It seems they've further tested whether 'wet cupping' / bloodletting by cupping therapy is capable of lowering iron levels.
"Al-hijamah (wet cupping therapy of prophetic medicine) significantly and safely reduces iron overload and oxidative stress in thalassemic children: a novel pilot study"
https://pubmed.ncbi.nlm.nih.gov/30588142/"Percutaneous excretion of iron and ferritin (through Al-hijamah) as a novel treatment for iron overload in beta-thalassemia major, hemochromatosis and sideroblastic anemia"
https://pubmed.ncbi.nlm.nih.gov/24857772/