On average, “the shelf life for essential oils is two to three years,” she says. “Citrus oils such as lemon, sweet orange, and lime are a bit shorter, about one to two years.” “Oils such as Australian sandalwood, vetiver, and patchouli,” she adds, “have a much longer shelf life—up to six years.” This is why it’s important to note the appearance of your oils when you first get them, along with their scent.