 [ Symptoms ] can biotin cause weight gain started taking bioting to improve hair skin and nails but have been reading this causes weight gain is this true [ Disease ] there is no research that biotin causes weight gain weight gain is typically caused by a calorie imbalance and certain medications but not vitamins a balanced diet is more effective than supplements which is explained in this post <link> for more specifics on biotin uses evidence and side effects visit this page <link> no