Called 'base-ring juglets', vessels of this sort have long been believed to have links with opium use since when inverted they bear a resemblance to the seed head of the opium poppy. They are known to have been commonly traded in the eastern Mediterranean ca. 1650 - 1350BC
Instruments from the Centre of Excellence in Mass Spectrometry at the University of York were used to develop a new analytical method, since to conclusively detect the alkaloids and demonstrate the incidence of opiates in the oil-based residue of the vessel.
Earlier, it has been claimed that these juglets could have been used to hold poppy seed oil, comprising traces of opium, used for anointing or in a perfume. In this theory, the opium effects may have held symbolic significance.