Shaykh Ibn Uthaymeen was asked:
“The female questioner says in regards to placing henna, milk, onion, garlic, and other than that of foods that are placed on the head hair. Is there anything wrong with that?
“There is no harm in it. There is no harm for a woman using foods that benefit her hair or her face. However, she does not use something that is impure due to the generality of the verse of the Exalted:
هُوَ الَّذِي خَلَقَ لَكُمْ مَا فِي الأَرْضِ جَمِيعاً
He it is Who created for you all that is on earth. Then He Istawa (rose over) towards the heaven and made them seven heavens and He is the All-Knower of everything
End translation. [Noor ‘ala Darb no. 352]
Faisa Ibn Abdul Qaadir Ibn Hassan