It is difficult to say a dosage - especially when you start with “9”. I read that 10 should be an upper limit per day. I have also seen an article mentioning 20mg per day … however I am skeptical about that dose.
There is only ONE supplement that I am aware of that has 6mg per two capsules. The rest usually have 3 mg elemental boron per two capsules. That means, to start with 9mg, you are taking six capsules per day. Not bad as long as you are not taking a handful of other supplements with it.
I have talked about the 6mg BIO IMMERSIONS supplement before, yet I am still not taking it because of how many bottles of my previous brand that I bought. Amazon no longer has it - manufactuer is Bio Immersion.
[My live link to the manufacturer was deleted by mods. It is easy to find by searching].
BIO IMMERSIONS uses a patented blend of calcium fructoborate which I have written about before as the best, with studies to support that statement.
There is ONE 6mg boron liquid that I am aware of. Apparently it has a “strong metal taste” and must be mixed with some other liquid. I have never tried it as it seems more trouble than it is worth - and is not a calcium fructoborate product. Research boron - the “type” of boron you take does make a difference.
I write on this board often about boron and SHBG; only because I have tested the results with blood work.