I like immune support options that are more natural, but am always skeptical of stated results until I've tried it myself. So when this was recommended to me, I didn't really expect to notice the effects.
Now, I have one at home and one at work because the moment I start to feel a cold sore coming on, feel like I'm heading for a cold, or feel my stress levels rising, I go straight for this because it definitely works for my system.
My cold sores/fever blisters used to be a major problem, but as long as I can get to this right when I feel them starting, it's 90% of the time that they will disappear within a few hours.
I work with kids, so whenever the stomach/respiratory/etc bugs are going around campus, I use this in the morning to proactively boost my immune system. Comparing previous years, and how I'd always end up with laryngitis, bronchitis, or the stomach bug at least 2-3 times a year- with the last few years I've been using this, I've only taken one sick day off in a 3 year time period.
For me, this has been a great support and it lasts a long time too, so well worth the money. For my friends who wonder if it's a placebo effect, I'd say it's still an affordable mental placebo boost :)