Randomized placebo-controlled clinical trial for the assessment of the efficacy of a food supplement in improving hair appearance
Thin, brittle hair that breaks easily
The active intervention consisted of a food supplement containing L-cystine, vitamin C, ceramides, Cotinus coggygria bark extract, zinc, folic acid, and vitamin B12. The placebo consisted of a comparable excipient matrix but did not contain the active ingredients. A restricted randomization list was generated by an independent technician using the appropriate algorithm ("Wei’s urn") of the PASS 11 software (PASS, LLC, Kaysville, UT, USA) and stored in a secure location. The principal investigator or designated study personnel dispensed the study products according to the randomization list. A total of 66 participants were randomized in a 1:1:1 ratio to one of three treatment groups (22 participants per group): Group 1: 2 tablets per day of the active food supplement and 2 tablets per day of placebo food supplement (for a total of 4 tablets per day) Group 2: 4 tablets per day of the active food supplement Group 3: 4 tablets per day of the placebo food supplement The study was conducted using a double-blind design, whereby participants, the principal investigator, and all study personnel involved in the conduct and assessment of the trial remained blinded to treatment allocation throughout the study. Participants received the assigned treatment for 84 ± 2 days.
1. Good general health 2. Caucasian ethnicity 3. Female sex 4. Age between 18 and 60 (+2) years old 5. Thin, brittle hair that breaks easily 6. Agree to not to take any treatment (oral or topic) able to interfere with the hair strength during the whole study duration 7. Willingness not to dye/blench hair during the 2 weeks preceding each visit 8. Willingness not to cut hair for the entire study length 9. Registered with health social security or health social insurance 10. Signed their written Informed Consent form (ICF) and Privacy Policy for their participation in the study and a photograph authorization 11. Able to understand the language used in the investigation centre and the information given 12. Able to comply with the protocol and follow protocol constraints and specific requirements 13. Willingness to take during the entire study period only the product to be tested 14. Willingness not to use/take similar products/food supplement that could interfere with the product to be tested 15. Willingness to not vary the normal daily routine (i.e. lifestyle, physical activity, diet, etc) 16. Under effective contraception (oral/not oral) if women of childbearing potential; not expected to be changed during the trial
1. Do not meet the inclusion criteria 2. Taking part or planning to participate to another clinical study in the same or in another investigation centre 3. Deprived of freedom by administrative or legal decision or under guardianship 4. Admitted to a sanitary or social facilities 5. Planning a hospitalization during the study 6. Under treatment with food supplements which could interfere with the functionality of the product under study 7. Participated in another clinical study with anti-hair loss product or treatment within the last 24 weeks before the inclusion visit 8. Breastfeeding or pregnant or not willing to take necessary precautions to avoid pregnancy during the study (if women of childbearing potential) 9. Has started or changed oestrogen-progesterone contraception or hormonal treatment, within the 3 months prior to the study or foreseeing it for the duration of the study 10. Having an acute, chronic or progressive illness liable to interfere with the study data or considered by the Investigator hazardous for the subject or incompatible with the study requirements 11. Under radiotherapy or chemotherapy at any time 12. Under locally pharmacological/non-pharmacological treatment applied on the area of interest monitored during the test 13. Eating disorders 14. Any other hair disorder or hair disease (female-pattern hair loss, any type of alopecia) 15. Excessive and/or fluctuating hair shedding for more than 6 months 16. History or clinical signs of hyperandrogenaemia 17. Any hair care product applied on the scalp between the last shampoo and the inclusion visit (e.g., gel, hairspray, wax, foam) 18. Scalp surgery (hair transplants, laser) at any time