S-methyl L-cysteine is a more absorbable form of selenium supplementation than L-selenomethionine, which can lead to toxicity if overused.

“the most absorbable form at least in terms of supplementation form is SE methyl elsa lino cysteine which i know life extension sells and some other people so you might have to go to a supplement first before you get everything back to normal and kind of hit it a little bit harder yeah Brazil nuts and there's lots of other things that have selenium in them that are really helpful to life but yes getting problems for me there are two types of selenium and supplements there's salento methionine and salento cysteine and Selina's cysteine is rare in supplements most supplements are salento methionine and they're poorly absorbed and you can definitely get toxic in selenium so do not over supplement with selenium”