Early cancer detection is critical in improving disease management outcomes. Cancer diagnosis presents unique difficulties mainly due to its pathological presentation and poor accessibility that could limit the usefulness of conventional white light endoscopy in early cancer detection. Fluorescence endoscopy has been proven to improve the sensitivity and specificity of early cancer detection. Hypericin (HY) has been found to be superior to 5-aminolevulinic acid (5-ALA) and its ester derivative hexaminolevulinate (HA) as a fluorescence diagnostic agent, hence its development for delivery in vitro and in vivo, is the subject of this review.