Moringa oleifera leaves, seeds, pods, roots, and flowers have been widely used for their medicinal and nutritional properties. Many studies have been conducted on the chemical composition and effectiveness of M. oleifera. In fact, almost every part of M. oleifera has been found to contain essential nutrients and medicinal value. Especially, the leaves of M. oleifera are known to have various nutrients and diverse efficacy. Several studies have assessed the potential toxicity of the leaves when prepared by various methods. The results showed that the M. oleifera leaves when prepared differently were safe in locally used doses and amounts. Moreover, M. oleifera is known to contain various physiological efficacies, including antioxidant, anti-inflammatory, antidiabetic, and anticancer effects and so on. In the latest research, many attempts are being made to utilize the diverse effects of M. oleifera. This research seems to be bringing a promising view of M. oleifera as a therapeutic functional food for various diseases.