Product Image

Extra Strength Hair Skin & Nails

Nature's Bounty Optimal Solutions
4.6
★ ★ ★ ★ ★
(115433 ratings)
Manganese 5 mg
Biotin 5000 mcg
Niacin 25 mg
PABA 10 mg
Iron 3 mg
Product Image
Score72
Best suited to skin health, with the clearest benefits coming from the disclosed active ingredients. Collagen, horsetail, and alpha lipoic acid remain too lightly dosed to add much depth, and the excipient list is missing.
How scoring works
Quantity:150 Softgel(s) • (50 servings)
Goals:
Skin Health
Nail Health
Hair Health

Score 72

Best suited to skin health, with the clearest benefits coming from the disclosed active ingredients. Collagen, horsetail, and alpha lipoic acid remain too lightly dosed to add much depth, and the excipient list is missing.
How scoring works

Also available as

1 option
250 servings 3 Softgel(s) • 250 Softgel(s) • 83 servings $24.99 ($0.30 per serving)
$11.40($0.22 per serving)
Vitacost
$ 18.03
iHerb
$ 18.03
iHerb
$ 18.03
Walmart
$ 11.40
Amazon
$ 11.40
Report prices

Analysis

Biotin, zinc, selenium, hyaluronic acid, and supporting vitamins provide relevant hair, skin, and nail coverage at a low serving cost. Collagen, horsetail, and alpha lipoic acid remain too lightly dosed to add much depth, and the excipient list is missing. The 5,000 mcg biotin amount may distort thyroid, hormone, and cardiac laboratory results.

Vitamin C directly supports collagen synthesis and antioxidant defense in skin. Vitamin C has established human and mechanistic evidence for collagen formation and antioxidant protection. The clearly disclosed 1,000 mg vitamin C amount provides more than enough collagen-synthesis cofactor for most users.

Biotin and several micronutrients provide nutritional hair support, but the collagen and horsetail amounts are too small to add meaningful structure. The formula is broad yet relies heavily on high-dose biotin rather than balanced hair-specific depth. Useful vitamin and mineral forms are disclosed alongside several token add-ons.

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

Pros

  • Biotin, zinc, selenium, hyaluronic acid, and supporting vitamins provide relevant hair, skin, and nail coverage at a low serving cost.
  • The 5,000 mcg biotin amount may distort thyroid, hormone, and cardiac laboratory results.
  • Vitamin C directly supports collagen synthesis and antioxidant defense in skin.
  • Vitamin C has established human and mechanistic evidence for collagen formation and antioxidant protection.
  • The clearly disclosed 1,000 mg vitamin C amount provides more than enough collagen-synthesis cofactor for most users.

Cons

  • Collagen, horsetail, and alpha lipoic acid remain too lightly dosed to add much depth, and the excipient list is missing.
  • Vitamin C covers collagen synthesis and antioxidant defense but not direct hydration or barrier-lipid support.
  • The range of actives fits a hair, skin, and nails concept but relies heavily on biotin for meaningful nail support.
  • Hydrolyzed collagen is an appropriate form, yet its amount is only a trace and horsetail is similarly underdosed.
  • Biotin and several micronutrients provide nutritional hair support, but the collagen and horsetail amounts are too small to add meaningful structure.

Warnings

  • The 5,000 mcg biotin amount may distort thyroid, hormone, and cardiac laboratory results.
  • The label is detailed, but the crowded formula includes several marginal additions, and high-dose biotin should be disclosed before blood testing because it can distort some results.
  • High-dose biotin can distort laboratory tests, and excessive total preformed vitamin A may contribute to hair shedding.
  • Because 5,000 mcg of biotin can interfere with some lab tests, tell the testing clinician before blood work.

Nutrient quality

61 Moderate impact

Natural vitamin E and several mineral gluconates are reasonable choices. The beauty core is meaningful, but collagen, horsetail, argan oil, and alpha-lipoic acid are too small to add much.

Ingredient transparency

77 High impact

Specific active amounts are supplied without a hidden blend. Duplicate thiamine naming, unspecified biotin form, and missing excipients 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 purpose-specific experiences.

