Active ingredients include alkaloids and other potent antioxidant compounds, such as saponins, quercetin, and kaempferol.
 
There are many benefits of using hydrangea root that include its ability to limit bladder infections, reduce inflammation, and prevent autoimmune diseases, among others.
May reduce the size of an enlarged prostate
May prevents bladder infections by acting as a diuretic
May limits the appearance of urethral infections
May dissolve kidney and gallbladder stones [3]
May help fight back against parasitic infections
Might lower inflammation throughout the body
May reduce the risk of chronic diseases due to its antioxidant properties
May soothe the pain of rheumatoid arthritis and gout
Might relieve pain in inflamed or irritated tissues
May strengthen the immune system and prevents autoimmune diseases [4]
May prevent cystitis in women
May reduce risk of hay fever
Might help treat calcifications
Can act as an antiseptic and antilithic
Can help treat malaria
https://www.organicfacts.net/hydrangea-root.html