Is stimulation of the vagus nerve ever NOT a good idea? Can it exacerbate any conditions?

My biggest concern would be in cases of extremely low blood pressure or heart rate.   And I don't recommend bitters if the gallbladder is removed.  It would also be  a good idea to avoid bitters in cases of peptic ulcers until healed.

I believe you once posted about your reasons for altering your AT formula, but I can't find it with search feature. I have some of your old bulk powder formula (which I recently ordered) as well as some of your new capsules. Why the new ingredients in the capsules, and why did you drop any of the old (like the Siberian ginseng, if I remember correctly)?

I added the Gynostemma (jiaogulan) as a stronger adaptogen.  Because of its extremely bitter taste I did not add it to the powder, especially since a lot of children also take the Adrenal Tonic, especially for allergies/asthma.  Now that it is in capsules I do not have to worry about the taste.  I added ashwagandha for both a more calming effect and for supporting the thyroid more through the adrenals.  The other change was the addition of acerola cherry for a vitamin C source since there is so much debate on the C content of amla.  This way I don't have to explain over and over about the amount of vitamin C compared to vitamin C activity.