BioavailabilityA- Dose, Safety & Label TransparencyC Value

The 30 mg zinc serving provides a robust daily amount within the usual upper limit. The missing zinc compound prevents a reliable judgment of absorption quality despite a disclosed dose. No copper is included, so prolonged daily use deserves attention to total zinc and copper intake.

View ingredientView products
Loading alternative details
87 Performance

Zinc Picolinate 22 mg

Solgar
The focused 22 mg zinc picolinate formula offers strong absorption and a more practical maintenance amount than the original's incompletely identified zinc form. Its clear single-active label also removes the uncertainty created by unnecessary or opaque additions.
87 Performance

Zinc Picolinate 25 mg

Thompson
A clearly disclosed 25 mg zinc picolinate dose is easier to use routinely than the original's incompletely identified zinc form. The simple formula combines favorable absorption with an amount below the usual adult upper limit.
86 Performance

L-OptiZinc 30 mg

NOW
L-OptiZinc monomethionine provides a specific, well-absorbed form that improves on the original's incompletely identified zinc form. The small copper addition offers some balance, although it may not fully offset sustained intake of 30 mg zinc.
84 Budget

Zinc Gluconate 30 mg

Swanson
Its lower recurring cost improves the value comparison, while 30 mg zinc gluconate reduces the dosing concern compared with the original's incompletely identified zinc form. The form and amount are clearly stated, though sustained use still calls for attention to copper intake.
85 Budget

Zinc 30 mg

Nature Made
Its lower recurring cost improves the value comparison, and the focused 30 mg zinc gluconate tablet avoids the extra or opaque ingredients in the original's incompletely identified zinc form. The amount remains substantial without reaching the common 50 mg excess seen in many originals.
85 Budget

Zinc Chelate 30 mg

Nature's Way
Its lower recurring cost improves the value comparison, while 30 mg zinc bisglycinate provides a well-absorbed chelate with a simpler profile than the original's incompletely identified zinc form. No copper is included, so prolonged daily use still deserves caution.
85 Value

Chelated Zinc 30 mg

Swanson
TRAACS zinc glycinate supplies a specific 30 mg chelate with strong absorption potential, giving better quality for the cost than the original's incompletely identified zinc form. The capsule stays focused and economical, although it does not include copper.
86 Value

Chelated Zinc 30 mg

Carlson
A 30 mg zinc glycinate chelate combines favorable absorption and digestive tolerance with strong serving value compared with the original's incompletely identified zinc form. The long supply supports economical use, but ongoing intake may still reduce copper status.
83 Value

Zinc 30 mg

Nature's Life
Zinc picolinate plus copper offers a more complete mineral-balance approach for the cost than the original's incompletely identified zinc form. The copper addition is useful, although repeated copper entries make the exact total less clear than it should be.
Report alternatives

Sources

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

  1. 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
  2. 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
  3. Zinc for infection prevention in children with sickle cell anemia: a randomized double-blind placebo-controlled trial.
    Namazzi R; Opoka R; Conroy AL; Datta D; Tagoola A; Bond C; Goings MJ; Ryu MS; Cusick SE; Krebs NF; Jang JH; Tu W; Ware RE; John CC · Blood advances · 2023
    Randomized trial252 participantsImmunity forZinc
  4. 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
  5. 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
  6. 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
  7. 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
  8. 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
  9. 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
  10. 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
  11. 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
  12. 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
  13. 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
  14. 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
  15. 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
  16. 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
  17. 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
  18. 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
  19. 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
  20. 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
  21. 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
  22. 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
  23. 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
  24. 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
  25. Clinical, endocrinological and biochemical effects of zinc deficiency.
    Prasad AS · Clinics in endocrinology and metabolism · 1986
    Narrative reviewTestosterone Support forZinc
  26. Clinical, endocrinologic, and biochemical effects of zinc deficiency.
    Prasad AS · Special topics in endocrinology and metabolism · 1986
    Narrative reviewTestosterone Support forZinc
  27. 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
  28. 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
  29. 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
  30. 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
  31. 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