Extensions or synthetic hair integrations add volume and length to an individual's own hair. Extensions have been used mostly by celebrities for more than 30 years, however, due to recent innovations and demand hair clip extensions are now being used by people of all economic classes. The primary methods used in adding these extensions are Tape in, clip in or clip on, fusion, and weaving.

Tape in – This method is the fastest method for adding extensions as it can generally be accomplished in about 30 minutes. The tape in hair extensions will last an average of eight weeks and one's hair can be washed and combed as usual. The best way to brush or comb hair with extensions is to place the brush or comb at the point where the extensions start and gently stroke in a downward motion. In addition, the use of quality shampoos and conditioners is recommended to keep in tip-top condition. Removal of tape in extensions is easily done with the application of glue remover. To add back in simply use glue tape or a liquid adhesive.

Clip-in or clip-on – This method is very effective with fewer disadvantages than other methods and is also the least permanent method. The hair wefts (or weaves) have small clips sewn at the top. Each weft contains about eight sections of hair human in lengths from two inches to ten inches. Adding clip in hair extensions is easy and can be done alone but help from a second person will ensure an even application. To add in clip extensions, the hair is sectioned starting at the nape of the neck. The weft is placed in the first section with the clip open and facing toward the scalp and then firmly snapped into position. The procedure is repeated until all sections of hair have clips added. These types of hair extensions may be worn all day but must be removed before retiring to bed.

The most sought after and available form of hair extension is referred to as premium hair. It is sold at beauty supply shops and online. Premium hair is available in numerous hair types, extensions types, colors, style, and lengths. The two types of premium hair are regular and tangle-free. Regular premium hair is the least expensive of the two, the hair cuticles are present and the wefts tend to tangle easily. The tangle-free premium hair is as stated, tangle-free, due to the removal of the cuticles using an acid bath. In both types, a laminate is applied to give the wefts the appearance of natural hair.