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Ultra Potent-C 1000

4.7
★ ★ ★ ★ ★
(109 ratings)
Vitamin C 1000 mg
Niacin 70 mg
Product Image
Score66
Convenient high-dose vitamin C is undermined by unclear forms and several token-dose supporting ingredients.
How scoring works
Tablet
Quantity:90 Tablet(s) • (90 servings)
Goals:
Immunity
General Health
Anti-Inflammatory Support
Skin Health

Score 66

Convenient high-dose vitamin C is undermined by unclear forms and several token-dose supporting ingredients.
How scoring works
$39.95($0.44 per serving)
iHerb
$ 39.95
Pure Formulas
$ 39.95
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Analysis

The single tablet provides 1,000 mg of vitamin C for antioxidant, collagen, and immune-related support. Lysine, bioflavonoids, cysteine, and glutathione broaden the label, but their small amounts are unlikely to add much practical depth.

The label does not identify the vitamin C form or whether it is buffered. Niacin is also unspecified at 70 mg, making it impossible to tell whether flushing is likely, while the additional phosphate, ribose, and xylitol ingredients add complexity.

The once-daily format is convenient, but value is modest for what is mainly a high-dose vitamin C tablet. A simpler product with disclosed forms would be easier to evaluate for both tolerance and value.

Who is it for
  • Adults wanting a once-daily high-dose vitamin C tablet
  • People seeking basic antioxidant support
  • Users who tolerate larger vitamin C amounts
Best for
  • Vitamin C delivery
  • Single-tablet convenience
  • Basic antioxidant support

Pros

  • Provides 1,000 mg of vitamin C
  • Requires only one tablet per serving
  • Includes citrus bioflavonoids
  • Adds small amounts of cysteine and glutathione

Cons

  • Does not disclose the vitamin C form
  • Does not identify the niacin form
  • Most supporting ingredients are present in small amounts
  • Value is limited for a mostly single-nutrient formula

Warnings

  • The 70 mg niacin amount may cause flushing if it is nicotinic acid
  • The 1,000 mg vitamin C amount may cause loose stools or stomach upset
  • Xylitol may cause digestive discomfort in sensitive users

Nutrient quality

72 High impact

Vitamin C is supplied at a meaningful amount and the overall profile avoids an obvious extreme. Many forms are unspecified, while several supporting ingredients are present only in small amounts.

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Ingredient transparency

70 High impact

All named actives have amounts and the small citrus complex is the only partially grouped component. Missing forms, usage directions, and non-active ingredients reduce practical clarity.

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Customer satisfaction

63 Moderate impact

The listed average rating is strong, but the review count is comparatively modest. No detailed feedback is supplied to assess repeated issues or experiences tied to the intended use.

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Value for money

53 Moderate impact

The core vitamin C dose is meaningful, but many extras are too small to add clear value. The formula appears less competitive when compared with simpler, fully specified vitamin C options.

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Report analysis

Goals

Immunity
Immunity
Impact
High effect
A- Goal FitB Strength of SupportC CoverageD+ Formula Quality
Vitamin C · 1000 mg

A large vitamin C amount directly supports antioxidant protection and normal immune-cell function. The single-tablet format provides a clear and useful dose for this goal.

The vitamin C form and buffering status are not disclosed. High niacin and several tiny secondary ingredients add complexity without clearly improving immune support.

Study evidence
Vitamin C Supportive 53 studies
General Health
General Health
Impact
High effect
B+ Goal FitB- Strength of SupportC+ CoverageD+ Formula Quality
Vitamin C · 1000 mg

Vitamin C provides foundational antioxidant, immune, and collagen support. Vitamin C has established nutritional evidence, while the many minor companion ingredients add less certain value.

The 1,000 mg vitamin C amount is substantial, but most supporting actives are small and the niacin amount is unusually high. The label omits the vitamin C and niacin forms, limiting absorption and tolerance assessment. The 70 mg niacin amount may cause flushing if it is nicotinic acid, but the undisclosed form makes that risk hard to judge.

