I want to know if a face cream/ BB cream which contains allantoin can be used externally? Also, can salah be prayed with it when applied? The product does not specify if the allantoin is animal or plant-based.
بِسْمِ اللهِ الرَّحْمنِ الرَّحِيْم
In the name of Allah, the Most Gracious, the Most Merciful.
Allantoin sourced from the uric acid of urine will be deemed impermissible. Allantoin derived from plants or produce synthetically will be permissible.
Only Allah knows best
Written by Maulana Imran Mughal
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
 Imam Marghaynani, Al-Hidayah (Karachi: Maktabah Al-Bushra, 2014), 1:132.