Thyroid Medication: Why It Doesn’t Always Work

“I am taking my thyroid medication every day, but I still feel tired all the time.”

I hear this statement far too often from my patients, and it is something that I have personally struggled with in the past.

The most common medication for hypothyroidism is synthroid (also called levothyroxine). Synthroid is a synthetic thyroid hormone designed to replenish low circulating thyroid hormone due to an under functioning thyroid gland.  In theory, this medication should work well, and it does for some people. However, there is also a large population who don’t feel any benefit from taking synthroid, myself included.

When I was first diagnosed with Hashimotos, I was put on synthroid for years with no major improvement in my hypothyroid symptoms. I was still exhausted, couldn’t focus, losing hair and feeling depressed. When I brought this up with my family doctor, she said that my lab results are normal so the synthroid must be working, and sent me on my way still feeling lousy.

Why Doesn’t Synthroid Work?

To answer that question, we must first learn a bit more about the thyroid gland. The majority of thyroid hormone that is produced by the thyroid is called thyroxin (T4). T4 is “inactive” and must become activated by cells within your body in order to be used to increase energy, increase metabolism, regulate our heart rate and blood pressure, balance mood and support cognitive function. Once activated, this super-power thyroid hormone is called triiodothyronine (T3).

Synthroid is a synthetic version of Thyroxin (T4), the inactive thyroid hormone. This medication works well if your body is activating it into triiodothyronine (T3). However, many people have difficulties converting T4 to T3, leaving your body with lots of fuel, but no ignition.

Adding to the puzzle, your lab results will most likely show up normal even though you don’t have enough activated thyroid hormone! This is because routine labwork for the thyroid gland includes Thyroid Stimulating Hormone (TSH) and maybe thyroxin (T4) levels, but triiodothyronine (T3) levels are rarely ever checked.

What Can I do About it?

If you are still experiencing hypothyroid symptoms while on synthroid, you are most likely not activating your thyroid hormone. The first step to recovery is to get your triiodothyronine (T3) levels checked to show if this is the problem. If T3 levels are low, there are alternative medications you can take that contain T3, such as desiccated thyroid or cytomel. There are also numerous nutrients and dietary changes that optimize your body’s ability to activate your thyroid hormone.

If you would like to get your thyroid back on track and finally feel more clear and energized, you can book an appointment with me at Local Health Integrative Clinic. I look forward to working with you on your journey to health and vitality!

Yours in Health,

Dr. Fiona