I quit smoking twice using medication and both went well. I started smoking for a second time after a few years because stressful circumstances so I had to quit again.

First time I used a drug called Champix that it was eventually retired, that one had a bunch of adverse effects but for the intended purpose it worked like a cheat code.

The second time it was another medication that I never learned its name. That one required a bit of effort but overall it made very easy to resist the urge for smoking. From what I heard this one requires to be below certain level of smoking so a heavy smoker would need to reduce a lot before starting.