Curcumin is a lipophilic polyphenol derived from the plant Curcuma longa and is considered its most important bioactive component. Although a traditional healing agent in Eastern medicine, only in the last few decades it has captured the attention of scientists around the world due to its exceptional biological effects. Curcumin has a pleiotropic effect and has the ability to act on many molecular and signaling pathways of the human organism. Curcumin acts as an antioxidant, anti-inflammatory, immunomodulatory, antitumor, neuroprotective, antiviral, antimicrobial and hepatoprotective agent, and numerous other biological effects are attributed to it. Although proven in vitro, the curcumin's mechanisms of action in the human body have not yet been fully explained, therefore one of the newer hypotheses is that the interaction of curcumin with the gut microbiota could play an important role in its biological effect. Although this nutraceutical has a very high therapeutic potential based on the results of numerous in vitro and in vivo studies, due to its lipophilic nature it is almost insoluble in water and has very low bioavailability, especially when administered orally. Recently, the efforts of science, in addition to elucidating the exact mechanisms of action of curcumin, have also been focused on increasing its bioavailability, and great progress in this field was achieved with the discovery of nanotechnology and its implementation in biomedical sciences. Today, in addition to the biological effects, and especially the antitumor effect, different formulations of curcumin are being researched, in order to improve the bioavailability of curcumin but also to enhance its biological effects without excessive dose increase. The purpose of this review is to provide a brief overview of recent scientific research and new knowledge about curcumin, its bioavailability and available formulations and to provide scientifically supported evidence of its biological effects and benefits for human health