more people die from aspirin than from dnp. the dangers of dnp are highly overexaggerated due to the mysticism and misinformation that gets repeated until it becomes fact.
it is very, very difficult to die from dnp during the winter, this is coming from someone who has run dosages close to the lethal level. whether it causes any permanent long term damage, i highly doubt it and i haven't noticed any differences in my disposition after cessation of dnp. my only concern would be an insufficient production of energy substrates to fuel brain or nerve cells, however the mode of action for how dnp works is similar to the body being in a severe calorie deficit, which will cause bodily defense mechanisms prioritizing brain and central nervous system function. also considering dnp doesn't completely stop ATP production, you will still produce enough energy to prevent cellular death until you either: approach dosages that will induce rigor mortis or more likely cause a fever that will kill you first.
just don't use this shit during the summer and keep your dosages under a gram and won't feel like you're dying.