I have noticed headaches and dry mouth recently while trying out new/different flavors with varying % of PG/VG , Some samples/bottles don't show the actual percentage of PG/VG . The nic level of all the new ones is 24mg and I do realize too much can cause headaches but can PG/VG percentage be a factor ? I have noticed extreme dry mouth as well with these assorted 24mg samples. Should I order/purchase a different mix of PG/VG ? I appreciate any advise and the experience & knowledge of fellow members .