Onion skin is one of the causes of waste in Brebes Regency. Handling shallot skins can be done by utilizing them as feed additive for ducks, which are also commonly encountered. Onion skin contains active compounds such as flavonoids, terpenoids, and phenols, which can act as an antibacterial and as an alternative herbal feed additive replacement for antibiotics. Shallot skin contains compounds that can reduce cholesterol levels. This study aims to analyze the addition of shallot skin waste flour in feed to see the level of cholesterol (LDL) reduction in the blood of Tegal ducks and their hemoglobin levels. The study was conducted using a completely randomized design with a single factor with three levels of treatment and repetition. The results of the addition of shallot skin waste flour showed a significant reduction in blood cholesterol levels in Tegal ducks. The results showed that the average cholesterol level for the first treatment was 9.8 mg/dl, the second treatment was 3.4 mg/dl, and the third treatment was 1.3 mg/dl. The lowest cholesterol content was found in ducks with the addition of 30% shallot skin flour feed.