An important question is how treatment recommendations would change in the light of our predictions about optimal malaria parasite life histories. Regardless of the life history shifts we predict here, parasite fitness and within‐host densities are reduced by drug treatment. This suggests that despite the evolution of nonclassical resistance, drug treatment offers epidemiological and clinical benefits. Those benefits are not as great as they would be in the absence of life history evolution and, importantly, any hosts that remained untreated could be worse off if drug‐adapted strategies became fixed in the parasite population. Further, as a result of altered patterns of transmission investment, parasites could maintain higher within‐host densities in the face of drug treatment, potentially facilitating the evolution of classical resistance. The theory developed here provides a basis for assessing the constraints and limits on parasite life history evolution in response to human interventions.