Traditionally, Amsterdam Poppers were sold with an isopropyl formula, and many of their poppers still stick true to this. However, over the 30+ years since their inception, we’ve also seen Amsterdam release Amyl and Pentyl poppers.  There’s no ‘best’ formula and different people have their own preferences. If unsure, the best way to work out what you’ll prefer is to try! As a general rule, it is often said that amyl nitrite poppers will have a longer build up time to their peak and last longer. By contrast, it is often said that isopropyl and pentyl will take effect much faster, but equally last for a shorter amount of time.