This is a group of test results that I have found about Green Glue compound over the years, some of it published by the company itself, others from different sources, unrelated to the company, and that I have collected as reference material. Please note that I do not sell this product, and I do not accept advertising on the forum: this has nothing at all to do with advertising. However, there seem to be a lot of rumors and plain old wrong information on the Internet about Green Glue compound, what it is, and what it does, so I'm putting up this page with actual test data from independent testing facilities, so people can judge for themselves.
Basically, it's a good product, and it works well, but it is expensive. Very expensive. So it is not for everyone. On a tight budget, don't use it (unless you need very high isolation, and can find more money!)
On the other hand, using full coverage recommended by Green Glue (three tubes per 4'x8' / 120x240cm sheet of drywall) is about the same as adding THREE TIMES AS MANY layers of drywall to your wall (on each side).
How can I make such a ridiculous statement? Where do I get that from? Right here: That comes from the tests comparing Green Glue compound to MLV, and shows the clear superiority of Green Glue, but also note the comment in the test description: the improvement from using Green Glue is similar to the improvement you would get from "tripling the mass", which implies adding three times the number of layers of drywall to the existing wall, on each side. That alone is mighty impressive. (Also note that this testing was done down to 31 Hz, which is also impressive!)
My purpose here is not to promote the product, but rather to provide valid, correct test data about it, to correct some common misconceptions.
Drawbacks? Cost. It is expensive. It is also messy to apply, slows you down in your build as it takes a lot longer to apply it, and it only reaches peak performance after a month.
So, here's the data, in no specific order, except to start with a test done in Australia at the independent CSIRO ("Commonwealth Scientific and Industrial Research Organisation"), showing the rather impressive results that can typically be obtained: The rest of the data: