Remember, amino acids, besides LPA and tryptophan, cannot cross the blood-brain barrier - you have done this all on your own :-) be proud. The LPA does show promise for pain; it is eventually converted into catecholamines at the end of the metabolic chain. Catecholamines are what are partially responsible for the analgesic action of tramadol, beyond the mild u-opiate agonism, and is why SSRIs , tricyclics, and gabaergic drugs are sometimes used as adjuncts in the treatment of CP. It would likely be asking too much to rely on it as a main therapy instead of an adjunct. Good luck!