Levels can rise when your body makes more of this inactive thyroid hormone or breaks down less of it. A 2026 review in Endocrine Journal explains how Reverse T3 (rT3) fits into thyroid hormone control. It brings together evidence from mice with altered genes and human gene differences. This was a review of existing knowledge, not a trial testing a new habit or treatment. The review describes three enzymes, proteins that help change thyroid hormones. They are called D1, D2, and D3. Each has a different job. D1 helps break down the inactive hormone. When D1 activity falls, blood levels rise. D3 helps make it from another thyroid hormone, called T4. Greater D3 activity can raise its levels while lowering T4 and T3. T3 is the active thyroid hormone. D2 mainly helps turn T4 into T3, supporting hormone action within the body's tissues. The key takeaway is that production and breakdown both matter. A higher result does not point to just one process. The supplied summary gives no percentage changes or target blood levels. It also does not show that lowering this marker through a particular routine improves health. For BioSocial members, this offers context for comparing bloodwork over time. A dated record of results, other thyroid tests, and routine changes can help frame community discussions. Comparing notes may reveal shared patterns, but cannot prove which enzyme caused a change. The review explains possible reasons for a result, rather than a way to judge a routine's success. What changes have you seen in your own results over time, and what else changed alongside them?