New blood tests that can gauge the length of telomeres in the human body are now going on sale, marketed by some laboratories as revealing the subject’s biological age.

Experts disagree on the relevance of telomere length as an indicator of biological age.

Some of the labs offering the test call it more of a warning flag than an indicator of the biological age. Certain telomere experts, such as Dr. Carol Greider, who shared the Nobel Prize in 2009 for discoveries related to telomeres, acknowledged there is solid evidence that the 1% of the population with the shortest telomeres have an increased risk of certain diseases, but outside of that, “The science really isn’t there to tell us what the consequences are of your telomere length.”

In a statement Wednesday, the FDA said they were aware of the tests, but had not yet come to any conclusions as to whether they would require official approval.