I'm not sure if anyone has posted about the role of nose breathing as an aid to treatment before. I appreciate this is not technically a supplement but I believe this is worth looking at. This is a quote from an article.....

Nose breathing drives oxygen more efficiently into the lower lobes of the lungs rather than staying in the upper lobes, as with mouth breathing. With nose breathing, all five lobes of the lungs are used to breathe rather than just the upper two. The lower lobes of the lungs have more parasympathetic, calming and repairing nerve receptors, which are activated during nose breathing exercise. The upper lobes have more sympathetic (fight or flight) stress receptors that are activated during mouth breathing exercise.

There are countless videos and articles promoting the benefits of nose breathing, especially while sleeping.

My thoughts are that if we can boost our oxygen supply to our periphery then that goes a long way to towards healing. And by boosting parasympathetic nerves we can only help ourselves. One doctor describes how cold hands become warm.

I've tried to train myself to breathe through my nose especially on my lock down walks and done lots of breathing exercises, (again countless links). There appears to be a lot of evidence supporting benefits. I am looking to see if my cold hands become warm.