A normal TSH may not be enough to reduce your hypothyroid symptoms

The standard approach to diagnose and treat hypothyroidism is to measure your TSH and T4 levels with blood tests.  Then, depending on the levels of these two markers, your doctor will prescribe T4-only medication (which contains levothyroxine, a synthetic T4 medication under the brand names like Eltroxin or Euthyrox), or adjust your prescription.  The goal?  To get your TSH and T4 to be within the lab’s “normal” levels.

Does this approach work? 

For some, yes.  For many, no.  It didn’t work for me, and despite being within “normal” levels for many years, I still experienced hypothyroid symptoms such as fatigue, exhaustion, forgetfulness, picking up more and more weight, to name a few. 

But has there been any research done to find out if this “gold standard” approach is the best treatment methodology?  

Yes.  I want to share some eye-opening insights from a study that might change the way we think about levothyroxine treatment. 

Published in the Journal of Clinical Endocrinology & Metabolism (Oct 4, 2016), this study analyzed data from nearly 10,000 individuals who were part of the US National Health and Nutrition Examination Survey (NHANES) between 2001 and 2012.

What makes NHANES so valuable is that it’s a population-based survey that pulls from a representative sample of the entire U.S. population. This isn’t just a clinical trial where participants are already focused on a specific health issue. Instead, it captures a broad snapshot of the nation’s health and nutrition.

Here’s what the study found: among the 9,981 participants with normal TSH levels, 469 were on levothyroxine treatment. When compared to a matched group of healthy individuals, those on levothyroxine had lower free and total T3 levels by 5–10% and higher free and total T4 levels by 10–15%. Their T3 ratios were also 15–20% lower.

But here’s the kicker—despite having “normal” TSH levels, those on levothyroxine were about 10 pounds (about 4.5 kg)  heavier, even though they consumed fewer calories and had significantly lower physical activity levels. They were also 30-40% more likely to be on antidepressants, statins, or beta-blockers.

The takeaway? 

A normal TSH level might not mean your thyroid hormone levels are truly balanced across all tissues and organs. If you’re on levothyroxine and not feeling your best, this could be why.