Goldenrod is another example of an herb which according to folklore is safe, gentle and good for just about anything that ails you:

"The leaves and flowering tops are anthelmintic, anti-inflammatory, antiseptic, aromatic, astringent, carminative, diaphoretic, mildly diuretic, febrifuge and stimulant"

If you try to go beyond folklore and look for solid evidence that goldenrod works on a particular ailment, there's very little there. For instance, one study which looked at the potential antibacterial activities of several herbs including a common goldenrod species did not cite it as effective, even in a test tube setting (lots of compounds work in test tubes, even if they fail in the human body). They did cite another plant that produces neem oil as worthy of further study.

It's fun though to read about how goldenrod was used in olden times and to grow it in your garden (beware, some wild species are very invasive). The hybrid goldenrod Solidago 'Fireworks' is a beautiful plant.
Some people do have marked allergies to anything in the composite family, a cautionary note if you are planning to grow and/or use the plants medicinally.