The main addictive component of tabacco is nicotene which naturally occurs in the tobacco leaves. That’s why tribes in places where tobacco grew wild chewed the leaves and started drying them for smoking in the first place hundreds of years ago. Tobacco companies do add other stuff. Mainly the other stuff is filler to make the cigarettes cheaper to make and to make the tobacco go farther (make more cigs from an ammount of tobacco). They also add stuff as a preservative so the cigs burn well for a longer period of time. You’ll never get a straight answer from the companies as to what is in their products as those are trade secrets.