system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does "3 in 1" shampoo/conditioner/body wash work?
gpt
They don't work well. 

Shampoos and Body Wash are both variants of soap. They are both designed to strip dirt and oils from the hair and body, though body washes will also normally have an exfoliant in them to help remove dead skin as well. These mixed products tend to have fewer oil removing agents and no exfoliating agents so they do the job of shampoo and body wash more poorly than they would otherwise do. 

Conditioner is designed to add back some of the oils removed from the hair by the shampoo, reduce static as the hair dries, and the like. It does not work at all in the combined products because the shampoo agents just remove anything the conditioner was applying.