First, if you're on any drug such as benzos or neurontin that target GABA don't take this. Second, GABA supplements don't usually cross the blood/brain barrier, so they don't usually work. The best way to supplement for GABA, assuming you're not on medication that targets it, is to take the pseudo amino acid taurine and B6, which together with other co-factors make GABA in the body. There are also many many relaxant herbs that target GABA at least in part -- a small list is kava, valerian, hops, and passionflower, but there are many more. Passionflower is more systemic in action, while kava is the most like benzos but watch out for the standardized version if you have any liver problems. I did try GABA supplements once and it made me more nervous, but everything has been weird for me since Paxil withdrawal. I don't think it would do you any harm other than possibly wasting your money to try it. By the way, when you tackle anxiety with natural means, you generally go after the whole body -- you wouldn't just go after GABA, you'd also go after serotonin and the adrenals and even the kidneys in Chinese medicine, do meditation, exercise, do therapy, change your diet, etc. -- the holistic approach.
I tried Gaba, or should I say my naturopath had me try it. For me, it was a big mistake, it added to my anxiety attacks and brought them on. I guess everyone is different however. I am sadly one of those that anti-anxiety herbs or supplements work opposite on and drugs.....well forget it, I ended up in the ER when I took Paxil.