Aromatherapy and Essential Oils What are the contraindications of using biotin Posted on March 29, 2018February 20, 2018 by admin There are no reports of overdose as any excess is excreted in the urine. There are no side effects reported. Related posts: Cognitive Enhancers AP Psych Neurotransmitters/Drugs Psychedelic Drugs What are the contraindications of using biotin