[1] Chemically, curcumin is a polyphenol, more particularly a diarylheptanoid, belonging to the group of curcuminoids, which are phenolic pigments responsible for the yellow color of turmeric.

[3] Curcumin was named in 1815 when Henri Auguste Vogel and Pierre Joseph Pelletier reported the first isolation of a "yellow coloring-matter" from the rhizomes of turmeric.

[15][16] Curcumin, which shows positive results in most drug discovery assays, is regarded as a false lead that medicinal chemists include among "pan-assay interference compounds".

This attracts undue experimental attention while failing to advance as viable therapeutic or drug leads,[3][6][17] although some derivatives of curcumin such as EF-24 have seen a significant amount of research.

[27][28][29] Aggarwal's research had focused on potential anti-cancer properties of herbs and spices, particularly curcumin, and according to a March 2016 article in the Houston Chronicle, "attracted national media interest and laid the groundwork for ongoing clinical trials".

[31][33] SignPath Pharma, a company seeking to develop liposomal formulations of curcumin, licensed three patents by Aggarwal related to that approach from MD Anderson in 2013.

[34] Between 2018 and 2023, the FDA issued 29 warning letters to American manufacturers of dietary supplements for making false claims of anti-disease effects from using products containing curcumin.

[35] Though there is no evidence for the safety or efficacy of using curcumin as a therapy,[3][6] some alternative medicine practitioners give it intravenously, supposedly as a treatment for numerous diseases.

[36][37][38] In 2017, two serious cases of adverse events were reported from curcumin or turmeric products—one severe allergic reaction and one death[36]—that were caused by administration of a curcumin-polyethylene glycol (PEG40) emulsion product by a naturopath.

[39][40] Ionizing radiation treatment can be applied to either raw materials or ready to eat foods, with some countries, like the United States, imposing limitations on its use.

Carmine samples were quite stable against radiation treatment, annatto showed limited stability, and curcumin was found to be unstable, particularly when diluted.