This study aims to utilize waste cooking oil to make aromatherapy candles with natural dyes. This study applied a quasi-experimental group with one-group pretest and post-test to test the use of aromatherapy candles in the classroom. There were 30 students from the 4th grade participating. The students’s stress level was measured using DASS which has been modified fitting the students’ condition. We examined the aromatherapy candles. Afterwards, respondents were given treatment, namely relaxation by inhaling for 30 minutes during the learning activities after 1 p.m., then measured stress levels using the DASS (Depression Anxiety Stress Scale) questionnaire before and after treatment. The data showed that based on the test, it concluded that unicorn aromatherapy candles can be used as an effective aromatherapy to reduce the stress level of students in full day school. This product is also safe, affordable, easy to use, smells fresh, no expired date, and helps to raise awareness of love for the environment in the community.