'contradictory effects' is a correct and usable phrase in written English.
You can use it to describe when two different effects occur at the same time and are seemingly at odds with each other. For example: "The new medication had contradictory effects, relieving pain in some cases while exacerbating it in others."
In the long term the contradictory effects of risk behavior and effective therapy are still poorly understood.
Subsequently, we study scenarios to assess the contradictory effects of risk behavior and effective therapy, by varying corresponding values of parameters.
While much of the prescriptive literature has advocated the strategic HRM role (Truss 2009a; Ulrich 1998), the evidence concerning the degree of implementation or effectiveness in public service organizations suggests more complex and partly contradictory effects of HRM-based reforms.
Our eyes revel in contradictory effects that baffle our rational minds.
By "taking the gun out of politics", the EU has contradictory effects.
The fact that serotonin has varied and sometimes contradictory effects scarcely matters here: Peterson's story about the lobster is essentially a modern myth.
When a nation large or small suffers a human and geopolitical catastrophe, that has multiple and often contradictory effects on its faith and culture.
The style of theatre that Piscator propounded, using montage and juxtaposition of short independent scenes to create dialectical and often contradictory effects, he called epic theatre.
In contrast, nitrogen supplementation had contradictory effects.
An elevated working temperature exerts two contradictory effects on the size of resultant nanofibers.
Despite their potent anti-inflammatory activity, contradictory effects of glucocorticoids were observed during saccular lung development.
