Cigarette (physical) detox takes two weeks is pretty much the known standard.
Even when adding nic, there is plenty else to detox from and it's well-known and well-studied that some parts of tobacco (including tar) provide MAOI-A and MAOI-B to the brain. Those are OLD school antidepressants that fell OUT of use (due to side effects, mainly, although there is a newer transdermal patch that relieves a lot of the SCARY DEATHLY side effects) but the dirty little secret about MAOIs is that they are far more effective than say, Prozac. Prozac is far SAFER, and some side effects are easier to handle (though not all, MAOIs don't have sexual side effects for example) but mainly, the MAOIs are for the most part off patent and psychiatrist are loathe to prescribe them due to dangers, not having used them EVER (they really are old), or fears of a lawsuit and whatnot. But, they cannot be beaten for SHEER EFFICACY overall. The reason David Foster Wallace died because he was on an MAOI, couldn't handle the side effects and switched to everything under the sun (including ECT) and then returned to his MAOI, which no longer worked, not unusual as every psychiatric intervention changes the brain in some ways, and eventually committed suicide.
I mention this story as a) he was my favorite author and b) that speaks a little bit to the power of MAOIs. They are not something to be lightly sneezed at.
While it is true that much detox takes place mentally, physical CHANGES to the brain (like quitting) do actually PHYSICALLY change the homeostasis of the brain. By A LOT.
Some folks get through detox, reach homeostasis over time (which actually takes longer than 2 weeks, receptors that have been "fed" MAOIs take time to recalibrate themselves) sometimes longer than two weeks.
Also, many folks start smoking fairly young and may have an underlying depressive or anxiety condition that tobacco was treating. If that is the case, there may need to be some other form of intervention, be it vaping WTA, be it consulting one's doctor, etc. Some people just do fine and transition fairly easily.
But no, cigarette detox is not "all in the mind or head." It is physically (from everywhere) and mentally (dealing with changes in the BRAIN). The brain is not some special organ that is not affected by tobacco, it is affected by tobacco in a MAJOR way, at least for some people.
Being bipolar, I usually find that if I detox off anything (including tobacco) that my brain homeostasis makes it harder. If I had not used WTA I'm not sure I would have gotten through it and even then it was hard. I did not find I needed "extra" MAOI once my brain recalibrated (say, a month or so) but even detoxing from TAR was HARD.
With that said, everyone is different and has to choose their own path. I have noticed some folks are more sensitive than others. The "Why Quit" guy tells this heartwarming tale of just quitting and going to work the next day (cold turkey) and being "functional, but just unhappy." Well, that's fantastic and all, but that was not MY experience. I was pretty ill and off work to begin with, but I quickly realized that to give up tobacco, I was going to have to place that AHEAD of my job and take a leave of absence that ultimately resulted in my not going back to work.
I'm not sorry, either. I will take less income over what COPD was going to cost, any day of the week. I also am not sorry I used WTA. It helped me immensely and all of the above contains the reasons why it did.
Best of luck, whatever you decide.
Anna