A randomized, double-blind, placebo-controlled study evaluating the effects of a polyphenol-rich red and black currant extract combined with biotin on wrinkle morphology, skin surface roughness, and hair shedding
Skin and hair outcomes
Active comparator: polyphenol-rich red and black currant extract combined with biotin Placebo comparator: placebo Subjects were instructed to maintain their usual lifestyle and cosmetic habits throughout the study, while avoiding the use of other products or treatments that could affect the face, hair, or nails. Additional restrictions included avoidance of excessive sun exposure and adherence to standardized conditions prior to each visit, including hair washing and consistent grooming habits. One capsule of 500 mg of the polyphenol-rich extract plus biotin or placebo was orally received daily per subject for a total period of 12 weeks.
1. Healthy female volunteers aged 21 to 65 years 2. Presence of mild to moderate facial wrinkles and skin roughness (grades 1–3 on Eiben-Nielson & Kerscher scale) 3. Moderate to excessive hair shedding (grades 3–6 on Sinclair Hair Shedding Scale), confirmed by combing test 4. Low hair density (grades 3–6 on customized female Ludwig scale) 5. Willingness to maintain usual lifestyle and cosmetic habits during the study 6. Agreement to avoid use of other products or treatments that could affect skin, hair, or nails during the study period 7. Completion of required washout period (≥15 days) for interfering products prior to study start 8. Last participation in another clinical study completed at least 8 weeks prior to enrollment 9. In good general health with no conditions that could interfere with study outcomes 10. Ability and willingness to provide written informed consent
1. Presence of dermatological or systemic conditions that could affect the face, scalp, hair, or nails or interfere with study outcomes 2. Recent aesthetic or dermatological treatments in the study areas (e.g., facial procedures, hair treatments) 3. Use of medications, supplements, or cosmetic products that could influence skin, hair, or nail condition (without appropriate washout) 4. Pregnancy or lactation 5. Known allergy or hypersensitivity to any component of the study product 6. Participation in another clinical study within 8 weeks prior to enrollment 7. Failure to complete required washout period (≥15 days) for interfering products 8. Any medical, psychological, or compliance-related condition that, in the investigator’s opinion, could compromise participation, adherence, or data integrity 9. Inability or unwillingness to follow study procedures and restrictions