This is the extract of the fresh leaves of Boneset (Eupatorium perfoliatum). It has traditionally been used as an anti-viral and diaphoretic, especially for the flu or for any infection with achy muscles.

Fun story - the plant used in this tincture showed up as a volunteer in my garden at my house in Weaverville many years ago. Although it is native to our area, I don’t know of any other plants within 5-10 miles so no idea how it got there - it just decided to show up one day and establish itself!