Study evidence
Vitamin C Supportive 56 studies
Anti-Inflammatory Support
Cellular Defense
Anti-Inflammatory Support
Impact
Moderate effect
C+ Goal FitB- Strength of SupportC CoverageD Formula Quality
Vitamin C · 1000 mg

Vitamin C at 1000 mg provides a substantial antioxidant dose that can limit oxidative damage associated with inflammation. Glutathione and cysteine are present at amounts too small to add meaningful pathway depth.

The vitamin C form and buffering status are not disclosed, and several minor additions clutter an otherwise focused product. Niacin at 70 mg may cause flushing if supplied as nicotinic acid, but its form is also unspecified.

Study evidence
Vitamin C Supportive 50 studies
Skin Health
Skin Health
Impact
Moderate effect
C Goal FitD Strength of SupportC CoverageC Formula Quality
Vitamin C · 1000 mgGluthathione · 5 mg

Niacin and Vitamin C provide a useful but incomplete connection to skin health. The supplied amounts do not establish strong targeted support.

Coverage reaches collagen synthesis and oxidative defense. The unspecified niacin form leaves open a risk of flushing at the disclosed amount.

Study evidence
Niacin Supportive 61 studies
Vitamin C Supportive 53 studies

Ingredients

IngredientAmount per serving
Vitamin C
1000 mg
Niacin
70 mg
Calcium
40 mg
Sodium
10 mg
L-Lysine
33 mg
Citrus Bioflavonoid Complex
32 mg
Tetrasodium Pyrophosphate
14 mg
Alpha D-Ribofuranose
13 mg
Xylitol
9 mg
L-Cysteine
8 mg
L-Glutathione
5 mg
Gluten Free Adults 18–50 Vegetarian
Report overview
Vitamin C · 1000 mg OverallScore52
F Active Ingredient Quality & BioavailabilityB+ Dose, Safety & Label TransparencyF Value

The tablet provides a well-targeted dose, but the vitamin C form and buffering status are not disclosed. Minor sugar alcohol and phosphate additives are not major fillers, yet they keep the formula from being especially clean. Its high niacin amount may cause flushing if supplied as nicotinic acid, but the niacin form is also unspecified.

View ingredientView products
Niacin · 70 mg OverallScore37
C- Active Ingredient Quality & BioavailabilityF Dose, Safety & Label TransparencyF Value

Niacin is a supporting ingredient in a Vitamin C-focused formula rather than the main reason to choose it. The 70 mg amount may be useful, but the chemical form is not identified and a standard tablet offers no release control. Cost efficiency is weak for niacin specifically.

View ingredientView products
Loading alternative details
87 Performance

Pure Buffered Magnesium Ascorbate

NOW
Magnesium ascorbate provides fully buffered vitamin C with clear mineral disclosure and a focused formula. Use directions and inactive ingredients are missing, but the active form is easier to assess than the original unspecified form.
82 Performance

Meta-C 1000 mg Tablets

NutriBiotic Immunity
A named vitamin C complex with calcium and metabolites offers a potentially gentler and more clearly characterized core. Spirulina adds limited value, yet disclosure and serving efficiency improve on the original premium formula.
82 Performance

Liposomal Vitamin C 1000 mg

SunLipid
Buffered vitamin C with a phospholipid complex and MCT provides a purposeful delivery-focused alternative. The sodium contribution may matter on a strict sodium limit, and niacin is not included.
89 Budget

Pure Buffered Calcium Ascorbate

NOW
Buffered calcium ascorbate supplies a meaningful vitamin C amount with a digestive-comfort advantage and much stronger value. It omits the original niacin and minor supporting ingredients, but the core active is clearer.
87 Budget

100% Pure Vitamin C Powder

Swanson Premium Brand
Pure ascorbic acid powder provides flexible dosing and exceptional economy without decorative extras. The unbuffered form may be less comfortable for sensitive users, and it does not supply niacin.
88 Budget

