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Fast-Acting Joint Formula

Life Extension
4.6
★ ★ ★ ★ ★
(697 ratings)
Keratin 300 mg
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Score77
A good branded keratin form is easy to take, but its moderate dose sits inside a formula designed mostly for joints.
How scoring works
Quantity:30 Capsule(s) • (30 servings)
Goals:
Hair Health
Nail Health

Score 77

A good branded keratin form is easy to take, but its moderate dose sits inside a formula designed mostly for joints.
How scoring works
$29.25($0.97 per serving)
iHerb
$ 29.25
Vitacost
$ 29.25
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Analysis

The 300 mg Cynatine FLX amount provides a specialized solubilized keratin source in one capsule. Processing quality is a meaningful advantage over generic keratin powder, even though the amount is not full strength.

Hyal-Joint Complex and standardized Angelica gigas extract appear selected for joint comfort. Neither meaningfully broadens nutrient coverage for hair growth or nail quality, so the formula’s beauty positioning is limited.

Clear amounts and a one-capsule serving support easy use. It is most logical for someone already choosing the joint formula who also values keratin, rather than for a buyer comparing targeted beauty supplements.

Who is it for
  • Adults seeking a joint-first formula
  • People interested in solubilized keratin
  • Users wanting one-capsule convenience
Best for
  • Joint support with incidental keratin
  • Moderate keratin supplementation
  • Simple fixed-dose routines

Pros

  • High-quality Cynatine FLX form
  • Clear active-ingredient amounts
  • Convenient one-capsule serving

Cons

  • Keratin amount is below a full target
  • Supporting ingredients are not beauty focused
  • Limited value as a dedicated keratin product

Warnings

  • Angelica gigas may increase bleeding tendency with anticoagulant or antiplatelet medicines.
  • Avoid the concentrated Angelica extract during pregnancy or breastfeeding unless specifically cleared by a clinician.
  • Unknown keratin sourcing may conflict with animal allergies or dietary preferences.

Nutrient quality

85 Highest impact

Ingredient forms and dosing are well aligned with the intended use. The focused formula avoids obvious excesses and low-value additions.

Ingredient transparency

80 Highest impact

Most active amounts are disclosed and core ingredients are identifiable. Missing serving, blend, or excipient details keep the label from being fully transparent.

Customer satisfaction

70 High impact

The aggregate rating is strong and supported by a useful volume of ratings. Specific feedback was not supplied, so recurring complaints and purpose fit remain uncertain.

Value for money

71 High impact

The core formula offers acceptable value, but serving efficiency is only moderate. Weak extras or category competition reduce the practical return.

Report analysis

Goals

Hair Health
Hair Health
Impact
High effect
A- Goal FitB Strength of SupportC CoverageD Formula Quality
Keratin · 300 mg

Branded solubilized keratin supplies a direct structural hair protein in a clearly stated amount. The amount is moderate rather than full strength, but the specialized form supports better confidence than generic keratin.

The remaining ingredients are designed mainly for joint support and add little reliable help for hair growth or shedding. The formula therefore has useful structural depth but weak coherence as a dedicated hair supplement.

Study evidence
Keratin Disputed 14 studies
Nail Health
Nail Health
Impact
Moderate effect
C+ Goal FitB+ Strength of SupportD CoverageD- Formula Quality
Keratin · 300 mg

Solubilized keratin provides a direct structural protein source that may support nail strength. The surrounding hyaluronic-acid and angelica ingredients are intended for joints and add little nail-specific evidence.

The keratin amount and branded form are clearly stated, although direct nail research for this dose is limited. Most of the formula is unrelated to the selected goal, which weakens its practical focus.

Study evidence
Keratin Adverse 7 studies

Ingredients

IngredientAmount per serving
Hyal-Joint Complex
40 mg
Decursinol-50 Angelica gigas Nakai extract
200 mg
Cynatine FLX
300 mg
Adults 18–50
Report overview
Keratin · 300 mg OverallScore77
A+ Active Ingredient Quality & BioavailabilityC+ Dose, Safety & Label TransparencyD+ Value

The branded Cynatine FLX form offers a meaningful quality advantage over generic keratin. Its clearly disclosed amount is moderate and falls short of the full daily target. The serving price is close to the category norm, so value is balanced rather than exceptional.

