As with other marine products, concern has been expressed that toxic heavy metals may be found in certain lots. I don’t know how meaningful this concern is regarding the frequency of this occurrence. Maybe just take a slightly higher dose of non-marine sourced product to make up for the poorer absorption?
Thanks, Steve. After reading your comment, I found a paper with test results of heavy metal content of many collagen supplements. Unfortunately, it was back in 2020, so not fully up to date.
On page 10, they list the products they tested and the amounts of heavy metals that were found.
I haven’t read the whole paper and don’t know how much of a concern these amounts of heavy metals are.
On page 7, they list the 3 products with the lowest levels of heavy metals.
https://cleanlabelproject.org/collagen-white-paper/