Original sentence: Although not related to organic opioids, tramadol can produce a very pleasant high in many users.The high brought on by tramadol may not be just from its opioid activity, but also from its sudden action on serotonin and norepinephrine, which may explain the stimulant-like effects.Tramadol is marketed as a racemic mixture with an affinity for the μ-opioid receptor
Edited sentence: Although not related to traditional opioids, tramadol can produce a very pleasant high in many users.The high brought on by tramadol may not be just from its weak opioid activity, but also from its sudden action on serotonin and norepinephrine, which may explain the stimulant-like effects.Tramadol is marketed as a racemic mixture with a weak affinity for the μ-opioid receptor (approximately 1/6000th that of morphine; Gutstein & Akil, 2006)