You absolutely can! I typically use aloe vera gel (this brand) just to extend the shelf life. But if you use fresh aloe vera, you’ll actually find it has stronger healing properties. For fresh aloe vera, harvest it using these instructions, and then blend it with a hand blender to make it smooth for the recipe. You won’t need any preservatives if you use it right away. Store it in the fridge, and toss out any remaining salve after a week or if you notice any funky colouring or odours.