Overview The beautiful hair models in commercials and glossy magazine advertisements make some women crave long, shiny locks. Other women believe that a healthy, well-kept mane symbolizes youthfulness and offers job security, and they are willing to spend hundreds or even thousands of dollars monthly on haircuts, dye jobs, straightening treatments and other procedures. The Mayo Clinic warns that many of these treatments -- as well as hormonal changes and poor dietary habits -- damage, rather than repair, hair. An easier approach to healthier hair, though, is probably sitting in your refrigerator right now. Step 1 Scoop 1 cup of mayonnaise into a small microwave-safe bowl. Use organic mayo or a homemade recipe to minimize exposure to artificial colors and additives. "Real Simple" recommends stirring in a teaspoon of vanilla extract to neutralize the strong odor of the mayonnaise. Add a dash of olive oil if your hair is very dry or damaged. Step 2 Microwave your mayonnaise mixture on medium for about 10 seconds. Carefully remove the heated mixture from the microwave and stir well. The heat may cause the oils to separate. Step 3 Massage a gentle shampoo into your scalp. Rinse thoroughly with warm water. Toweling dry your hair or gently squeezing the excess water from your strands makes it easier for the mayonnaise mixture to adhere to your hair. Step 4 Apply a generous amount of your mayo mixture, starting at the top of your scalp. Gently rub the mixture into your hair, from the roots to the tips. Focus on the tips and any other dry, damaged areas. The hair that frames your face might also be damaged, as many women straighten, curl or blow dry these strands during their daily beauty routine. Step 5 Place a plastic bag or shower cap loosely over your head and wait for 10 to 15 minutes. Step 6 Rinse your hair with cool water. Hot water can cause the mayonnaise mixture to harden or even cook on your hair. Your hair should feel soft, not greasy. Shampoo again to remove excess mayo, if necessary. Step 7 Repeat this conditioning process once a week, more often if needed. Tips and warnings • Condition with your mayo mixture first, then shampoo hair, if your locks are very damaged. • Individuals with an egg allergy should not use a mayonnaise hair treatment.