Varenicline is used along with education and counseling to help people stop smoking. Erythrosine B, the food additive has been recently investigated as a fluorescent dye for the determination of drugs. Herein, two new facile methods were examined for varenicline, the smoking cessation aid using this fluorochrome. In the first method; the fluorescence of erythrosine B was quenched by increasing concentrations of varenicline through ion-pair complex formation. This linear response was a basis for the spectrofluorimetric method for varenicline quantitation in pure and dosage forms. The quenching is correlated with the concentration linearly over the range of 0.4-4.0 μg/mL at 550 nm after excitation at 528 nm with a correlation coefficient of 0.9993. Different parameters were investigated to reach the optimal conditions with highest sensitivity and repeatability. The second method is depending on measuring the formed complex spectrophotometrically at 550 nm over the range of 1.0-10.0 μg/mL with excellent correlation coefficient of 0.9999. This ion-pair complex was measured at pH=4 using Britton Robinson buffer. The suggested methods were validated in consistent with ICH guidelines, with acceptable results. The procedures were utilized to test the uniformity of content of Champix tablets. By comparing to previous spectroscopic method; there was no significant difference as revealed from the calculated student t-test and variance ratio F test values.