Comparing Synthroid vs. Armour Thyroid vs. Generic Levothyroxine

About 2% of U.S. adults have symptomatic hypothyroidism, a condition in which the thyroid gland doesn’t produce enough thyroid hormones. 

Hypothyroidism is treated by taking medication to replace the missing hormones. The FDA estimates that over 22 million people take levothyroxine, a synthetic thyroid hormone that is the active ingredient in brands like Synthroid, Unithroid, Levoxyl, and Euthyrox. In addition, more than 1.5 million people take natural thyroid hormones derived from animals.

Understanding hypothyroidism and your treatment options can help you work with your doctor to find the right treatment for you.

What Is Hypothyroidism?

Your thyroid gland produces hormones that regulate metabolism: triiodothyronine (T3) and thyroxine (T4). The thyroid produces them based on signals from the brain and pituitary gland, and these hormones help your body utilize energy. When it doesn’t make enough, the condition is called hypothyroidism, or underactive thyroid.

Without enough of these hormones, you may have symptoms like:

• Fatigue
• Unexplained weight gain
• Heightened sensitivity to cold
• Dry skin
• Facial swelling
• Hoarse voice
• Constipation
• Changes to hair texture
• Body aches
• Heavy or irregular menstrual cycles

Not everyone with hypothyroidism has symptoms, though typically the lower the thyroid hormone levels, the more severe the symptoms. 

Hypothyroidism can be diagnosed with a blood test, and it can be treated with medication that mimics the missing hormone(s), also called thyroid replacement therapy. Thyroid medications commonly improve symptoms within weeks. Doctors monitor your thyroid levels with blood tests to ensure you are taking the right dose.

Common Thyroid Treatments

Synthetic Thyroid Medications: Is Synthroid the Same As Levothyroxine?

Synthroid is the same as levothyroxine. Levothyroxine is the generic name for the active ingredient, and Synthroid is a specific brand name formulation. Levothyroxine (Synthroid) is a synthetic, lab-made version of the T4 thyroid hormone. If your body doesn’t make enough T4 naturally, taking levothyroxine helps make up for the shortfall. This raises your thyroid hormone levels and treats the symptoms of hypothyroidism. 

Other Brand Name Options

Levothyroxine is available in a under different brand names, including Unithroid, Levoxyl, and Euthyrox. 

All of these medications have the same active ingredient and are used to treat hypothyroidism. However, there are some differences in the inactive ingredients used to make the tablet or pill per brand. 

In rare cases, those inactive ingredients change how your body processes the medication. As a result, your response to levothyroxine may differ between the generic and brand formulations or from brand to brand. For this reason, providers usually suggest trying to stick with the same version once you know it’s working. 

However, if you have to switch, your condition can still be treated just as effectively, though your doctor may need to make dosage adjustments based on how your body reacts to the medication.

T3 Vs. T4 Synthetics: Liothyronine vs. Levothyroxine

The thyroid gland makes much more of the hormone T4 (thyroxine) than T3 (triiodothyronine) because T3 breaks down more quickly. Also, T4 is more versatile because when needed, the body can convert T4 into T3.  

Levothyroxine is a synthetic version of T4, and liothyronine is a synthetic version of T3. Levothyroxine alone is typically effective in treating hypothyroidism, especially because your body can continue converting T4 into T3 even if you have impaired thyroid function.

In addition, because T3 is short-acting, it is harder to manage levels with medication. Levels can fluctuate significantly even when taking multiple doses per day, and it’s common to have symptoms from excess T3 right after taking liothyronine. 

While most do not need to take both liothyronine and levothyroxine to treat hypothyroidism, doctors may consider combination therapy depending on the cause of hypothyroidism and your response to levothyroxine alone.

Natural Desiccated Thyroid (NDT): Armour Thyroid vs. NP Thyroid

Natural desiccated thyroid (NDT) medications provide T3 and T4 hormones derived from the dried thyroid glands of animals, unlike synthetic hormones produced in laboratories. But like synthetic options, natural thyroid medications are designed to make up for the body’s inability to produce sufficient thyroid hormones on its own. 

Two of the most well-known NDT options are Armour Thyroid and NP Thyroid. These tablets contain the same ratio of T3 to T4 derived from pig thyroid glands. However, they have different inactive ingredients that may impact which one a patient prefers.

Until the 1970s, NDT was the most common treatment for hypothyroidism. Over time, synthetic hormones became more frequently prescribed because their lab-made quality means more consistency in formulation.

Synthetic vs. Natural Thyroid Medications

Beyond how they are produced, a key difference between synthetic and natural thyroid medications is the hormones they contain. The most common synthetic medication is levothyroxine, which replicates the T4 thyroid hormone. Natural desiccated thyroid medications include both the T4 and T3 hormones. Doctors generally recommend synthetic hormones because consistency in formulation is easier to maintain in a controlled laboratory. 

Both hormones are not necessary to treat most cases of hypothyroidism because the body can convert T4 into T3 when necessary. In fact, too much T3 can pose problems for patients with abnormal heart rhythms. That said, combination therapy with T3 and T4 may be more effective for some individuals.

However, that doesn’t mean that there’s no place for natural thyroid hormones. Things like genetics and nutritional deficiencies can change how thyroid hormones are processed in the body, and some studies have found that some patients feel better taking natural hormones over synthetic medications. 

Which Thyroid Medication Is Right For You?

The right thyroid medication depends on your symptoms, hormone levels, the cause of hypothyroidism, and your overall health. For many doctors and patients, the simplest treatment is synthetic levothyroxine, a T4 hormone available in generic and brand-name tablets. Taking levothyroxine daily is often effective at resolving the symptoms of hypothyroidism. 

However, no single treatment works for everyone. You may have persistent symptoms even after taking synthetic levothyroxine, or you may prefer to use a natural desiccated thyroid medication.

Talk with your doctor about the pros and cons of the different options in your case. No matter which medication you choose to take, an online pharmacy platform can be a convenient way to get your medication delivered to your doorstep. However, make sure to source it from a reputable pharmacy as online pharmacy scams can involve impure or inferior formulations, putting your health at risk.

TelyRx only works with trusted U.S.-based distributors and wholesalers to maintain quality control. We are also LegitScript-certified, HIPAA compliant, and work with U.S.-licensed pharmacies and licensed physicians to bring thyroid medicine to your doorstep.

Your Next Steps

Hypothyroidism is a lifelong condition, but for most people it can be effectively treated. Finding the right medication can make a big difference in how you feel every day. 

Your doctor can help you consider your options and find the right fit for your situation. If you’re thinking about taking a natural thyroid medication, bring that up at your appointment. Synthetic hormones are more commonly prescribed, but natural options can be a valid option worth discussing with your doctor.