A selective, brain penetrant, full agonist for the 5-HT1F receptor (pKi = 8.2). It possesses little affinity for the 56 other serotonergic and non-serotonergic neuronal binding sites examined. When examined for its ability to inhibit forskolin-induced cyclic AMP accumulation in cells stably transfected with human 5-HT1F receptors, LY344864 was shown to be a full agonist producing an effect similar in magnitude to serotonin itself. Suitable for both in vitro and in vivo applications and its effects are often reversed with the 5-HT1B/1D antagonist GR 127935.