Complex sentence: It has been researched for medicinal use but showed little advantage over other analgesics, although it did seem promising for treating opiate withdrawal it was not as good as buprenorphine for this purpose.
Split into simpler sentences: It has been researched for medicinal use but showed little advantage over other analgesics. Although it did seem promising for treating opiate withdrawal, it was not as good as buprenorphine for this purpose.