Effectiveness of a food supplement on skin, hair and nail condition

INTERVENTION: The active food supplement intervention (Kera‐Diet®) is a food‐grade hydrolysate of natural keratin that improves hair and nail condition: brightness, volume, density, growth and vitality. It boosts keratinocytes' endogenous glutathione production. It has a traced origin, from a sustainable protein source and it has a stable and unique profile of 17 amino acids, 83.3% in free form. It has a very high assimilation due to a very low molecular weight (100% < 800 Daltons). The Benchmark food supplement intervention is a cosmeceutical ingredient comprised of solubilized keratin, already present in the market, while the placebo food supplement intervention is maltodextrin and magnesium stearate. All the active, benchmark and the placebo products are used as follows: four capsules per day; two capsules in the morning and two capsules in the evening for 90 days. All participants will apply for all the study length a base cream with no cosmetic claim for face care, two times a day (morning and evening). Participants are randomly into four groups of 33 subjects as follows: 1. 30 subjects (33 included) take the active study product with standard concentration (250 mg) 2. 30 subjects (33 included) take the active study product with a lower concentration (125 mg) 3. 30 subjects (33 included) take a reference product already on the market – benchmark 4. 30 subjects (33 included) take the placebo formulation A restricted randomization list is created using PASS 2008 (PASS, LLC. Kaysville, UT, USA) statistical software running on Windows Server 2008 R2 Standard SP1 64‐bit Edition (Microsoft, USA) by a biostatistician and stored in a safe place. The randomization sequence was stratified using “Efron’s biased coin” algorithm with a 1:1 allocation ratio. The allocation sequence was c CONDITION: Visible face roughness and mild to moderate skin slackness, brittle nails and damaged/brittle hair ; Skin and Connective Tissue Diseases PRIMARY OUTCOME: 1. Skin profilometry (Ra parameter, wrinkle depth, wrinkle length and wrinkle area) measured in the “crow’s feet” area) using Primos 3D (GFMesstechnik GmbH) at baseline (T0), 45 days (T45), T90 days (T90); 2. Deep skin moisturization measured using a MoistureMeterEpiD at baseline (T0), 45 days (T45), T90 days (T90); 3. Skin brightness measured using the spectrophotometer/colorimeter CM‐700D (Konica‐Minolta) at baseline (T0), 45 days (T45), T90 days (T90); 4. Skin elasticity and firmness measured using the suction/elongation method and the subsequent release of the skin inside the opening of the instrument (Cutometer®MPA 580, Courage+Khazaka, electronic GmbH) at baseline (T0), 45 days (T45), T90 days (T90) ; 5. Digital pictures acquired by means Visioface (Courage+Khazaka) at baseline (T0), 45 days (T45), T90 days (T90); 6. Skin thickness (epidermis) and fibres analysis (skin density and overall anisotropy score) measured using DeepLive™ (DAMAE Medical) at baseline (T0) and T90 days (T90) SECONDARY OUTCOME: 1. Nails and hair brightness measured using the spectrophotometer/colorimeter CM‐700D (Konica‐Minolta) at baseline (T0), 45 days (T45), T90 days (T90); 2. Clinical evaluation of nail hardness/brightness using VAS score scales at baseline (T0), 45 days (T45), T90 days (T90); 3. Product acceptability and volunteers’ perceived efficacy assessed with a self‐assessment questionnaire at T90 INCLUSION CRITERIA: 1. Healthy female subjects 2. Aged between 35 and 65 years old (50% of participants aged between 35 and 50 years old and 50% of the participants aged between 51 and 65 years old in each study group) 3. Damaged/brittle hair (at least 20% of subjects due to discoloration in each study group) 4. Brittle nails (not related to pathological alterations to the nail plate) 5. Clinically showing visible face roughness (crow’s feet wrinkles) 6. Mild to moderate skin slackness 7. Phototype I to IV (according to Fitzpatrick classification) 8. Registered with health social security or health social insurance 9. Signed their written Informed Consent form (ICF) for their participation in the study and a photograph authorization 10. Able to understand the language used in the investigation center and the information given 11. Able to comply with the protocol and follow protocol constraints and specific requirements 12. Willing to use the same shampo