The constituent and fatty-acid compositions of neutral lipids (NL), glyco-, and phospholipids and the squalene contents in seeds and the aerial part of Amaranthus retroflexus were studied for the first time. Elaidic acid was observed in all lipid groups. The squalene content was 4.3% of the NL mass in seeds and 3.15% in the aerial part. Preliminary wetting of wheat and cucumber seeds in unsaponified substances, fatty acids, and their methyl esters obtained from A. retroflexus seeds at concentrations 0.001 and 0.0001% was found to reduce the inhibiting action of salt stress. Neutral lipids did not exhibit a protective effect.