Answered by Ustadh Salman Younas
Question: Would it be haram to use products that contain stearic acid (and its derivatives such as sodium stearate, magnesium stearate, etc) that is derived from pork? Would it be permissible to use soap, shampoo, deodorant, etc in which the manufacturer may have used pork in manufacturing?
Answer: wa `alaykum assalam
Stearic acid can be derived from animal or non-animal source. In both cases, it would be permissible to use a product that contains it, such as soap, shampoo, and deodorants, due to its having undergone an essential chemical change.
However, it would remain still remain superior to use a product that is made from only permissible sources.
Checked & Approved by Shaykh Faraz Rabbani.