The common succulent houseplant known as Aloe vera has been used (both wisely and unwisely) for all kinds of maladies, from reducing pain in burns to relieving constipation. Some of these treatments may actually work, based on the hygroscopic property of Aloe vera gel [source: Mayo Clinic]. What does that mean, exactly?
Remember how the oleic and stearic acids found in mango butter had a hydrophilic property, meaning it was attracted to water molecules? Aloe vera gel is similar, but it actually attracts water molecules to itself. This makes aloe gel hygroscopic -- it strips water vapor from the air around it.
If the aloe gel is applied to dry, chapped lips, its hygroscopic property attracts moisture to the lips, making it a humectant. Aloe also serves as a great delivery vehicle for essential oils that may aid in elastin and collagen production, like rosehip oil.