In recent years, a growing global concern has been obesity. Patients with obesity are at major risk for developing several diseases. These diseases may significantly impact patients’ daily lives and increase the mortality rate [1]. Over a year, medication for obesity has undergone substantial changes. An amphetamine-like prescription drug called Phentermine (Adipex-P, Lomaira) appetite. In the last few years, Phentermine and its derivatives have attracted much attention due to their use in weight reduction; by reducing appetite or prolonging the feeling of fullness, it can aid in weight reduction. So, reviewing the synthesis of Phentermine and its derivatives becomes imperative. Therefore, various synthetic routes for Phentermine (from benzaldehyde, isopropyl phenyl ketone, dimethyl benzyl carbinol) and its derivatives synthesis, involving ortho-palladation, are also reviewed here comprehensively.