Evaluating the Toxicity and Safety of Turmeric (Curcuma longa L.) and Its Components: A Narrative Review

Turmeric (Curcuma longa), a widely used botanical in traditional medicine, has gained global attention for its therapeutic potential, particularly due to its components including curcumin. While its pharmacological benefits are extensively documented, concerns regarding its safety profile and potential toxicity have emerged, especially with high-dose supplementation and long-term use. This narrative review aims to critically evaluate the toxicological evidence and safety considerations surrounding turmeric and its main components. A comprehensive literature search was conducted across PubMed, Scopus, Web of Science, and Google Scholar, covering studies published up to October 2025. In vitro and in vivo studies were carried out to capture a broad spectrum of toxicological data. Toxicological profile of turmeric is influenced by dose, formulation, and metabolic context. Most turmeric-based preparations exhibit low acute toxicity and minimal genotoxic or mutagenic effects under standard conditions. However, high concentrations or certain formulations, particularly crude (unfractionated) extracts, have been reported to induce oxidative stress and DNA damage in vitro, while some nanoparticle systems show mutagenic potential under metabolic activation conditions. In vivo studies generally report favorable safety outcomes, especially for standardized and bioavailable formulations, although some evidence of liver enzyme alterations and histopathological changes has been observed at supratherapeutic doses. Mechanistic insights implicate oxidative stress, mitochondrial dysfunction, and p53-mediated pathways in the observed toxic effects. Turmeric and its components are generally safe when used at recommended doses and in well-designed formulations. However, high-dose or prolonged use may pose hepatic and genomic risks. Refining safety thresholds through harmonized methods and human-relevant models will be the key to guiding their safe and effective clinical application.