Product Image

Extra Strength Hair Skin & Nails

21st Century
4.6
★ ★ ★ ★ ★
(39016 ratings)
Phosphorus 180 mg
Biotin 5000 mcg
Manganese 2 mg
Niacin 25 mg
PABA 10 mg
Calcium 372 mg
Choline 10 mg
Product Image
Score69
Best suited to nail health, with the clearest benefits coming from the disclosed active ingredients. Calcium carbonate, magnesium oxide, synthetic vitamin E, trace collagen, and minimal horsetail limit quality and structural depth.
How scoring works
Quantity:90 Tablet(s) • (30 servings)
Goals:
Nail Health
Hair Health
Skin Health

Score 69

Best suited to nail health, with the clearest benefits coming from the disclosed active ingredients. Calcium carbonate, magnesium oxide, synthetic vitamin E, trace collagen, and minimal horsetail limit quality and structural depth.
How scoring works

Also available as

1 option
25mcg Biotin • 50 Tablet(s) servings 25mcg Biotin • 50 Tablet(s) • 50 servings $7.49 ($0.14 per serving)
$9.99($0.33 per serving)
iHerb
$ 9.99
Amazon
$ 9.99
iHerb
$ 9.99
Report prices

Analysis

High-potency d-biotin, vitamin C, vitamin D3, zinc, and several B vitamins support a clear hair, skin, and nail purpose. Calcium carbonate, magnesium oxide, synthetic vitamin E, trace collagen, and minimal horsetail limit quality and structural depth. The low serving cost supports good value, although several ingredients serve more as label decoration than effective beauty support.

High-dose d-biotin directly targets nail firmness, while zinc, vitamin C, B vitamins, and a small collagen amount add support. Collagen and horsetail are present only in trace amounts, so most of the practical contribution comes from biotin. Clear d-biotin labeling and transparent micronutrient amounts are strengths, although several supporting forms are basic.

Hydrolyzed gelatin, vitamin C, zinc, biotin, and horsetail directly reference structural and nutrient pathways for hair and skin. Evidence supports vitamin C and zinc, while the tiny collagen and horsetail amounts are unlikely to improve skin structure. The 50 mg collagen and 3 mg horsetail amounts are token additions despite a high biotin dose.

Who is it for
  • People seeking nail health support
  • People seeking hair health support
  • People seeking skin health support
Best for
  • Nail Health
  • Hair Health
  • Skin Health

Pros

  • High-potency d-biotin, vitamin C, vitamin D3, zinc, and several B vitamins support a clear hair, skin, and nail purpose.
  • The low serving cost supports good value, although several ingredients serve more as label decoration than effective beauty support.
  • The high biotin amount can distort thyroid, hormone, and cardiac troponin blood tests, so use should be disclosed before laboratory testing.
  • High-dose d-biotin directly targets nail firmness, while zinc, vitamin C, B vitamins, and a small collagen amount add support.
  • Clear d-biotin labeling and transparent micronutrient amounts are strengths, although several supporting forms are basic.

Cons

  • Calcium carbonate, magnesium oxide, synthetic vitamin E, trace collagen, and minimal horsetail limit quality and structural depth.
  • Collagen and horsetail are present only in trace amounts, so most of the practical contribution comes from biotin.
  • The collagen amount is only a trace and is far below a meaningful peptide serving, while horsetail is similarly token.
  • The 50 mg collagen and 3 mg horsetail amounts are token additions despite a high biotin dose.
  • D-biotin is clearly identified, but hydrolyzed gelatin lacks collagen type and the mineral forms are mostly basic.

Warnings

  • The high biotin amount can distort thyroid, hormone, and cardiac troponin blood tests, so use should be disclosed before laboratory testing.
  • High-dose biotin can interfere with some laboratory tests, so users should tell the testing clinician before blood work.
  • High-dose biotin can interfere with some laboratory tests, so the testing clinician should be told before blood work.
  • The 5,000 mcg biotin serving can interfere with some laboratory tests, so users should tell the testing clinician before blood work.

Nutrient quality

58 Moderate impact

D-biotin and vitamin D3 are useful core forms. Basic mineral forms and numerous very small extras limit depth.

Ingredient transparency

75 High impact

Most active amounts are listed and no proprietary blend is shown. Repeated calcium entries and missing excipient details reduce clarity.

Customer satisfaction

71 High impact

The supplied average rating is strong and backed by an exceptionally large review base. No review text is available to assess recurring complaints or goal-specific experiences.

