The title compound, C34H38O8 (systematic name: 5,5′-diisopropyl-2,2′,3,3′-tetramethoxy-7,7′-dimethyl-2H,2′H-8,8′-bi[naphtho[1,8-bc]furan]-4,4′-diol), has been obtained from a gossypol solution in a mixture of dimethyl sulfate and methanol. The molecule is situated on a twofold rotation axis, so the asymmetric unit contains one half-molecule. In the molecule, the hydroxy groups are involved in intramolecular O—H...O hydrogen bonds, and the two naphthyl fragments are inclined each to other by 83.8 (1)°. In the crystal, weak C—H...O and C—H...π interactions consolidate the packing, which exhibits channels with an approximate diameter of 6 Å extending along the c-axis direction. These channels are filled with highly disordered solvent molecules, so their estimated scattering contribution was subtracted from the observed diffraction data using the SQUEEZE option in PLATON [Spek, A. L. (2015). Acta Cryst. C71, 9–18].