While there are a few things you can do to prevent sagging skin, and a few that will help saggy skin, an actual home remedy to help sagging skin may be hard to find.
Since the cause of loose and sagging skin is the loss of collagen, elastin and hyaluronic acid, the only real way to fix it is to replenish those lost proteins. This can be hard to do without outside help.
Proper nutrition, exercise and hydration can go a long way to prevent saggy skin, and can even help to reverse loose skin.
Eating a diet rich in fruits, vegetables and whole grains will keep your skin nourished with the vitamins it needs as well as provide some anti-oxidants. Keeping well hydrated will prevent wrinkles and loose skin as well.
Sun damage can also be a major cause of wrinkly sagging skin. Always cover up and use a high SPF sunscreen when you are out in the sun and avoid tanning beds altogether.
UV rays are hard on the skin and cause premature aging of the skin as well as increase your risk of skin cancer.
While not specifically a home remedy to help sagging skin, the best thing you can do is use a good quality anti-aging skin cream every day. Do not be fooled by all of the great looking products on the shelves though. Most of them are completely ineffective and many are even harmful.