Because both the application of a juvenile hormone analog, methoprene, and the addition of protein to the adult diet increased the sexual success of male Caribbean fruit fly, Anastrepha suspensa (Loew) (Diptera: Tephritidae), it was hypothesized that both might also impact male nutritional status. Total content of lipid and of protein in A. suspensa males were measured to discover if there was an effect of these treatments alone or in combination on the content of each of these subtstances. In the first 24 hours following adult emergence, 6 different treatments were applied (all possible combinations of methoprene in acetone solution or acetone alone, and protein-diet enrichment). Adult weight was determined for all treatments at 5, 10, 15, 20, 25, 30 and 35 d post-emergence. Dietary protein had a positive effect on the weight and total lipid and protein contents during the first 35 d of adult male life. There were minimal negative impacts from methoprene applications. Even though males were more active sexually, there was no significant change in weight or protein content during the study period. However, total lipid content decreased with age. The usefulness of methoprene to enhance the sexual performance of mass-reared tephritids destined for sterile release appears to outweigh any physiological costs/limitations that such treatment might confer.