How long do extensions last in hair?

Extensions last anywhere from 2-6 months depending on the type and quality. For human hair extensions, the average lifespan is about 3-4 months, although with good proper care and maintenance, like avoiding excessive heat and chemical applications, they can last up to 6 months. Synthetic hair extensions tend to last shorter due to their lower quality, with an average of 2-3 months, but again, good care and maintenance can extend that to 4-6 months.