Is your thyroid medication actually working for you?

Do you take Synthroid or levothyroxine but continue to have symptoms of hypothyroidism?

One of the most common reasons that many people don’t feel great on T4 only medications (such as Synthroid or levothyroxine) is that their body is doing a poor job turning their medication (T4) in the active thyroid hormone T3. In order to feel energized, maintain your weight, and feel your best, you need high levels of T3 hormone which is the active thyroid hormone.

You can take medications which make your TSH and even T4 levels “normal” but if no one is testing your Free T3 levels you have no idea if your body is actually converting your medication into the active hormone.

Why do so many women struggle to convert their medication to T3? Well, there are several factors which can quickly derail conversion of T4 to T3.

Here are the most common factors that reduce conversion of T4 to T3:

  • Deficiencies of selenium, iodine, zinc, vitamin A, and vitamins B2, B6 & B12
  • Increased stress and high cortisol
  • High levels of cadmium, mercury, lead and fluoride
  • Starvation or very restrictive eating patterns
  • High carb/low protein diet OR very low carb diets
  • Chronic illness
  • Kidney or liver disease
  • Certain medications: beta blockers, birth control pills, estrogen

Wondering if you’re having a problem converting your medications properly? Find a practitioner who will test your Free T3 and Reverse T3 levels. Click here to read by article about my 5 Essential Thyroid Tests.

Want to learn more about my approach to thyroid health?

Book your FREE, no obligation, 15-minute Meet & Greet consultation with me.

Why testing your TSH alone isn’t telling you much about your thyroid

If you or your doctor suspect that you have a thyroid imbalance, the standard course of action is to run a TSH test. TSH stands for “thyroid stimulating hormone” and it’s made in the pituitary gland. Yes, that’s right, TSH is not made by the thyroid, it’s made by a gland in the brain. Now you might be wondering- why are we looking at a hormone made in the brain to assess the thyroid? That’s a great question!

TSH is an indirect way to look at your thyroid. I like to describe TSH as a doorbell. It’s a signal from the brain (ding-dong!) to the thyroid to make thyroid hormones (T4 and T3- which we’ll talk about in a minute). The assumption is that when your thyroid hormone levels drop, TSH will rise to stimulate the thyroid. The problem is that a TSH test on its own doesn’t tell us much. Is the thyroid responding properly to TSH and making T4 and T3?

T4 is the main hormone produced by the thyroid gland so it is a much more direct way to see how your actual thyroid is doing. If T4 levels are low, it means your thyroid is sluggish and isn’t making enough thyroid hormone. Keep in mind that T4 is a weak and mostly inactive hormone. Its main goal is to be converted into T3 which is the active thyroid hormone which gives you energy, helps you maintain a healthy weight, balances your mood and regulates body temperature. In my opinion, T3 is the MOST IMPORTANT thyroid hormone to test because it’s the one that is actually doing all the work and helping you feel good. TSH is just a signal. It has no direct impact on your weight, energy or mood.

Woman thyroid gland control isolated on white backgroundWoman thyroid gland control isolated on white backgroundLow T3 levels are incredible common and I can’t tell you how many women I see in my practice who have a low T3 hormone but their TSH is perfectly normal. So, if your doctor is only checking your TSH levels, they could tell you that everything looks great when in reality you may have low T4 and T3 hormone levels causing symptoms of hypothyroidism.Woman thyroid gland control isolated on white background

For a full picture of how your thyroid is working, I recommend getting a full thyroid panel that includes the following tests:

  • TSH
  • Free T4
  • Free T3
  • TPO (thyroid peroxidase) antibodies
  • TG (thyroglobulin) antibodies
  • Reverse T3

To learn more about each of these tests and the optimal ranges to look for, check out my 5 Essential Thyroid Tests for Women.

 To learn more about thyroid testing and treatment options,
book a complimentary 15-minute
Meet & Greet Consultation
with me at Docere Naturopathic Clinic + IV Lounge.

