Improved
6112 HealthChanged
3785 LivesSaved
3568 Lives0 lives impacted in the last 24 hrs Learn More
Photo: Getty Images
Hypothyroidism occurs when the thyroid gland does not produce enough thyroid hormone. Thyroid hormone is a chemical messenger used by the brain to control many functions in the body including metabolism, which is how the cells use energy. The standard treatment for hypothyroidism is hormone replacement therapy.
About T3 and T4
The thyroid gland produces two main types of thyroid hormone which are known as T3 (triiodothyronine) and T4 (tetraiodothyronine). These two hormones control your body’s metabolism. Being low on thyroid hormone means your metabolism is slower than normal. This can affect how your heart beats, how you process food, how your body handles heat, and how well you can think.
The basic hormone produced by the thyroid gland is T4. When T4 enters your bloodstream and interacts with other chemicals it releases one iodine atom and becomes T3. T3 is generally the more active and stronger thyroid hormone. T3 carries messages from the brain to other cells to regulate the metabolism.
Hypothyroidism treatment provides extra thyroid hormone to the body. If your thyroid is still functioning but not keeping up, your hormone replacement dose may be lower than if your thyroid is not functioning at all. The U.S. Food and Drug Administration (FDA) regulates thyroid hormone replacements, which are only available by prescription.
Your doctor will prescribe the lowest dose possible to bring your hormone level into the normal range. Too much thyroid hormone replacement can cause other symptoms, including irregular heartbeat.
Synthetic thyroid replacement
Thyroid hormone replacement is available as a synthetic (lab-created) hormone which is most commonly called levothyroxine. This is considered by many to be the standard hypothyroidism treatment. Levothyroxine contains only the T4 hormone.
Proponents of synthetic replacement believe the body will convert T4 to T3 to complete the replacement process. Manufacturers claim that synthetic T4 is identical to the hormone produced by the human thyroid gland and claim it is superior to animal hormone replacements because the dose is more consistent.
The FDA has approved 6 brands of synthetic T4 replacement:
• Levo-T
• Levothyroxine Sodium
• Levoxl
• Novothryox
• Synthroid
• Unithroid
Although all these brands of T4 are considered to be identical to human thyroid, they do not all provide the exact same dose. If you begin treatment with one brand of this drug, do not change brands without consulting with your doctor so your dose can be monitored and adjusted if necessary.
Animal thyroid replacement
Animal thyroid replacement is created from the thyroid gland of certain animals. One common brand of animal replacement, Nature-Throid, contains both T3 and T4 hormone. The manufacturer claims this is preferable because natural hormone is more readily recognized by the body and may receive a more favorable response. They believe it is better to replace both T3 and T4 rather than just T4 in case the body is unable to convert T4 to the needed T3.
The manufacturer says Nature-Throid complies with all FDA standards. They say the drug is tested to maintain strict potency and consistency and has never been recalled for inconsistent levels.
Whether you are prescribed synthetic or animal hormone replacement, it is important to take the medication as directed. Do not take thyroid hormone replacement with food, or at the same time that you take certain medications including multivitamins, calcium, and antacids.
Hypothyroidism is diagnosed using blood tests to measure the amount of thyroid hormone or thyroid stimulating hormone in your system. Once thyroid hormone replacement therapy begins, your doctor will need to continue to check your thyroid levels to establish the best dose for your treatment and to make sure that dose continues to be effective.
Sources:
Medline Plus. Hypothyroidism. Web. December 21, 2011.
http://www.nlm.nih.gov/medlineplus/ency/article/000353.htm
Endocrine Web. What Is Thyroid Hormone Replacement Therapy?.. Eren Berber, MD. Web. December 21, 2011.
http://www.endocrineweb.com/conditions/hypothyroidism/what-thyroid-hormone-replacement-therapy
Endocrine Web. Synthetic T4 Supplements for Hypothyroidism. Eren Berber, MD. Web. December 21, 2011.
http://www.endocrineweb.com/conditions/hypothyroidism/synthetic-t4-supplements-hypothyroidism
Endocrine Web. Animal Thyroid Supplements for Hypothyroidism. Eren Berber, MD. Web. December 21, 2011.
http://www.endocrineweb.com/conditions/hypothyroidism/animal-thyroid-supplements-hypothyroidism
Medicine Net. Hypothyroidism. Ruchi Mathur, MD, FRCP(C). Web. December 21, 2011.
http://www.medicinenet.com/hypothyroidism/page5.htm#toc7at
Nature-Throid. Nature-Throid ™ vs. Synthetic Thyroid. Web. December 21, 2011,
http://nature-throid.com/nature_throid_vs_synthetic_thyroid.html
Reviewed December 22, 2011
by Michele Blacksberg RN
Edited by Jody Smith
Add a Comment2 Comments
I was first prescribed Synthroid and my hypothyroid symptoms of weight gain, fatigue, constipation and depression did not go away. Thankfully I found a doctor who prescribed Nature-thyroid, which includes T3 in it, and my life changed. I was diagnosed with hypothyroidism following the birth of my first son in 2006 and experienced many of the symptoms you have listed. I trusted my doctors completely assuming they knew everything there was to know about this disease, especially when I became pregnant again in late 2008. How wrong I was! Under their care my TSH, the gold standard for measuring thyroid function, rose high above the safe range for pregnancy and I miscarried. I vowed to myself that I would research everything there was to know about hypothyroidism and warn other women. I fulfilled my vow and launched my blog Hypothyroidmom.com in memory of the baby I lost to hypothyroidism.
October 21, 2012 - 5:54amThis Comment
Thank you Denise for such an open minded article on hormone replacement! It is nice to see words written that emphasize what the manufactures say, and not just opinion of the writer.
As someone with Hashimoto's, switching types of medication not only made a big difference for me, but also brought about the best surprise any woman could imagine. My first son :)
As a hypothyroid sufferer, and advocate for thyroid patients, it is important to get all the facts out there so that thyroid patients can determine which medication is best for them based on how they feel. Since no two people are alike, it is great to let them know there are medication options out there. It may take some time to find which one works best FOR YOU, at which dose, but in the end it is worth it to finally find your own euthroid state.
For some, synthetic medications work best. For others, trying different medications may make a world of difference.
For anyone who is having a problem trying the different medications due to refusal of the doctor, here is a link to help get you started. http://thyroid.about.com/cs/thyroiddrugs/l/blletter.htm
Unfortunately in this country some in the medical community are not always eager to try "new" approaches, so communicating with your doctor what your wishes are and trying to work with them instead of against them can make a big difference.
The biggest point here is to try different approaches until you find the one that works for you!
Thanks again!
Auntlello1
December 23, 2011 - 12:34pmThis Comment