There isn't much material available on how the frogs create their skin secretions. I am reasonably sure that they will create their own toxins, like toads. It is quite interesting that this species is closely related to the "reed frogs" (Hyperolius) and "leaf-folding" frogs (Afrixalus). They use the toxins as a defensive mechanism.

In Mark-Oliver Rodel's book, Herpetofauna of West Africa, mentions another species, Kassina fusca, is associated with the very aggressive ponerine ants. The skin secretions protect the frog from being stung by the ants.