5 Essential Thyroid Tests for Women

If you are experiencing some of the following symptoms, it may be worth having your thyroid tested to rule out thyroid hormone imbalances:

  • Very slow or very fast heart rate
  • Weight gain or difficulty losing weight (or rapid weight loss)
  • Change in menstrual cycles (irregular periods, heavy periods)
  • Always feeling very cold or overly hot (or going from one extreme to the next)
  • Fatigue
  • Hair loss
  • Elevated LDL cholesterol level
  • Depression

5 Essential Thyroid Tests to ask for:

  1. TSH (thyroid stimulating hormone)
  2. Free T4
  3. Free T3
  4. TPO-antibodies & TG-antibodies
  5. Reverse T3

Understanding Your Test Results

1. TSH is short for thyroid-stimulating hormone, a hormone made by the pituitary gland (located in the brain) which tells the thyroid what to do. Think of it as the knock on the door. If the thyroid is not doing it’s job, the pituitary will knock more loudly (elevated TSH) whereas if the thyroid is working optimally, the knock will be very light (lower TSH). As you can see, TSH is not made in the thyroid meaning it’s an indirect way of looking at thyroid function.

High levels of TSH may indicate hypothyroidism (i.e. underactive thyroid), a pituitary gland tumor, or inadequate thyroid hormone medication in the treatment of a preexisting condition. Low levels of TSH may indicate hyperthyroidism (i.e. overactive thyroid), damage to the pituitary gland, too much thyroid medication in the treatment of a preexisting condition, or pregnancy in the first trimester.

  • Normal Range: 0.4-5 mIU/L
  • Optimal Range: 0.4 -2.5 mIU/L
  • Hypothyroidism = TSH > 5 mIU/L
  • Hyperthyroidism = TSH < 0.4 mIU/L

2. Free T4: T4 is the main hormone produced by the thyroid so it’s the most direct way at looking at actual thyroid gland function. Keep in mind that T4 is a very weak, mostly inactive hormone that’s main purpose is to be converted into T3 (see below).

  • Normal Range: 9-22 pm/L
  • Optimal Range: 14-18 pm/L
  • Hypothyroidism = < 9 pm/L
  • Hyperthyroidism =  > 20 pm/L

3. Free T3: is made from T4 throughout the body but mostly in the liver. T3 is the most active form of thyroid hormone and is responsible for giving us energy, revving up our metabolism, keeping us warm and with hair on our head. It’s vital to look at T3 hormone levels in order to gauge if there is thyroid dysfunction because you can have normal TSH and T4 levels but if you aren’t converting well to T3 you can still have symptoms of thyroid imbalance.

  • Normal Range: 3.4-5.9 mIU/L
  • Optimal Range: 4.5-5.5 mIU/L
  • Hypothyroidism =  <3.4
  • Hyperthyroidism =  > 6

4. Thyroid Antibodies (TPO and TG): Thyroid peroxidase (TPO), an enzyme found in the thyroid gland, plays a key role in the production of thyroid hormones. A TPO test detects antibodies against TPO in the blood, the presence of which suggests that the cause of thyroid disease is an autoimmune disorder (e.g. Hashimoto’s or Grave’s disease).

  • Normal Range: < 35 kIU/L
  • Auto-immune disease (e.g. Hashimoto’s or Graves’s) > 35 kIU/L

5. Reverse T3: is essentially a “dud” hormone that is made when the body is under stress. A small percentage of our T4 hormone is always converted to reverse T3 in order to prevent the body from being overstimulated by T3. However, in certain conditions, especially with higher stress and cortisol hormone levels, the body can convert too much T4 into reverse T3 which essentially blocks other thyroid hormones from doing their job.

  • Normal Range = < 9-24 ng/dL
  • Optimal Range = less than 18 ng/dL

These tests are all done through a simple blood test which your MD can request. Naturopathic Doctors are also able to run these tests which will cost approximately $100.