Studies show self-concept highly correlates with mental well-being. Few show self-concept change over time, including the effect of therapeutic interventions and gender differences. Studying how therapy connects with self-concept improvement can lead to improved mental well-being. Over six weeks, 452 college students' self-concept, self-esteem, satisfaction with life, and psychological well-being was measured every two weeks for a total of four times. Self-concept scores were significantly lower for those in therapy than those not. Compared with females, males had a higher self-concept overall but a lower self-concept when in therapy. Those in and out of therapy had an improving self-concept score. Latent class growth modeling identified six trajectory groups for self-concept, where the lower the starting point, the more likely participants were to be in therapy. Future research may investigate the ceiling effect on improvement and extend the study with less frequent testing to better understand long-term self-concept changes in and out of therapy.