Value for money

71 High impact

The low-cost biotin and vitamin core provides good basic value. Token-dose structural ingredients and basic mineral forms limit quality depth.

Report analysis

Goals

Nail Health
Nail Health
Impact
High effect
B+ Goal FitB Strength of SupportB- CoverageB- Formula Quality
Collagen · 50 mgBiotin · 5000 mcgHorsetail · 3 mg

High-dose d-biotin directly targets nail firmness, while zinc, vitamin C, B vitamins, and a small collagen amount add support. Collagen and horsetail are present only in trace amounts, so most of the practical contribution comes from biotin.

Clear d-biotin labeling and transparent micronutrient amounts are strengths, although several supporting forms are basic. High-dose biotin can interfere with some laboratory tests, so users should tell the testing clinician before blood work.

Study evidence
Biotin Supportive 8 studies
Collagen Supportive 4 studies
Horsetail Not classified

No linked studies yet.

Vitamin C Supportive 1 study
Zinc No effect 1 study
Hair Health
Hair Health
Impact
Moderate effect
C+ Goal FitC+ Strength of SupportD+ CoverageC- Formula Quality
Biotin · 5000 mcgVitamin D · 25 mcgZinc · 7.5 mgVitamin C · 60 mgCollagen · 50 mg

D-biotin is supplied at a strong hair-oriented amount and is paired with vitamin D3, vitamin C, and zinc. These nutrients can support hair quality when a shortfall is present.

The collagen amount is only a trace and is far below a meaningful peptide serving, while horsetail is similarly token. High-dose biotin can interfere with some laboratory tests, so the testing clinician should be told before blood work.

Study evidence
Biotin Supportive 4 studies
Collagen Supportive 3 studies
Horsetail Not classified

No linked studies yet.

Vitamin C Mixed 5 studies
Zinc Supportive 22 studies
Skin Health
Skin Health
Impact
Moderate effect
C Goal FitD Strength of SupportC- CoverageC+ Formula Quality
Zinc · 7.5 mgVitamin C · 60 mgCollagen · 50 mgVitamin E · 6.75 mg

Hydrolyzed gelatin, vitamin C, zinc, biotin, and horsetail directly reference structural and nutrient pathways for hair and skin. Evidence supports vitamin C and zinc, while the tiny collagen and horsetail amounts are unlikely to improve skin structure.

The 50 mg collagen and 3 mg horsetail amounts are token additions despite a high biotin dose. D-biotin is clearly identified, but hydrolyzed gelatin lacks collagen type and the mineral forms are mostly basic. The 5,000 mcg biotin serving can interfere with some laboratory tests, so users should tell the testing clinician before blood work.

Study evidence
Biotin Supportive 10 studies
Collagen Supportive 62 studies
Vitamin C Supportive 53 studies
Zinc Supportive 66 studies

Ingredients

IngredientAmount per serving
Vitamin A (Retinyl Palmitate)
 1500 mcg
Vitamin C (Ascorbic Acid)
 60 mg
Vitamin D3 (Cholecalciferol)
 25 mcg
Vitamin E (DL-Alpha-Tocopheryl Acetate)
 6.75 mg
Thiamine (Thiamine Hydrochloride)
 5 mg
Riboflavin (Vitamin B2)
 2 mg
Niacin (Niacinamide)
 25 mg
Vitamin B6 (Pyridoxine Hydrochloride)
 5 mg
Folate
334 mcg DFE
Vitamin B12 (Cyanocobalamin)
 8 mcg
Biotin (D-Biotin)
 5000 mcg
Pantothenic Acid (D-Calcium Pantothenate)
 15 mg
Choline (Choline Bitartrate)
 10 mg
Calcium (Calcium Carbonate, Dicalcium Phosphate)
 372 mg
Phosphorus (Dicalcium Phosphate)
 180 mg
Magnesium (Magnesium Oxide)
 50 mg
Zinc (Zinc Gluconate)
 7.5 mg
Manganese (Manganese Gluconate)
 2 mg
PABA
10 mg
Inositol
30 mg
Citrus Bioflavonoid / Rutin Complex
38 mg
Horsetail powder
3 mg
Collagen (hydrolyzed Gelatin)
 50 mg
Gluten Free Adults 18–50
Report overview
Phosphorus (Dicalcium Phosphate) · 180 mg OverallScore90
B Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyA+ Value

Dicalcium phosphate provides a reliable and clearly disclosed phosphorus source. The elemental amount fits targeted supplementation, although three tablets are only moderately convenient. A low serving cost gives the formula strong phosphorus price efficiency.

