From my chat with one of Thai friends:

- Can I ask you about small help? One of forum's members asks about poppers legality in Thailand. I can't find any official papers about it in English. May be you know official status of poppers in Thailand?
- Difficult to say, so far i know that it is not yet legal to sell in regular stores. But it seem ok to have. Also can find and buy it from some shop on the street around Silom or Nana for example. Also many from online shop.
- Thank you
- You're welcome, if your member like to bring it for personal use i think that's not a problem at all.