I don't know the answer. Many people on the FB groups stop taking collagen (and other related) supplements because of the implied risk. Collagen powders are used in medicine usually applied on wounds or injected into joints, and I personally find it hard to understand how they can affect skin collagen if taken orally. But, I found a recent research paper that suggests oral collagen can indeed have an effect on some aspects of biology of the skin. I don't really understand all the terms in this paper and there is no suggestion of a link to Dupuytren's so make of it what you will. https://pubmed.ncbi.nlm.nih.gov/37074675/
Thanks I'll read through the article but on surface it seems to indicate that it would maybe be an issue for DD...I was taking a good amount over a year period. It really improved the quality of my skin in many ways. But if it is harmful for the DD, I will stop using it.