Salam aleikum wa rahmatu Llahi wa barakatu.
In a lot of medicine there are doubtful ingredients which we not know if they are halal or halal, such as gelatine, magnesium stearate,ecc... It is very difficult to know if it is animal or vegetable origin. Is it halal to take it?
We often found them in Muslim countries and sometimes find only ,for some types, medicines from non Muslim country with this doubtful ingredients .

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.

In principle, all things are permissible, as Allah Says (what means): {It is He who created for you all of that which is on the earth.} [Quran 2:29]

If a person is not certain that a medication or any other item includes what is forbidden, then there is nothing wrong in consuming it and using it in accordance with the principle, that it is lawful.

For more benefit, please refer to Fataawa 301753, 263212 and 131643.

Allah knows best.