While Indole-3-Carbinol (I3C) is widely recognized for its potential health benefits, understanding its safety profile and potential toxicity is crucial for responsible research and application. Preclinical studies provide valuable insights into the safe dosage and potential adverse effects of I3C. Extensive preclinical toxicity studies in animal models, involving various routes of administration (oral and intraperitoneal), have helped establish the lethal dose 50% (LD50) values for I3C. These studies indicate that while high doses can lead to adverse effects, including mortality and observable toxic symptoms such as piloerection and conjunctival opacification, there is a significant safety margin at concentrations relevant to therapeutic and research applications. The liver has been identified as a potential target organ for toxicity at very high doses, though other organs showed no gross pathological changes. This detailed analysis of Indole-3-Carbinol toxicity is essential for establishing safe usage guidelines. Importantly, the doses at which I3C exhibits antiviral activity in vitro are significantly lower than those found to cause toxicity in vivo. This suggests that I3C can be considered a safe compound when used at effective concentrations. Human studies have also generally reported good tolerability, with mild gastrointestinal symptoms occurring at higher single doses, which resolve upon dose reduction. For researchers and formulators, careful consideration of dosage is paramount. The data available on Indole-3-Carbinol safety and toxicity supports its use in a controlled manner. NINGBO INNO PHARMCHEM CO.,LTD. is committed to providing high-quality I3C that meets rigorous standards, enabling researchers to explore its therapeutic potential with confidence. Responsible sourcing and adherence to established safety data are key to harnessing the benefits of I3C.