Let $X$ be a connected space, and let $\lbrace x_\lambda\rbrace$ be a homogeneous basis for $H_\ast(X)$ (as a vector space). H_\ast(X;\mathbb{F}_2)$. Then $$H_\ast(QX) H_\ast(QX;\mathbb{F}_2) = \mathbb{F}_p mathbb{F}_2 [Q^I x_{\lambda} \mid I\mbox{ admissible of excess }e(I)>\mathrm{dim}\,\, x_\lambda ].$$ That is, the homology of$QX$is a polynomial algebra with generators certain iterated Dyer-Lashof Kudo-Araki operations on the basis of the homology of$X$. There is a similar result with coefficients mod$p$,$p$an odd prime, involving Dyer-Lashof operations and the Bockstein operator. (This The situation is reminiscent of Serre's Theorem on the cohomology of Eilenberg-Mac Lane spaces.) The reference for this is (Section 5 of) Dyer, Eldon; Lashof, R. K. Homology of iterated loop spaces. Amer. J. Math. 84 1962 35–88. You will also find a nice discussion in Eccles, P. J. Characteristic numbers of immersions and self-intersection manifolds. Topology with applications (Szekszárd, 1993), 197–216, Bolyai Soc. Math. Stud., 4, János Bolyai Math. Soc., Budapest, 1995. 1 Let$\lbrace x_\lambda\rbrace$be a homogeneous basis for$H_\ast(X)$(as a vector space). Then $$H_\ast(QX) = \mathbb{F}_p [Q^I x_{\lambda} \mid I\mbox{ admissible of excess }e(I)>\mathrm{dim}\,\, x_\lambda ].$$ That is, the homology of$QX$is a polynomial algebra with generators certain iterated Dyer-Lashof operations on the basis of the homology of$X\$. (This is reminiscent of Serre's Theorem on the cohomology of Eilenberg-Mac Lane spaces.)