I don't believe it.
The reason being, they don't tell you what is in it.
A proprietary blend might not tell you the amounts, but
they will tell you what it contains. For example, if you
have high blood pressure, you shouldn't take Licorice
(Glycyrrhizin), as it spikes BP to dangerous levels.
It's a great anti-viral, but needs to be monitored.
I personally think it's not on the level. Keep your
eyes open, though. You never know what may come around