The present mixed-method longitudinal study examines students' experiences of study-related exhaustion, regulation of learning, peer learning and peer support during university studies. At the first measurement point, 188 first-year students completed the questionnaire. At the second measurement point, 91 of the 188 students participated in the follow-up study at their fourth study year and completed the same questionnaire again. Of these, twelve students were interviewed. The results showed that experienced study-related exhaustion and self-regulation of content increased during studies. However, the results also showed a large individual variation in experienced study-related exhaustion. The students whose exhaustion decreased described experiences of peer support that helped them to develop their self-regulation skills. Students whose study-related exhaustion remained low evaluated their self-regulation skills as good. They experienced that they did not need other students' support in the regulation of learning. The students whose study-related exhaustion increased or remained high described more problems in self-regulation. Most students relied on peer support because of self-regulation problems. However, not all students used other students' support despite of problems in studying. It can be concluded that regulation skills have a key role in experienced study-related exhaustion during studies.