This article presents two longitudinal studies that investigated expertise reversal effects in journal writing. In Experiment 1, students wrote regular journal entries over a whole term. The experimental group received a combination of cognitive and metacognitive prompts. The control group received no prompts. In the first half of the term, the experimental group applied more cognitive and metacognitive strategies in their journals and showed higher learning outcomes than the control group. Towards the end of the term, the amount of cognitive and metacognitive strategies elicited by the experimental group decreased while the number of cognitive strategies applied by the control group increased. Accordingly, the experimental group lost its superiority on learning outcomes. In order to avoid these negative long-term effects of prompts, a gradual and adaptive fading-out of the prompts was introduced in the experimental group in Experiment 2 while a control group received permanent prompts. The results showed that, over the course of the term, the fading group applied increasingly more cognitive strategies while the control group applied fewer and fewer cognitive strategies. Accordingly, at the end of the term, the permanent prompts group showed substantially lower learning outcomes than the fading group. Together, these results provide evidence for an expertise reversal effect in writing-to-learn. The more the students became skilled in journal writing and internalized the desired strategies, the more the external guidance by prompts became a redundant stimulus that interfered with the students' internal tendency to apply the strategies and, thus, induced extraneous cognitive load. Accordingly, a gradual fading-out of the prompts in line with the learners' growing competencies proved to be effective in mitigating the negative side-effects of the provided instructional support.