Today I’d like to talk about Levothyroxine or Synthroid. This is likely the most commonly prescribed thyroid medication in the world but this is slowly changing. This article may be a bit difficult to follow so don’t feel bad if you have to read it several times before it all clicks. I usually spend about an hour educating patients about the thyroid with white board drawings too so 500 words may not be enough to get the full picture.
Thyroxine (T3) is the hormone that drives every metabolic process in our body, so of course, it’s extremely important. It turns all the factories in the body on, which then burns more fuel, which means thicker hair, less brain fog, not feeling cold all the time, and maintaining proper weight. We can get T3 two different ways. We can make it in the thyroid or we can convert T4 into T3. The thyroid is told when to make T3 and T4 by the brain. The brain secretes Thyroid Stimulating Hormone (TSH) which tells the thyroid to make T3 and T4. To make sure we don’t make too much T4 tells the brain to stop making TSH. This is where Levothyroxine can be a problem.
As we get older the body slowly loses its ability to convert T4 into T3. That means the only way we can get T3 is from the T3 produced by the thyroid and not T4 being converted into T3. This is often when we slowly begin to develop symptoms of hypothyroidism such as slow weight gain, brittle hair, fatigue, etc. Unfortunately, since there is enough T4, the TSH many times does not rise to a level where physicians will consider it a problem. Many patients tell us they’ve been tested for thyroid and it’s normal, when in fact they were not completely tested or the values were interpreted incorrectly.
If you do get diagnosed with hypothyroidism then most physicians will prescribe Levothyroxine or Synthroid which is a synthetic T4. You may already be able to see the problem here. If we are adding T4 to the system, two things will happen. First, the body will try to convert this T4 into T3. If our bodies cannot do this anymore then we will get little to no benefit from this medication. Secondly, T4 will tell the brain to produce less TSH which will reduce the amount of T4 AND T3 produced by the thyroid. In effect, ADDING LEVOTHYROXINE CAN LOWER YOUR T3 LEVEL! I see patients frequently who are on Levothyroxine who tell me they felt worse when their doctor raised their dosage. This is because each dosage increase can lower your T3 which is the ONLY hormone that drives your metabolism. To me it’s obvious. Hopefully it is to you as well now.
Thank you again for voting us Best in Destin for Women’s Wellness and Anti-Aging. I’m glad to have changed so many lives in our community. If this sounds like you or a friend of yours, please call us at (850) 837-1271. Dr Richard Chern, MD.