View ingredientView products
Biotin (D-Biotin) · 5000 mcg OverallScore87
A Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyD+ Value

The 5000 mcg biotin dose reaches the strongest target range for hair and nail support. The label explicitly verifies biologically active d-biotin. High-dose biotin can interfere with some laboratory tests, so users should tell the testing clinician before blood work.

View ingredientView products
Manganese (Manganese Gluconate) · 2 mg OverallScore82
B+ Active Ingredient Quality & BioavailabilityA- Dose, Safety & Label TransparencyB+ Value

The gluconate form provides good, though not top-tier, mineral quality. The clearly disclosed 2 mg amount supports nutritional maintenance but falls short of the target range for bone-matrix support. The modest serving cost provides good value for a broad beauty formula.

View ingredientView products
Loading alternative details
70 Performance

Body Hair Skin & Nails

Mason Natural
<p>Its label clearly provides 900mcg RAE of Vitamin A as Beta-Carotene, making it a more clearly defined biotin and choline and calcium and manganese and phosphorus and paba option. Compared with the original, its ingredient and goal alignment is stronger, although it does not retain the original product’s niacin coverage.</p>
72 Performance

Extra Strength Hair Skin & Nails

Nature's Bounty Optimal Solutions
<p>Its label clearly provides 3 mg of Horsetail, making it a more clearly defined niacin and biotin and manganese and paba option. Compared with the original, its ingredient and goal alignment is stronger, although it does not retain the original product’s choline and calcium and phosphorus coverage.</p>
70 Performance

Hair Skin & Nails

Nature's Truth
<p>Its label clearly provides 1 g of Total Fat, making it a more clearly defined niacin and biotin and paba option. Compared with the original, its ingredient and goal alignment is stronger, although it does not retain the original product’s choline and calcium and manganese and phosphorus coverage.</p>
65 Budget

High Potency B-Complex Chewable Natural Orange Flavor

Solaray
<p>Its label clearly provides 250 mg of Vitamin C as Ascorbic Acid, preserving relevant niacin and biotin and choline and paba coverage. Compared with the original, it lowers the serving cost, although it does not retain the original product’s calcium and manganese and phosphorus coverage.</p>
82 Budget

B-Complex with Rice Bran

NaturesPlus Source of Life Garden
<p>Its label clearly provides 10 mg of Thiamine as Thiamine Hydrochloride, preserving relevant niacin and choline and paba coverage. Compared with the original, it lowers the serving cost, although it does not retain the original product’s biotin and calcium and manganese and phosphorus coverage.</p>
71 Budget

B Complex

NATURELO Premium Supplements
<p>Its label clearly provides 2 mg of Co-Enzyme Q10 as Ubidecarenone, preserving relevant biotin and choline and paba coverage. Compared with the original, it lowers the serving cost, although it does not retain the original product’s niacin and calcium and manganese and phosphorus coverage.</p>
68 Value

Hair Skin & Nails

Sundown
<p>Its label clearly provides 1500 mcg of Vitamin A as Vitamin A Palmitate, keeping the formula relevant to niacin and biotin and choline and calcium and manganese and phosphorus and paba. Compared with the original, the lower serving cost and ingredient detail create a useful quality-to-cost balance, although the input does not provide independent testing or absorption evidence.</p>
70 Value

Hair Skin & Nails

Nature's Bounty Optimal Solutions
<p>Its label clearly provides 2 mg of Riboflavin as Vitamin B2, keeping the formula relevant to niacin and biotin and choline and manganese and phosphorus and paba. Compared with the original, the somewhat higher serving cost and ingredient detail create a useful quality-to-cost balance, although it does not retain the original product’s calcium coverage.</p>
57 Value

Hair Skin & Nails

21st Century
<p>Its label clearly provides 750mcg RAE of Vitamin A as Vitamin A Palmitate, keeping the formula relevant to choline and phosphorus and paba. Compared with the original, the lower serving cost and ingredient detail create a useful quality-to-cost balance, although it does not retain the original product’s niacin and biotin and calcium and manganese coverage.</p>
Report alternatives

