If you are desperate for poppers in Thailand get it throught Internet from Holland at
http://poppers-shop.com
From ordering to reception it took 5 days!
If you order enough bottles at a time it can cost as little as 250 BHT per bottle (it used to be 700 BHT in Patpong 2).
If you get the most popular brand (Rush)
which has a little white pellet inside and if you keep it in the freezer it will never go stale or smell, irritate your nostrils and will remain powerful until the last drop. You also can keep new bottles for years in the freezer before they go bad.
I ordered twice from that site with complete reliability and was charged the exact amount. The product is genuine and the bottles are full and not leaking.
I saw some Thai guys in the saunas taking some very long, deep and frequent breathings from their stale popper bottle trying to get a kick. Then that scary!