A hair unit usually lasts from 1 to 2 year depending on the way, how you maintain it. Your hair system is continuously exposed to direct sunlight, dust, smoke etc, making it look unhealthy. If you want to know how long human hair would last,I just tell you it can last maybe several months ,maybe 1 year,maybe 2 years or more. This is depend on the way you care and maintain your human hair wig.
So you would better to do some right thing to expand your hair life.
Here are some tips for you:
Pre-wash: Before shampooing, gently remove any tangles from your hair products. Always use a mild shampoo or one specifically formulated for chemically treated hair.
Shampoo: Do not soak. soaking might cause the hair to tangle. Once the hair is thoroughly wet, apply a small amount of shampoo; using your fingers, distribute the shampoo evenly throughout the hair.
Wash: Run the hair under warm (not hot) water. Gently work the shampoo into the hair, stroking downwards from the top to the ends. Do not twist, scrub or rub the hair.
Comb: While wet, gently comb the hair to remove tangles. Using a large toothed comb, move in a downward motion away from the clips and to the ends. Do not use a bristle brush on wet hair as it may pull out or break the hair.
Rinse: Rinse the 100 percent human hair wig under a gentle stream of cold water until no shampoo or suds remain. To avoid tangling, ensure the water flows from the cap to the ends of the hair. Remove the excess water by gently blotting with a towel.
Condition: Apply a small amount of conditioner, using your fingers to evenly distribute it throughout the hair.
Dry: Hang to air dry, set in rollers, or use a blow dryer on a low setting, as desired. Your human hair products will not require washing as often as your own hair, wash only when they start to look dull and lifeless.