Sources

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

  1. The Role of Sesbania grandiflora-Derived Biotin and Bambusa arundinacea-Derived Silica Extracts in Promoting Hair, Skin, and Nail Health: A Randomized, Double-Blind, Placebo-Controlled Clinical Study.
    Patel MN; Maheshvari J; Patel N · Cureus · 2025
    Randomized trial105 participantsSkin Health Hair Health Nail Health forBiotin
  2. The Infatuation With Biotin Supplementation: Is There Truth Behind Its Rising Popularity? A Comparative Analysis of Clinical Efficacy versus Social Popularity.
    Soleymani T; Lo Sicco K; Shapiro J · Journal of drugs in dermatology : JDD · 2018
    Narrative reviewHair Health forBiotin
  3. Vitamins A, B, C, and D: A Short Review for the Dermatologist.
    Coerdt KM; Goggins CA; Khachemoune A · Alternative therapies in health and medicine · 2021
    Narrative reviewHair Health forBiotin
  4. Low serum biotinidase activity in children with valproic acid monotherapy.
    Schulpis KH; Karikas GA; Tjamouranis J; Regoutas S; Tsakiris S · Epilepsia · 2001
    Clinical trial125 participantsSkin Health Hair Health forBiotin
  5. Evaluation of biophysical skin parameters and hair changes in patients with acne vulgaris treated with isotretinoin, and the effect of biotin use on these parameters.
    Aksac SE; Bilgili SG; Yavuz GO; Yavuz IH; Aksac M; Karadag AS · International journal of dermatology · 2021
    Non-randomized trial60 participantsSkin Health forBiotin
  6. Anti-pollution cosmetic-based one-step formation of w/o/w multiple emulsion containing D-biotin for skin protection: fabrication and in vitro and in vivo evaluation.
    Ali A; Iqbal S; Ilyas A; Khan H; Asad MHHB; Fatima N; Akhtar N · Drug delivery and translational research · 2020
    Non-randomized trial15 participantsSkin Health forBiotin
  7. Interventions for infantile seborrhoeic dermatitis (including cradle cap).
    Victoire A; Magin P; Coughlan J; van Driel ML · The Cochrane database of systematic reviews · 2019
    Systematic review35 participants2 studies pooledSkin Health forBiotin
  8. Final report on the safety assessment of biotin.
    Fiume MZ; Cosmetic Ingredient Review Expert Panel · International journal of toxicology · 2002
    Narrative reviewSkin Health forBiotin
  9. Biotin for the treatment of nail disease: what is the evidence?
    Lipner SR; Scher RK · The Journal of dermatological treatment · 2018
    Narrative reviewNail Health forBiotin
  10. Treatment of brittle fingernails and onychoschizia with biotin: scanning electron microscopy.
    Colombo VE; Gerber F; Bronhofer M; Floersheim GL · Journal of the American Academy of Dermatology · 1991
    Other32 participantsNail Health forBiotin
  11. Brittle nails: response to daily biotin supplementation.
    Hochman LG; Scher RK; Meyerson MS · Cutis · 1993
    Case series35 participantsNail Health forBiotin
  12. Nail Supplements: When, How, and Why?
    Zaraa I; Richert B · Skin appendage disorders · 2026
    Narrative reviewNail Health forBiotin Nail Health forCollagen
  13. Brittle nails.
    Iorizzo M; Pazzaglia M; M Piraccini B; Tullo S; Tosti A · Journal of cosmetic dermatology · 2009
    Narrative reviewNail Health forBiotin
  14. Low-Molecular-Weight Collagen Peptide Supplementation Improves Cellulite Severity, Skin Elasticity, and Hair Shaft Diameter: A Clinical Study with Pharmacokinetic Evaluation.
    Hwang S; Won J; Kim S; Kang W; Park M · Journal of medicinal food · 2026
    Randomized trial114 participantsHair Health forCollagen
  15. Calcium and Vitamin D Supplementation with and Without Collagen on Bone Density and Skin Elasticity in Menopausal Women-A Randomized Controlled Study.
    Duangjai A; Srivilai J; Nangola S; Amornlerdpison D · Clinics and practice · 2025
    Randomized trialHair Health forCollagen
  16. Dietary Collagen Supplementation as a Strategy for Skin Health: A Narrative Review of Clinical Effects on Skin, Hair, Nails, and Wound Healing.
    Biełach-Bazyluk A; Jurga M; Flisiak I; Zbroch E · Nutrients · 2026
    Narrative reviewHair Health forCollagen
  17. 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
  18. 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
  19. 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
  20. 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
  21. 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
  22. 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
  23. 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