Buffered Gold C

California Gold Nutrition
Buffered sodium ascorbate offers a substantial, simple vitamin C serving at much better value. Users limiting sodium should count the disclosed contribution, and the formula leaves out the original niacin.
88 Value

Sodium Ascorbate Capsules

NutriBiotic Immunity
Buffered sodium ascorbate provides clear vitamin C dosing with excellent long-supply value. Sodium-restricted users should include its contribution in their daily total, and the formula does not replace niacin.
86 Value

Ester-C Plus 1000 mg Vitamin C

Solgar
Buffered vitamin C and citrus bioflavonoids create a focused formula with good stomach-comfort potential and sound value. Complete excipient and use details are unavailable, and niacin is absent.
87 Value

C 500 mg

Mason Natural
A moderate vitamin C amount provides simple daily support with excellent value. Generic ascorbic acid and missing inactive-ingredient details limit refinement, but the formula avoids paying for lightly dosed extras.
Report alternatives

Sources

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

  1. Effect of Vitamin C Supplements on Respiratory Tract Infections: A Systematic Review and Meta-Analysis.
    Keya TA; Leela A; Fernandez K; Habib N; Rashid M · Current reviews in clinical and experimental pharmacology · 2022
    Meta-analysis10 studies pooledImmunity forVitamin C
  2. Vitamin C and postoperative outcomes following mandibular third molar extraction: a randomized split-mouth study.
    Demirel M; Aktas A; Kizil M; Yalcin N · Oral surgery, oral medicine, oral pathology and oral radiology · 2026
    Randomized trial56 participantsSkin Health forVitamin C
  3. Vitamin C for the management of COVID-19: a systematic review and meta-analysis of randomized controlled trials.
    Abid H; Mushtaq I; Munir ABI; Shakil J; Vinjamuri S; Tadasare N; Kiran F; Muhammad Wali Mirza A; Fatima Khidri F; Shahid A; Ayyan M; Ehsan M; Cheema HA; Alsubari AMA; Sahra S; Siddiqi NI · Annals of medicine and surgery (2012) · 2026
    Meta-analysis9 studies pooledImmunity forVitamin C
  4. Association between hemoglobin A1c, Vitamin C, and microbiome in diabetic foot ulcers and intact skin: A cross-sectional study.
    Tong KPS; Green SJ; Ortiz J; Wu SC · Health science reports · 2024
    Cross-sectional study42 participantsSkin Health forVitamin C
  5. Immunocompetence and oxidant defense during ascorbate depletion of healthy men.
    Jacob RA; Kelley DS; Pianalto FS; Swendseid ME; Henning SM; Zhang JZ; Ames BN; Fraga CG; Peters JH · The American journal of clinical nutrition · 1992
    Clinical trial8 participantsImmunity forVitamin C
  6. 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
  7. 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
  8. 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
  9. 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
  10. 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
  11. Intake of vitamin C, vitamin E, selenium, zinc and polyunsaturated fatty acids and upper respiratory tract infection-a prospective cohort study.
    Raposo SE; Fondell E; Ström P; Bälter O; Bonn SE; Nyrén O; Plymoth A; Bälter K · European journal of clinical nutrition · 2018
    Cohort study1,533 participantsImmunity forVitamin C
  12. Comparison of the Efficacy of Intralesional Ascorbic Acid Mesotherapy and Intralesional Tranexamic Acid in Treating Melasma in the Skin of Colour Population.
    Aslam H; Muhammad A; Ullah A; Aziz N; Lakhiar JA; Ahmad B; Shahzadi A; Ahmad A; Chandni; Virdi G · Cureus · 2025
    Randomized trial110 participantsSkin Health forVitamin C
  13. Efficacy and Safety of tranexamic acid versus vitamin c after microneedling in treatment of melasma: Clinical and Dermoscopic study.
    El Attar Y; Doghaim N; El Far N; El Hedody S; Hawwam SA · Journal of cosmetic dermatology · 2022
