We construct a nonlinear theory of electric resistance of chiral helimagnets, in which the shape changes and the magnetization spiral starts rotating during the passage of electric current due to the spin transfer torque effect. It is shown that the rotation of the spin spiral under the action of the passing current, the electric resistance of the helimagnet is always lower than the resistance of a helimagnet in which the spin spiral is stationary. It is found that the current–voltage characteristic of the helimagnet in the presence of the spin transfer torque from the conduction electron system to the system of localized electrons can be essentially nonlinear. The possibility of the spin electric bistability effect in helimagnets is predicted for the situation when the spin contribution to electric resistance of a helimagnet can take two different values for the same value of the current passing through it. The possibility of realization of states with a negative differential resistance in helimagnets is demonstrated. © 2023, Pleiades Publishing, Ltd.