Know of any natural pain killers for internal pain?

For "internal pain" - God's Word, the Bible.
It works for me.

Yes I find great comfort in God’s Word.

This certainly helps to relieve the pain.

“Blessed be . . . the Father of tender mercies and the God of all comfort, who comforts us in all our tribulation. . . . Now whether we are in tribulation, it is for your comfort and salvation; or whether we are being comforted, it is for your comfort that operates to make you endure the same sufferings that we also suffer. And so our hope for you is unwavering, knowing as we do that, just as you are sharers of the sufferings, in the same way you will also share the comfort.” Says 2 Corinthians 1:3-7.

The apostle Paul counseled Christians to throw their anxieties on Jehovah through prayer.

With what result? “The peace of God that excels all thought will guard your hearts and your mental powers by means of Christ Jesus.”—Philippians 4:7.

What is this “peace of God”? It is a calmness that comes from having a close relationship with the Creator. Such intimacy gives us confidence that, regardless of our distresses, Jehovah “will not abandon his people; he will not desert those who belong to him.”—Psalm 94:14


God’s Word, the Bible, promises that Jehovah “will wipe out every tear from their eyes, and death will be no more, neither will mourning nor outcry nor pain be anymore.” (Revelation 21:3, 4)

Not all people have this comfort and knowledge though…
Isaiah 65:13, 14 -

“ Therefore this is what the Sovereign Lord Jehovah has said: “Look! My own servants will eat, but YOU yourselves will go hungry. Look! My own servants will drink, but YOU yourselves will go thirsty. Look! My own servants will rejoice, but YOU yourselves will suffer shame. Look! My own servants will cry out joyfully because of the good condition of the heart, but YOU yourselves will make outcries because of the pain of heart and YOU will howl because of sheer breakdown of spirit”