What products should I use, and can I use purple shampoo?

Use a sulfate-free, paraben-free shampoo and a moisturizing conditioner made for extensions. Extension hair can't make its own oils, so sulfates and the harsh ingredients in many drugstore products dry it out fast.

Yes, you can use purple shampoo on blonde extensions. Once a week keeps the tone from turning brassy. Follow with a moisturizing conditioner, because blonde hair is more delicate.

Skip bond-repair treatments like Olaplex and K18. They're made to rebuild damaged bonds in natural hair, and on extension hair they can leave it stiff and dry instead. A deep conditioner and a drop of argan oil on the ends work better.

Want to go deeper? Why You Should Avoid Olaplex and K18 on Hair Extensions