Thanks for your interest in our products!
To answer your question, our Curly Hair Custard does work on 4C hair if it is 4C and low porosity. Make sure you are combining it with an oil and use less of the custard because the product can sit on top of 4C hair and dry white and flaky if not combined with an oil.
Hope this was helpful, please let us know if we can help further!
The MopTop Gang :)