Nanoparticles serve as a new fertilization method utilised in agriculture, and their potential effect on medicinal crops has been mainly unexplored. In the present study, using ultrasonic irradiations, a novel nano-sized iron complex has been prepared from aminolevulinic acid and iron (III) nitrate under greenhouse conditions. The obtained Fe nano-sized energy dispersive X-ray spectroscopy complex has been characterized by two methods, i.e. Fourier-transform infrared spectroscopy and spectra. The morphology and size of the nano-complex were also determined using transmission electron micrographs and showed an acceptable size in the nano range (5-25 nm). In this work, purslane plants were supplied with Fe (III)-aminolevulinic acid as a new nano-sized complex and Fe-EDDHA. The mineral nutrient concentrations, total phenolic, ascorbic acid contents and antioxidant activity were the highest in the plants treated with the Fe-ALA nano-complex. Catechin was the predominant phenolic compound in all treated plants. The Fe nano-complex at the rate of 0.2% induced extra high-value phenolic compounds. The shoot Fe, Zn, N, Mg, Ca and K contents were also higher in the plants treated with the Fe nano-complex than in both the control group and the plants treated with Fe-EDDHA. In general, the nutritional and pharmaceutical quality of Portulaca oleracea L. improved when using the nano-sized Fe-ALA complex as a new iron source.