1) In many skincare products like lotion for example, there’s ingredients derived from animals. I believe I read it’s okay to use externally but that product needs to be washed off. If I have a face lotion that contains an animal product, is wudu sufficient to become tahir? And if I for example put lotion on after doing wudu, does that substance invalidate my wudu or make it so that I am unable to pray with it on?

2) Do you know anything about the ingredient “Lanolin” ? I read it’s derived from sheeps wool, does that make it tahir? Or if the animal is alive when the ingredient is taken from them does that effect if it’s halal or not?

3) How do you differentiate between an ingredient that’s gone through a chemical change (making it tahir) and something that remains najis?

1) If you have such products on your face/body then it is best to wash it off first and then perform wudhu. If the lotion has najis products in it then you cannot pray with it on.

2) According to Sayyid Sistani. The wool of the animal is pure, even if it is taken from a dead animal. I do not know about lanolin specifically

3) The establishment of chemical change has to be based on actual fact or information, so for example, a chemist shows that it has in fact converted from one substance to another