To promote nucleation in nanoparticle synthesis, high-power operation is desirable. However, at high power, heat generation due to the rapid microwave absorbance of particles often results in rapid bubble growth, unstable nucleation, and superheating. Therefore, a trade-off between suppressing superheating and producing stable and finer nanoparticles is necessary. This study aims to investigate and confirm the synergistic effect between the high power of microwaves and addition of different types of antisolvents. Results show that the addition of an antisolvent prevents superheating and produces fine-sized particles at high-power operation. In addition, it was observed that glycerin is a better antisolvent than ethylene glycol.