Efficacy and Safety of L-Cystine Associated or Not to a Natural Keratin (Kera-Diet) Hydrolysate on Hair and Nails: Randomized, Placebo-Controlled, Clinical Trial on Healthy Females

    Vincenzo Nobile, Joel Duperray, Enza Cestone, Renaud Sergheraert, Francesco Tursi
    Image of study
    TLDR L-Cystine and L-Cystine with Kera-Diet® safely improved hair and nail quality in healthy women.
    In a 2019 randomized, placebo-controlled clinical trial involving 60 healthy female subjects with acute telogen effluvium and brittle nail syndrome, researchers found that L-Cystine (CYS) alone or in combination with a natural keratin hydrolysate (Kera-Diet® or KDC) significantly improved hair density, hair and nail brightness, and nail growth rate over a 3-month period. The study reported a 56.9% and 58.9% increase in hair brightness for the CYS and KDC groups, respectively, and a nail growth rate of 0.21 ± 0.02 mm/14 days for the KDC group after 90 days. The treatments were well tolerated with no adverse reactions, and a self-assessment questionnaire indicated a 90% global satisfaction rate for the combination treatment. The study concluded that both L-Cystine and the combination with Kera-Diet® are effective and safe for improving hair and nail parameters in healthy females, offering a beneficial dietary approach for managing symptoms of acute telogen effluvium and brittle nail syndrome.
    Discuss this study in the Community →

    Related Community Posts Join

    6 / 407 results

      community Losing ground after 14 months of fin use and 11 months of min

      in Finasteride/Dutasteride  49 upvotes 2 years ago
      A 24-year-old person who is worried about their hair loss after 14 months of taking finasteride and 11 months of minoxidil. Replies to the post suggested sticking with their current regimen, that shedding from one part may not be telogen effluvium, and that shedding is normal with these drugs and they should evaluate in two to three months.

      community Fighting Hair loss AND Grey Hair

      in Treatment  18 upvotes 2 years ago
      The user is treating hair loss with topical Minoxidil, Finasteride, RU58841, microneedling, and Ketoconazole. For grey hair, they use L-Cysteine, L-Methionine, and PABA, and have noticed some re-pigmentation.

      community Methionine? Glycine?

       6 upvotes 8 years ago
      The conversation discusses the potential benefits and risks of using Methionine and Glycine for hair loss, with concerns about cancer risk if not balanced properly. The user seeks opinions on these amino acids for hair health and overall benefits.

      community Creating the Holy Grail Hair Loss Topical

       1 upvotes 4 years ago
      The conversation is about creating a natural hair loss topical using ingredients like cetirizine, Zinc Sulphate Heptahydrate, Safflower Extract, Ricinoleic Acid, and others. The user is seeking input and collaboration on this topical formula.

      community Nothing's working, I feel depressed, also hopeless for the first time

      in Update  104 upvotes 2 years ago
      A user's experience with hair loss treatments, including Finasteride, Minoxidil, Nizoral Shampoo, Rosemary Oil, Vitamin D, Biotin, Vitamin C, Zinc and Dermarolling, that have not been successful over the past 14 months. Other users gave advice on how to cope with the issue, such as exercising, changing mindset, and shaving their head.

    Related Research

    13 / 13 results