Value for money

79 High impact

The low serving cost and meaningful beauty-nutrient core provide strong value. Token-dose collagen and other extras add little, but the core remains competitive.

Report analysis

Goals

Skin Health
Skin Health
Impact
Highest effect
A- Goal FitA- Strength of SupportC+ CoverageA Formula Quality
Hyaluronic Acid · 30 mgZinc · 7.5 mgVitamin C · 60 mgCollagen · 50 mgSelenium · 12.5 mcgVitamin E · 10 mg

Vitamin C directly supports collagen synthesis and antioxidant defense in skin. Vitamin C has established human and mechanistic evidence for collagen formation and antioxidant protection.

The clearly disclosed 1,000 mg vitamin C amount provides more than enough collagen-synthesis cofactor for most users. Vitamin C covers collagen synthesis and antioxidant defense but not direct hydration or barrier-lipid support.

Study evidence
Collagen Supportive 62 studies
Vitamin C Supportive 53 studies
Nail Health
Nail Health
Impact
High effect
A- Goal FitB- Strength of SupportB CoverageC+ Formula Quality
Collagen · 50 mgBiotin · 5000 mcgHorsetail · 3 mg

Biotin provides a strong keratin pathway, while zinc, iron, vitamin C, vitamin E, B vitamins, and small amounts of collagen and horsetail broaden the formula. The range of actives fits a hair, skin, and nails concept but relies heavily on biotin for meaningful nail support.

Hydrolyzed collagen is an appropriate form, yet its amount is only a trace and horsetail is similarly underdosed. The label is detailed, but the crowded formula includes several marginal additions, and high-dose biotin should be disclosed before blood testing because it can distort some results.

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

No linked studies yet.

Iron Disputed 4 studies
Selenium Adverse 1 study
Vitamin C Supportive 1 study
Vitamin E Supportive 6 studies
Zinc No effect 1 study
Hair Health
Hair Health
Impact
Moderate effect
C+ Goal FitC+ Strength of SupportC+ CoverageD Formula Quality
Biotin · 5000 mcgZinc · 7.5 mgIron · 3 mgVitamin C · 60 mgCollagen · 50 mg

Biotin and several micronutrients provide nutritional hair support, but the collagen and horsetail amounts are too small to add meaningful structure. The formula is broad yet relies heavily on high-dose biotin rather than balanced hair-specific depth.

Useful vitamin and mineral forms are disclosed alongside several token add-ons. High-dose biotin can distort laboratory tests, and excessive total preformed vitamin A may contribute to hair shedding.

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

No linked studies yet.

Iron Disputed 25 studies
Selenium Disputed 7 studies
Vitamin A Disputed 13 studies
Zinc Supportive 22 studies

Ingredients

IngredientAmount per serving
Calories
15 Calorie(s)
Total Fat
1 Gram(s)
Vitamin A (Retinyl Palmitate)
 1500 mcg
Vitamin C (Ascorbic Acid)
 60 mg
Vitamin E (D-Alpha-Tocopheryl Acetate)
 10 mg
Thiamine (Thiamine Mononitrate, Vitamin B1)
 3 mg
Riboflavin (Vitamin B2)
 5 mg
Niacin (Niacinamide)
 25 mg
Vitamin B6 (Pyridoxine Hydrochloride)
 5 mg
Folate
333 mcg DFE
Vitamin B12 (Cyanocobalamin)
 8 mcg
Biotin
5000 mcg
Pantothenic Acid (Calcium D-Pantothenate)
 4 mg
Iron (Ferrous Gluconate)
 3 mg
Zinc (Zinc Gluconate)
 7.5 mg
Selenium (Selenium Yeast)
 12.5 mcg
Manganese (Manganese Gluconate)
 5 mg
Argan Oil (Argania spinosa)
 25 mg
PABA
10 mg
Alpha Lipoic Acid
10 mg
Horsetail
3 mg
Collagen, Hydrolyzed
50 mg
Hyaluronic Acid (Sodium Hyaluronate)
 30 mg
Gluten Free Adults 18–50 Dairy Free Sugar Free
Report overview
Manganese (Manganese Gluconate) · 5 mg OverallScore92
B+ Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyA+ Value

The broad beauty formula pairs a targeted manganese amount with a soluble organic form. The elemental amount reaches the preferred range without exceeding established upper limits. The very low serving cost gives it excellent manganese-specific value.