View ingredientView products
Loading alternative details
88 Performance

Hydrolyzed Keratin

Doctor's Best
<p>Its label clearly provides 500 mg of KeraGLO as Keratin, Hydrolyzed, making it a more clearly defined keratin option. Compared with the original, its ingredient and goal alignment is stronger, although the input does not provide independent testing or absorption evidence.</p>
65 Performance

Keratin Hair Booster

Reserveage Nutrition
<p>Its label clearly provides 18mg NE of Vitamin B3 as Niacinamide, making it a more clearly defined keratin option. Compared with the original, its ingredient and goal alignment is stronger, although the input does not provide independent testing or absorption evidence.</p>
81 Performance

Hair Skin & Nails Collagen Plus Formula

Life Extension
<p>Its label clearly provides 18mg NE of Niacin as Niacinamide, making it a more clearly defined keratin option. Compared with the original, its ingredient and goal alignment is stronger, although the input does not provide independent testing or absorption evidence.</p>
76 Budget

Keratin 50 mg

Swanson
<p>Its label clearly provides 50 mg of Keratin as Tibetan Wool, preserving relevant keratin coverage. Compared with the original, it lowers the serving cost, although the input does not provide independent testing or absorption evidence.</p>
77 Budget

Hair Ultra Softgels

OLLY
<p>Its label clearly provides 20 mcg of Vitamin D as Cholecalciferol, preserving relevant keratin coverage. Compared with the original, it lowers the serving cost, although the input does not provide independent testing or absorption evidence.</p>
70 Budget

Hair Skin & Nails

Bluebonnet Beautiful Ally
<p>Its label clearly provides 25 mg of Coenzyme Q-10 as Ubiquinone, preserving relevant keratin coverage. Compared with the original, it lowers the serving cost, although the input does not provide independent testing or absorption evidence.</p>
65 Value

Keratin Care

Bluebonnet Beautiful Ally
<p>Its label clearly provides 750 mcg of Vitamin A as Vitamin A Palmitate, keeping the formula relevant to keratin. Compared with the original, the somewhat higher serving cost and ingredient detail create a useful quality-to-cost balance, although the input does not provide independent testing or absorption evidence.</p>
68 Value

Keratin Hair Booster

Reserveage Nutrition
<p>Its label clearly provides 18mg NE of Niacin as Niacinamide, keeping the formula relevant to keratin. Compared with the original, the somewhat higher serving cost and ingredient detail create a useful quality-to-cost balance, although the input does not provide independent testing or absorption evidence.</p>
66 Value

Tres Beauty 3

Reserveage Beauty
<p>Its label clearly provides 18mg NE of Niacin as Niacinamide, keeping the formula relevant to keratin. Compared with the original, the somewhat higher serving cost and ingredient detail create a useful quality-to-cost balance, although the input does not provide independent testing or absorption evidence.</p>
Report alternatives

Sources

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

  1. The Effects of an Oral Supplementation of a Natural Keratin Hydrolysate on Skin Aging: A Randomized, Double-Blind, Placebo-Controlled Clinical Study in Healthy Women.
    Tursi F; Nobile V; Cestone E; De Ponti I; Lepoudere A; Sergheraert R; Soulard JP · Journal of cosmetic dermatology · 2025
    Randomized trialHair Health Nail Health forKeratin
  2. Halloysite/Keratin Nanocomposite for Human Hair Photoprotection Coating.
    Cavallaro G; Milioto S; Konnova S; Fakhrullina G; Akhatova F; Lazzara G; Fakhrullin R; Lvov Y · ACS applied materials & interfaces · 2021
    In vitro / ex vivo studyHair Health forKeratin
  3. Annurca Apple Nutraceutical Formulation Enhances Keratin Expression in a Human Model of Skin and Promotes Hair Growth and Tropism in a Randomized Clinical Trial.
    Tenore GC; Caruso D; Buonomo G; D'Avino M; Santamaria R; Irace C; Piccolo M; Maisto M; Novellino E · Journal of medicinal food · 2018
    Randomized trialHair Health forKeratin
  4. Keratin/alginate hybrid hydrogels filled with halloysite clay nanotubes for protective treatment of human hair.
    Cavallaro G; Caruso MR; Milioto S; Fakhrullin R; Lazzara G · International journal of biological macromolecules · 2022
    In vitro / ex vivo studyHair Health forKeratin
  5. Patient Satisfaction and Adverse Effects Following the use of Topical Hair Fiber Fillers.
    Babadjouni A; Juhasz M; Pham C; Csuka E; Hedayati B; Evron E; Mesinkovska NA · International journal of trichology · 2024
    Cross-sectional study40 participantsHair Health forKeratin
  6. Comparative Analysis of Type I Keratin Expression By Nail Consistency: An Immunohistochemistry Study.
    Mingorance Álvarez E; Rodríguez-León J; Pérez Pico AM; Mayordomo R · Applied immunohistochemistry & molecular morphology : AIMM · 2022
    Cross-sectional study32 participantsNail Health forKeratin
  7. Exposure to toxic agents alters organic elemental composition in human fingernails.
    Schumacher E; Dindorf W; Dittmar M · The Science of the total environment · 2009
    Cross-sectional study120 participantsNail Health forKeratin
  8. Human keratin diseases: hereditary fragility of specific epithelial tissues.
    Corden LD; McLean WH · Experimental dermatology · 1997
    Narrative reviewNail Health forKeratin
  9. Phenotype and genotype features of Vietnamese children with pachyonychia congenita.
    Chu HT; Dinh Duong TA; Le DH; Le TV; Nguyen BB; Dang CV; Vu QV · Pediatrics and neonatology · 2023
    Case series7 participantsNail Health forKeratin