    Randomized trial20 participantsSkin Health forVitamin C
  14. Dietary intake and supplement use of vitamins C and E and upper respiratory tract infection.
    Fondell E; Bälter O; Rothman KJ; Bälter K · Journal of the American College of Nutrition · 2012
    Cohort study1,509 participantsImmunity forVitamin C
  15. Comparative Evaluation of Locally Injected Dexamethasone with and Without Vitamin C in Mandibular Fractures: A Randomized Controlled Trial.
    Chincholkar A; Rudagi BM; Setiya S; Sakhariya S · Journal of maxillofacial and oral surgery · 2025
    Randomized trial30 participantsSkin Health forVitamin C
  16. Vitamin C supplementation and salivary immune function following exercise-heat stress.
    Carrillo AE; Murphy RJ; Cheung SS · International journal of sports physiology and performance · 2009
    Randomized trial12 participantsImmunity forVitamin C
  17. Double-blind, half-face study comparing topical vitamin C and vehicle for rejuvenation of photodamage.
    Fitzpatrick RE; Rostan EF · Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.] · 2002
    Non-randomized trial10 participantsSkin Health forVitamin C
  18. 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
  19. Split-Face Comparative Analysis Of Micro-Needling With Tranexamic Acid Vs Vitamin C Serum In Melasma.
    Raza MH; Iftikhar N; Anwar A; Mashhood AA; Tariq S; Bin Hamid MA · Journal of Ayub Medical College, Abbottabad : JAMC · 2022
    Non-randomized trial30 participantsSkin Health forVitamin C
  20. The effect of macronutrient and micronutrient supplements on COVID-19: an umbrella review.
    SeyedAlinaghi S; Shahidi R; Mojdeganlou H; Akhtaran FK; Maroufi SF; Maroufi SP; Mirzapour P; Karimi A; Khodaei S; Pour MM; Mehraeen E; Dadras O · Journal of health, population, and nutrition · 2024
    Systematic review28 studies pooledImmunity forVitamin C
  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. 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
  27. 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
  28. 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
  29. 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
  30. 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
  31. 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
  32. 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
  33. The effect of niacinamide on reducing cutaneous pigmentation and suppression of melanosome transfer.
    Hakozaki T; Minwalla L; Zhuang J; Chhoa M; Matsubara A; Miyamoto K; Greatens A; Hillebrand GG; Bissett DL; Boissy RE · The British journal of dermatology · 2002
    Randomized trial138 participantsSkin Health forNiacin
  34. Niacinamide: A B vitamin that improves aging facial skin appearance.
    Bissett DL; Oblong JE; Berge CA · Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.] · 2005
    Randomized trial50 participantsSkin Health forNiacin
  35. The clinical anti-aging effects of topical kinetin and niacinamide in Asians: a randomized, double-blind, placebo-controlled, split-face comparative trial.
    Chiu PC; Chan CC; Lin HM; Chiu HC · Journal of cosmetic dermatology · 2008
    Randomized trial52 participantsSkin Health forNiacin
  36. A Phase 3 Randomized Trial of Nicotinamide for Skin-Cancer Chemoprevention.
    Chen AC; Martin AJ; Choy B; Fernández-Peñas P; Dalziell RA; McKenzie CA; Scolyer RA; Dhillon HM; Vardy JL; Kricker A; St George G; Chinniah N; Halliday GM; Damian DL · The New England journal of medicine · 2015
    Randomized trial386 participantsSkin Health forNiacin
  37. Nicotinamide for Skin Cancer Chemoprevention.
    Breglio KF; Knox KM; Hwang J; Weiss R; Maas K; Zhang S; Yao L; Madden C; Xu Y; Hartman RI; Wheless L · JAMA dermatology · 2025
    Cohort study33,822 participantsSkin Health forNiacin
  38. 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
  39. 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