It is so food. Tea is food. Comphrey is in my garden along with the other herbals such as parsley, spinach, et al. I eat parsley and celery also for health along with Comphrey tea. I also mix comphrey in green tea. That one eats/drinks certain foods for health doesn't make these herbal foods drugs. I suppose by your token, that some folks eat take chicken soup when they have a cold makes chicken soup a drug.
so what does parsley do to help your health that eating a non-herb wouldn't do? how about spinach? those are foods, they arn't eatten to help heal something, but used to make energy for the body.
something like comphrey or comfrey, has been found to be a drug, it contains substences that are not safe to digest everyday, infact the substence in comfrey has been linked to cancer of the liver and other things
the thing is buz, chicken soup contains nothing we don't know about, while something like comphrey does, we don't know how the plant should be regulated safely as yet, chicken soup contains what? chicken and water?