Two experiments were carried out. In both experiments, Nile tilapia fry (0.1 g initial bodyweight) were stocked into glass aquaria at 100 fry / aquarium in duplicate aquaria / treatment. The experimental diets were offered daily at a feeding rate of 10 % of the fish biomass for 21 days (hormone-treated diets as commercially done for sex reverse) followed by 8 or 12 weeks as experimental periods in the 1^st and the 2^nd experiments, respectively. Bio-Mos® and T-Protphyt 2000 were added to the 1^st and the 2^nd experiments, respectively at graded levels. The results obtained revealed no significant (P≥0.05) differences among treatments in both experiments concerning growth performance and chemical composition of the fish (except final length and fat % in both experiments, ash % in the 1^st experiment and dry matter % in the 2^nd experiment). However, the diet containing testosterone alone in the 1^st experiment(T₄) and that containing T-Protphyt 2000 at 4 g / Kg diet in the 2^nd experiment reflected the best growth performance. The significant (P≤0.05) values in both experiments concentrated mainly in water holding capacity (WHC, where all treatments were higher than the control) and testosterone (the control was the highest). There were positive as well as negative correlations between the physico-chemical characteristics of the fish carcasses. In conclusion, we could recommend the use of 17 α-methyl testosterone at 60 mg / Kg diet for sex reverse during the early stage after the hatch and to increase the growth and survival besides decreasing fat content without any danger from the hormone residues. The dietary inclusion of Bio-Mos® was not beneficial, whereas the dietary inclusion of T-Protphyt 2000 at 4 g / Kg diet was positively effective in increasing the growth performance of the tilapia fry.