Actually, nothing about keratin supplements for hair growth is not safe. Keratin is a naturally-occurring proteins found in teeth ski, your hair, and fingernails. Heal and the most reliable keratin protein on the market comes from sheep's wool and is used in its normal condition to protect broken hair. Because keratin it is completely normal, it does not cause harm to your wellness or your hair, in fact the framework of your hair sufficient canot also influence to straighten it.