That's a fascinating idea. I found one article in PubMed devoted to endometriosis and vit K, but it was above my head. The most I could make out from the abstract was that a protein involved in endometriosis is vitamin K-dependent. As for whether supplementing MK4 would help or aggravate your condition, I don't know. I also couldn't find any description of Carlson's vitamin K2 that said it had soy in it. So, I don't think soy from the supplement is involved.