View ingredientView products
Biotin · 5000 mcg OverallScore89
B+ Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyB+ Value

The 5,000 mcg dose reaches the high-potency range, although the label does not verify the active d-biotin isomer. The softgel format is practical, and the broad formula makes a biotin-only cost comparison incomplete. Because 5,000 mcg of biotin can interfere with some lab tests, tell the testing clinician before blood work.

View ingredientView products
Niacin (Niacinamide) · 25 mg OverallScore76
A Active Ingredient Quality & BioavailabilityC+ Dose, Safety & Label TransparencyC Value

Niacinamide matches the skin-focused purpose and comes in a rapid-release softgel. The amount is useful as part of a beauty blend but is modest for niacinamide as a primary skin active. The broader formula provides fair value, though niacin is not the main reason to buy it.

View ingredientView products
Loading alternative details
70 Performance

Hair Skin & Nails

Nature's Truth
Vitamin D3, natural vitamin E, vitamin C, zinc, selenium, high biotin, silica, collagen, hyaluronic acid, horsetail, and oils closely match the beauty goal. Structural ingredients are still token amounts, and high biotin plus preformed vitamin A preserve the main safety cautions.
67 Performance

Extra Strength Hair Skin & Nails Argan Oil Infused

Nature's Bounty Optimal Solutions
High biotin, argan oil, hyaluronic acid, collagen, horsetail, zinc, selenium, iron, and choline provide a close hair-and-nail match with broad supporting nutrients. High biotin and preformed vitamin A still require laboratory and pregnancy caution, while collagen remains lightly represented.
69 Performance

Extra Strength Hair Skin & Nails

21st Century
High biotin, collagen, horsetail, zinc, manganese, choline, inositol, PABA, and broad vitamins form a coherent beauty-support formula. Collagen is not clearly substantial and high biotin still affects laboratory testing, but the nutrient breadth is useful.
81 Budget

B-Complex with Folic Acid plus Vitamin C

Nature's Bounty
A lower serving cost supplies biotin, folate, vitamin B12, pantothenic acid, vitamin B6, niacin, and vitamin C in a straightforward formula. It lacks zinc, collagen, hyaluronic acid, horsetail, and argan oil, but also avoids preformed vitamin A.
78 Budget

Women's One Daily

INNATE Response Formulas
A lower serving cost provides broad vitamins, minerals, folate, biotin, zinc, selenium, iron, and active chromium in a more balanced daily formula. It is less hair-focused and contains a proprietary food-and-herb blend, but avoids token collagen and hyaluronic acid.
79 Budget

Women's Complete Multivitamin

Bayer One A Day Women's
A lower serving cost offers broad vitamins, iron, iodine, magnesium, zinc, selenium, and biotin with strong general nutrient coverage. It lacks collagen, hyaluronic acid, horsetail, argan oil, and PABA, but has a simpler core purpose.
68 Value

Hair Skin & Nails

Sundown
High biotin, zinc, manganese, collagen, horsetail, PABA, choline, inositol, and broad vitamins provide close ingredient overlap at a modest serving cost. High biotin and preformed vitamin A remain concerns, and structural ingredients are not shown as substantial.
74 Value

Raw One for Women

Garden of Life Vitamin Code
Broad vitamins, active folate, biotin, zinc, selenium, iron, manganese, and amla provide balanced hair-related nutrition at reasonable value. Fruit, vegetable, probiotic, and enzyme blends are not fully detailed, but the formula avoids token collagen and hyaluronic acid.
69 Value

