I hate to break it to you, but a lot of the GH sold in the countries you would want to go to (ease of acquiring)are fake. Seriously, I travel to Asia several times a year on business and I see fakes sitting in pharmacies.
The other downside is obviously your talking about bringing a controlled substance that our government considers as much of a crime as coke. That compounded with the fact that you are talking about GH...If you plan on running it the right way (+6 months) you are talking about bring back a minimum of 3 kits (30 vials). If you get caught it is the same penalties as getting caught with 30 vials of coke.....think about it. Now I did notice you said you would mail it back to yourself. Keep in mind if you are in Bangkok (or a laundry list of other countries) that shit will be seized by Customs coming back. Frankly, your run this risk shipping it back from any country outside the US
As already stated in this thread, by from a reputable domestic UG and you will get real GH and the best part is it will be shipped from someone in the US and will show up a couple days later.