  24. 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
  25. 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
  26. 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
  27. Treatment of brittle nail with a hydroxypropyl chitosan-based lacquer, alone or in combination with oral biotin: A randomized, assessor-blinded trial.
    Chiavetta A; Mazzurco S; Secolo MP; Tomarchio G; Milani M · Dermatologic therapy · 2020
    Randomized trial50 participantsNail Health forBiotin
  28. Vitamins and minerals: their role in nail health and disease.
    Scheinfeld N; Dahdah MJ; Scher R · Journal of drugs in dermatology : JDD · 2007
    Narrative reviewNail Health forBiotin Nail Health forZinc
  29. Oral supplementation with specific bioactive collagen peptides improves nail growth and reduces symptoms of brittle nails.
    Hexsel D; Zague V; Schunck M; Siega C; Camozzato FO; Oesser S · Journal of cosmetic dermatology · 2018
    Single-arm trial25 participantsNail Health forCollagen
  30. Influence of collagen peptide supplementation on visible signs of skin and nail health and -aging in an East Asian population: A double blind, randomized, placebo-controlled trial.
    Vleminckx S; Virgilio N; Asserin J; Prawitt J; Silva CIF · Journal of cosmetic dermatology · 2024
    Randomized trial85 participantsNail Health forCollagen
  31. Expanding the COL7A1 mutation database: novel and recurrent mutations and unusual genotype-phenotype constellations in 41 patients with dystrophic epidermolysis bullosa.
    Kern JS; Kohlhase J; Bruckner-Tuderman L; Has C · The Journal of investigative dermatology · 2006
    Observational study41 participantsNail Health forCollagen
  32. Vitamin C Deficiency in Inflammatory Bowel Disease: The Forgotten Micronutrient.
    Dunleavy KA; Ungaro RC; Manning L; Gold S; Novak J; Colombel JF · Crohn's & colitis 360 · 2023
    Other20 participantsNail Health forVitamin C
  33. Generalized seborrhoeic dermatitis. Clinical and therapeutic data of 25 patients.
    Messaritakis J; Kattamis C; Karabula C; Matsaniotis N · Archives of disease in childhood · 1976
    Non-randomized trial25 participantsSkin Health forBiotin
  34. Holocarboxylase synthetase deficiency: novel clinical and molecular findings.
    Tammachote R; Janklat S; Tongkobpetch S; Suphapeetiporn K; Shotelersuk V · Clinical genetics · 2010
    Case series4 participantsSkin Health forBiotin
  35. Exploring the Impact of Hydrolyzed Collagen Oral Supplementation on Skin Rejuvenation: A Systematic Review and Meta-Analysis.
    Dewi DAR; Arimuko A; Norawati L; Yenny SW; Setiasih NL; Perdiyana A; Arkania N; Nadhira F; Wiliantari N · Cureus · 2024
    Meta-analysis967 participants14 studies pooledSkin Health forCollagen
  36. Effects of collagen-based supplements on skin's hydration and elasticity: A systematic review and meta-analysis.
    Danessa G; Notario D; Regina R · Indian journal of dermatology, venereology and leprology · 2025
    Meta-analysis646 participants10 studies pooledSkin Health forCollagen
  37. Oral intake of collagen peptide NS improves hydration, elasticity, desquamation, and wrinkling in human skin: a randomized, double-blinded, placebo-controlled study.
    Lee M; Kim E; Ahn H; Son S; Lee H · Food & function · 2023
    Randomized trial100 participantsSkin Health forCollagen
  38. Oral Intake of Low-Molecular-Weight Collagen Peptide Improves Hydration, Elasticity, and Wrinkling in Human Skin: A Randomized, Double-Blind, Placebo-Controlled Study.
    Kim DU; Chung HC; Choi J; Sakai Y; Lee BY · Nutrients · 2018
    Randomized trial64 participantsSkin Health forCollagen
  39. Effects of hydrolyzed collagen supplementation on skin aging: a systematic review and meta-analysis.
    de Miranda RB; Weimer P; Rossi RC · International journal of dermatology · 2021
    Meta-analysis1,125 participants19 studies pooledSkin Health forCollagen
  40. 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
  41. 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
  42. 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
  43. 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
  44. 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
  45. 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
  46. 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
  47. 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
  48. 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
  49. 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