Hema-Plex Chewables Delicious Mixed Berry Flavor

NaturesPlus
Iron, zinc, selenium, folate, vitamin B12, vitamin C, and cysteine provide a more targeted nutrient base for hair-related deficiencies at a moderate serving cost. It lacks biotin, collagen, silica, and hyaluronic acid, so the fit depends on the user's actual nutrient needs.
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. The Association Between Alopecia Areata and Iron Deficiency Anemia: A Large-Scale Population-Based Case-Control Study.
    Davidovici B; Drutin Y; Ben-Tov A; Mimouni D; Wohl Y · Journal of personalized medicine · 2026
    Case-control study100,203 participantsHair Health forIron
  18. Iron Deficiency and Nonscarring Alopecia in Women: Systematic Review and Meta-Analysis.
    Treister-Goltzman Y; Yarza S; Peleg R · Skin appendage disorders · 2022
    Meta-analysis10,029 participants36 studies pooledHair Health forIron
  19. Comparative Analysis of Postoperative Hair Loss and Micronutrient Deficiencies After One-Anastomosis Gastric Bypass Versus Sleeve Gastrectomy.
    Chinisaz F; Maleki T; Najjari K; Miratashi Yazdi SA · Obesity surgery · 2026
    Cohort study261 participantsHair Health forIron
  20. Assessment of Serum Ferritin Levels in Female Patients With Telogen Effluvium.
    Thamotharan N; Harikumar MV; Sundaram M; Swaminathan A; Rangarajan S · Cureus · 2026
    Cross-sectional study100 participantsHair Health forIron
  21. Diagnosis and treatment of female alopecia: Focusing on the iron deficiency-related alopecia.
    Lin CS; Chan LY; Wang JH; Chang CH · Tzu chi medical journal · 2023
    Cohort study155 participantsHair Health forIron
  22. Beyond Efficacy: 0.6% Selenium Disulfide Shampoo Matches 2% Ketoconazole for Seborrheic Dermatitis with Superior Cosmesis.
    Farris PK; Barbosa V; Houshman EB; Kovylkina N · Journal of drugs in dermatology : JDD · 2026
    Randomized trial87 participantsHair Health forSelenium
  23. Selenium Disulfide-based shampoo applied for 4 weeks significantly improves dandruff and seborrheic dermatitis.
    Turcu G; Artenie C; Nowicka D; Arenbergerová M; Lazaridou E; Khobzei K; Ataseven A; Part M; Leclerc-Mercier S · European journal of dermatology : EJD · 2023
    Observational study1,407 participantsHair Health forSelenium
  24. A Comparative Randomized Clinical Study Assessing the Efficacy of a 1% Selenium Disulfide-Based Shampoo versus 2% Ketoconazole Shampoo in Subjects with Moderate to Severe Scalp Seborrheic Dermatitis.
    Barbosa V; Melo DF; Vañó-Galván S; Lutchmanen-Kolanthan V; Sant'Anna B; Leclerc-Mercier S; Reygagne P · Skin appendage disorders · 2025
    Randomized trial64 participantsHair Health forSelenium
  25. Changes of serum trace elements level in patients with alopecia areata: A meta-analysis.
    Jin W; Zheng H; Shan B; Wu Y · The Journal of dermatology · 2018
    Meta-analysis764 participantsHair Health forSelenium
  26. Scientific opinion on the tolerable upper intake level for selenium.
    EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA); Turck D; Bohn T; Castenmiller J; de Henauw S; Hirsch-Ernst KI; Knutsen HK; Maciuk A; Mangelsdorf I; McArdle HJ; Peláez C; Pentieva K; Siani A; Thies F; Tsabouri S; Vinceti M; Aggett P; Crous Bou M; Cubadda F; Ciccolallo L; de Sesmaisons Lecarré A; Fabiani L; Titz A; Naska A · EFSA journal. European Food Safety Authority · 2023
    Systematic reviewHair Health forSelenium
  27. Topical tretinoin for hair growth promotion.
    Bazzano GS; Terezakis N; Galen W · Journal of the American Academy of Dermatology · 1986
    Non-randomized trial56 participantsHair Health forVitamin A
  28. A review of isotretinoin in the treatment of frontal fibrosing alopecia.
    Shahpar A; Nezhad NZ; Sahaf AS; Ahramiyanpour N · Journal of cosmetic dermatology · 2024
    Systematic review232 participants15 studies pooledHair Health forVitamin A
  29. Efficacy of Isotretinoin and Acitretin in Treatment of Frontal Fibrosing Alopecia: Retrospective Analysis of 54 Cases.
    Rakowska A; Gradzińska A; Olszewska M; Rudnicka L · Journal of drugs in dermatology : JDD · 2018
