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Hair Multivitamin

California Gold Nutrition
4.6
★ ★ ★ ★ ★
(1131 ratings)
Biotin 5000 mcg
Methionine
Copper 2.7 mg
Riboflavin 6.5 mg
Collagen 100 mg
Product Image
Score64
A high-biotin hair formula centered on evening primrose oil. The collagen, amino acids, and hyaluronic acid are far too small to be major reasons to buy it.
How scoring works
Quantity:30 Capsule(s) • (15 servings)
Goals:
Nail Health
Hair Health

Score 64

A high-biotin hair formula centered on evening primrose oil. The collagen, amino acids, and hyaluronic acid are far too small to be major reasons to buy it.
How scoring works
$20.74($1.38 per serving)
iHerb
$ 20.74
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Analysis

Biotin leads the formula at a very high supplemental amount, supported by vitamin C and several B vitamins. Zinc and copper contribute to normal tissue maintenance, though zinc sulfate and cupric oxide are not premium forms.

Evening primrose oil is the largest specialty ingredient and supplies gamma-linolenic acid. Hydrolyzed collagen, cysteine, lysine, methionine, and hyaluronic acid appear in token amounts that are unlikely to match dedicated products.

The two-capsule serving provides only fifteen days, making long-term use less economical. It best fits users who specifically want high biotin and evening primrose oil, not those seeking meaningful collagen.

Who is it for
  • Adults specifically seeking high-dose biotin
  • Users interested in evening primrose oil
  • People with clinician-reviewed hair nutrient needs
Best for
  • Biotin-focused hair and nail support
  • B-vitamin and trace-mineral coverage
  • Short-term targeted use

Pros

  • High biotin amount
  • Substantial evening primrose oil
  • Includes zinc and copper
  • Provides vitamin C and several B vitamins

Cons

  • Only fifteen servings
  • Collagen amount is very small
  • Hyaluronic acid and amino acids are token doses
  • Mineral forms are not premium

Warnings

  • High-dose biotin can distort thyroid, hormone, and cardiac laboratory tests; follow testing instructions about stopping it
  • Evening primrose oil may increase bleeding risk with anticoagulant or antiplatelet medicines
  • People with seizure disorders should discuss evening primrose oil with a clinician
  • Copper intake should be reviewed before stacking with another hair formula

Nutrient quality

56 Moderate impact

The ingredient selection closely fits hair and nail support, with high-dose biotin as the main strength. Weak copper form and token structural ingredients sharply limit nutrient depth.

Ingredient transparency

82 Highest impact

Every active amount is disclosed without a hidden blend. Collagen source, some nutrient forms, detailed use, and inactive ingredients remain incomplete.

Customer satisfaction

71 High impact

The aggregate rating is strong and supported by extensive feedback volume. No detailed comments are supplied to show recurring benefits or tolerance concerns.

Value for money

41 Lower impact

High-dose biotin and evening primrose oil support part of the premium price. Token structural ingredients and a high serving cost make category value weak.

Report analysis

Goals

Nail Health
Impact
High effect
B Goal FitC+ Strength of SupportC+ CoverageB Formula Quality
Collagen · 100 mgBiotin · 5000 mcgMethionine · 10 mg

High-dose biotin provides the clearest nail-health contribution and is paired with vitamin C, zinc, hydrolyzed collagen, cysteine, and methionine. The combination addresses keratin production, connective tissue support, and several structural inputs.

Collagen and the sulfur amino acids appear only in trace amounts, so most of the practical value rests on biotin rather than the broader formula. The 5,000 mcg biotin amount can interfere with some thyroid, hormone, and cardiac laboratory tests, so the testing team should be told before blood work.

Study evidence
Biotin Supportive 8 studies
Collagen Supportive 4 studies
Vitamin C Supportive 1 study
Zinc No effect 1 study
Hair Health
Impact
Moderate effect
B+ Goal FitD- Strength of SupportC CoverageC+ Formula Quality
Biotin · 5000 mcgZinc · 5.5 mgMethionine · 10 mgLysine · 10 mgVitamin C · 90 mgCollagen · 100 mg

High-dose biotin, hydrolyzed collagen, sulfur amino acids, zinc, copper, and vitamin C are directly selected for hair structure and growth support. Biotin reaches 5000 mcg, but collagen is only 100 mg and cysteine, lysine, and methionine are only 10 mg each.

The formula covers biotin status, structural protein, keratin-related amino acids, minerals, and antioxidant cofactors. Breadth is mostly label-level because the collagen and amino-acid contributions are token. The 5000 mcg biotin amount can interfere with some thyroid, hormone, and cardiac laboratory tests.

