So I actually found something that reduces ferritin. IP6. It's a form of inositol. Made from rice bran. Chelates iron out of the body. Recommended for people with high iron, post-menopausal women, older men, etc. High iron is a risk factor for cancer.
Turmeric extract is also supposed to be helpful.
Drinking coffee or tea with meals helps reduce absorption of iron.
But IP6 is the best thing we've found so far.
DH has been on Jadenu off and on since my first post. That drug is really hard on the kidneys and some people go suddenly into kidney failure while on it.
Dh's labs have dipped into the "kidney disease" zone but go back to normal when he stopped the drug. His hematologist has him take jadenu as long as his kidneys seem to be doing ok, then stop when they're not. And then start again. And Jadenu is not even very effective. His ferritin is still much too high, even when he's taking it.
I'm hoping IP6 works better. It's certainly much safer than Jadenu.