It usually takes me 45-60 min to start feeling LSD, but then the effects keep ramping up for a while before you eventually peak. Sometimes you THINK you hit your peak, but then later you find yourself way higher and realize you didn't really peak at all before and only THOUGHT you did! LOL After it starts kicking in though, your time perception will be all distorted, so you probably won't really know how long it takes (in normal people's time LOL) until you peak out. lol