Study evidence
Biotin Supportive 4 studies
Collagen Supportive 3 studies
Copper Adverse 4 studies
Lysine Supportive 1 study
Vitamin C Mixed 5 studies
Zinc Supportive 22 studies

Ingredients

IngredientAmount per serving
Vitamin C (Ascorbic Acid)
90 mg
Thiamine (Thiamine Mononitrate)
6 mg
Riboflavin
6.5 mg
Vitamin B6 (Pyridoxine Hydrochloride)
5.1 mg
Folate
680 mcg DFE
Biotin
5000 mcg
Pantothenic Acid (D-Calcium Pantothenate)
5 mg
Zinc (Zinc Sulfate)
5.5 mg
Copper (Cupric Oxide)
2.7 mg
Evening Primrose Oil (Gamma-Linolenic Acid)
880 mg
Collagen, Hydrolyzed
100 mg
L-Cysteine
10 mg
L-Lysine (L-Lysine Hydrochloride)
10 mg
L-Methionine
10 mg
Hyaluronic Acid (Sodium Hyaluronate)
1 mg
Gluten Free Adults 18–50 Dairy Free
Report overview
Biotin · 5000 mcg OverallScore82
B- Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyC Value

The disclosed biotin dose reaches the preferred high-potency range for focused hair and nail support. The label does not confirm d-biotin, while the capsule format offers practical delivery. High-dose biotin can interfere with certain laboratory tests, so use should be disclosed before blood testing.

Methionine · 10 mg OverallScore55
A- Active Ingredient Quality & BioavailabilityF Dose, Safety & Label TransparencyF Value

The label uses the preferred L-form and clearly states its amount. The amount is minimal for methionine-focused hair support, and the serving cost is high for that contribution. Most of the formula value comes from evening primrose oil, biotin, and other hair-focused nutrients rather than methionine. The high biotin amount can interfere with some thyroid, hormone, and cardiac lab tests unless the testing team knows about its use.

F Active Ingredient Quality & BioavailabilityD Dose, Safety & Label TransparencyF Value

Cupric oxide is clearly disclosed but has very poor absorption compared with chelated or organic copper forms. The amount is still within a safe supplemental range, although the zinc-to-copper balance is lower than the preferred range. The multinutrient formula may add broader benefits, but its premium per-serving cost is difficult to justify from the copper component.

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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 participantsHair 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. Menkes disease and response to copper histidine: An Indian case series.
    Yoganathan S; Sudhakar SV; Arunachal G; Thomas M; Subramanian A; George R; Danda S · Annals of Indian Academy of Neurology · 2022
    Case series4 participantsHair Health forCopper
  5. Trace element levels in alopecia areata.
    Bhat YJ; Manzoor S; Khan AR; Qayoom S · Indian journal of dermatology, venereology and leprology · 2009
    Case-control study100 participantsHair Health forCopper
  6. UV damage to hair and the effect of antioxidants and metal chelators.
    Millington KR; Marsh JM · International journal of cosmetic science · 2021
    In vitro / ex vivo studyHair Health forCopper
  7. 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
  8. 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
  9. Brittle nails: response to daily biotin supplementation.
    Hochman LG; Scher RK; Meyerson MS · Cutis · 1993
    Case series35 participantsNail Health forBiotin
  10. Low serum biotinidase activity in children with valproic acid monotherapy.
    Schulpis KH; Karikas GA; Tjamouranis J; Regoutas S; Tsakiris S · Epilepsia · 2001
    Clinical trial125 participantsHair Health forBiotin
  11. 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
  12. 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
  13. 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
  14. Preserving fibre health: reducing oxidative stress throughout the life of the hair fibre.
    Marsh JM; Davis MG; Lucas RL; Reilman R; Styczynski PB; Li C; Mamak M; McComb DW; Williams RE; Godfrey S; Navqi KR; Chechik V · International journal of cosmetic science · 2016
    In vitro / ex vivo studyHair Health forCopper
  15. Causes of hair loss and the developments in hair rejuvenation.
    Rushton DH; Norris MJ; Dover R; Busuttil N · International journal of cosmetic science · 2010
    Narrative reviewHair Health forLysine
  16. 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
  17. 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
  18. 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
  19. 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
  20. 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
  21. 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
  22. 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
  23. 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
  24. 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
  25. 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
  26. 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
  27. 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
  28. 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
  29. 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
  30. Nail Supplements: When, How, and Why?
    Zaraa I; Richert B · Skin appendage disorders · 2026
    Narrative reviewNail 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