Recently sampled this. Active at 10-29mg but I found around 50-60mg a more adequate dose for me. Quite mild in action and sort of leaves you wantng more, slightly lacking in euphoria compared to most other stimulants I thought but I didn’t have much material to work with and it could have been related to my ow mood when I tested it. Not the worst stimulant ever vut if you can get 3-FEA, chances are you can get 2-FA or 4-FA or something.