The dried flower buds may contain as much as 20% rutin with some quercetin.

S. japonicum dried fruit contains the flavonoid glycosides sophoricoside, genistin and rutin and the flavonoid aglycones genistein, quercetin and kaempferol.

Another analysis found genistein and genistein glycosides including sophorabioside, sophoricoside, genistein-7-diglucoside, genistein-7-diglucorhamnoside, and kaempferol and the kaempferol glycosides kaempferol-3-sophoroside and kaempferol-3-rhamnodiglucoside.

The fruit also contain the alkaloids cytisine, N-methylcytisine, sophocarpine, matrine and stizolamine.