    Cohort study54 participantsHair Health forVitamin A
  30. Systemic Treatments for Lichen Planopilaris and Frontal Fibrosing Alopecia: A Retrospective Study of 315 Patients.
    Willaert M; Van Dongen T; Dikrama P; Nijsten T; Hijnen D; Waalboer-Spuij R · Acta dermato-venereologica · 2025
    Cohort study315 participantsHair Health forVitamin A
  31. Tretinoin enhances minoxidil response in androgenetic alopecia patients by upregulating follicular sulfotransferase enzymes.
    Sharma A; Goren A; Dhurat R; Agrawal S; Sinclair R; Trüeb RM; Vañó-Galván S; Chen G; Tan Y; Kovacevic M; Situm M; McCoy J · Dermatologic therapy · 2020
    Single-arm trialHair Health forVitamin A
  32. 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
  33. 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
  34. 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
  35. 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
  36. 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
  37. 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
  38. 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 forIron Nail Health forVitamin E Nail Health forZinc
  39. 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
  40. 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
  41. 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
  42. A pilot iron substitution programme in female blood donors with iron deficiency without anaemia.
    Pittori C; Buser A; Gasser UE; Sigle J; Job S; Rüesch M; Tichelli A; Infanti L · Vox sanguinis · 2011
    Non-randomized trial224 participantsNail Health forIron
  43. Evaluation of nail abnormalities.
    Tully AS; Trayes KP; Studdiford JS · American family physician · 2013
    Narrative reviewNail Health forIron
  44. Efficacy and tolerability of a biomineral formulation for treatment of onychoschizia: a randomized trial
    Adele Sparavigna, Beatrice Tenconi, Laura La Penna · Clinical, Cosmetic and Investigational Dermatology · 2019
    Randomized trial48 participantsNail Health forIron
  45. Acute selenium toxicity associated with a dietary supplement.
    MacFarquhar JK; Broussard DL; Melstrom P; Hutchinson R; Wolkin A; Martin C; Burk RF; Dunn JR; Green AL; Hammond R; Schaffner W; Jones TF · Archives of internal medicine · 2010
    Observational study201 participantsNail Health forSelenium
  46. 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
  47. Dermatologic signs in patients with eating disorders.
    Strumia R · American journal of clinical dermatology · 2005
    Narrative reviewNail Health forVitamin E
  48. Yellow nail syndrome: clinical experience in a series of 21 patients.
    Piraccini BM; Urciuoli B; Starace M; Tosti A; Balestri R · Journal der Deutschen Dermatologischen Gesellschaft = Journal of the German Society of Dermatology : JDDG · 2014
    Case series20 participantsNail Health forVitamin E
  49. Why don't we use vitamin E in dermatology?
    Pehr K; Forsey RR · CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne · 1993
    Systematic reviewNail Health forVitamin E
  50. Diagnosis and management of yellow nail syndrome: An international multi-institutional retrospective cohort study of 111 cases by an expert panel.
    Curtis KL; Piraccini BM; Starace M; Rapparini L; Richert B; Rubin AI; Jellinek NJ; Tosti A; Di Chiacchio NG; Di Chiacchio N; Iorizzo M; Grover C; Hinshaw MA; Vlahovic TC; Bellet JS; Rigopoulos D; Lipner SR · Journal of the American Academy of Dermatology · 2025
    Cohort study111 participantsNail Health forVitamin E
  51. 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
  52. 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
  53. 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
  54. 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
  55. 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
  56. 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
  57. 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
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