It might have seemed unlikely that something as deceptively straightforward as the cellular uptake of two arachidonic acid derivatives would cause so much controversy, but that is exactly the way things have turned out for the endocannabinoids anandamide and 2-arachidonoylglycerol since the first detailed description of their uptake [1]. The original debate concerned the existence (or not) of a designated membrane transporter protein, because a simple diffusion model followed by intracellular transport can explain current data as well as a model invoking an as-yet-unidentified membrane transporter [2].