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Thyroid and Muscle Loss

Thyroid imbalance and muscle loss in men


  • Many men suffering from low testosterone levels are also experiencing a thyroid disorder of some kind.
  • This could be hypothyroidism, a condition in which your thyroid produces critically low levels of thyroid hormones, or it could simply be because the production of thyroid hormones decreases as you age.
  • An underperforming thyroid can leave you feeling sluggish and unfocused.
  • You may find that you’ve lost the energy to exercise or that you’re losing muscle mass.
  • Muscle loss is a common symptom in men with low thyroid levels because the thyroid is responsible for transporting energy to various parts of the body on a cellular level.
  • A lack of these crucial hormones can lead to muscle weakness, muscle loss, and, in extreme cases, myopathy.
  • Bioidentical hormone replacement therapy replenishes both your thyroid and testosterone levels so you can finally feel like yourself again, regain your energy, and start building back lost muscle mass.

Wondering if you may have a low thyroid level? Take our free hormone assessment to see if you can benefit from Hormone Replacement Therapy. 

Why am I losing muscle mass?

It’s not unusual for muscle mass to decrease as men age, but why does this happen, and how is your thyroid responsible? The thyroid, located at the base of the neck, is largely responsible for energy and metabolism. It releases two crucial hormones, the active T3 (triiodothyronine) and the more inactive T4 (thyroxine), that help transport energy to cells throughout your body and skeletal muscles. Without enough of these hormones, you’ll have difficulty building new muscle through exercise and may lose existing muscle mass.

Studies show [1] that men who are middle-aged and older start to lose muscle strength due to the natural decline of hormone levels. Thyroid hormones, like testosterone, begin to fall as men age. While this is an expected part of aging, it can leave you feeling exhausted, unfocused, and not yourself. The absence of thyroid hormones can also result in hypothyroidism, a condition in which the thyroid produces critically low levels of T3 and T4.

Common symptoms of low thyroid levels in men include:

  • Muscle loss and weakness
  • Difficulty building muscle
  • Aching joints
  • Slow reflexes
  • Fatigue
  • Weight gain
  • Depression and mood swings
  • Lack of focus
  • Low libido
  • Dry skin
  • Brittle hair and nails

Thyroid dysfunction can be relatively hard to diagnose in men, especially since the symptoms of an underactive thyroid closely resemble the symptoms of low testosterone. Even if your thyroid levels aren’t critically low, they can easily fall below the desired level in aging men. A good rule of thumb is to pay attention to your body. If you’re experiencing these symptoms or struggling with muscle loss, you could probably benefit from bioidentical hormone replacement therapy (BHRT).

Start Bioidentical Hormone Replacement Therapy by completing a free hormone assessment and purchasing your at-home lab kit. 

Thyroid hormones and muscle loss

Although the thyroid regulates energy in many areas of your body, studies have found [2] that skeletal muscle is one of the primary targets of T3 signaling. Thyroid hormones control the oxidative metabolism of your cells, meaning their ability to gain and use energy for growth.

When the thyroid releases T3, hormone receptors in your muscles receive these signals, take in energy, and help your body build more muscle. As T3 production decreases, these receptors become unable to produce the same amount of energy, and muscle growth slows.

Another key link between your thyroid and your muscles is an enzyme called Type 2 iodothyronine deiodinase (DIO2) which helps convert the inactive T4 into active T3 that your body can use. Your thyroid produces much more T4 than T3, making conversion necessary for muscle growth and improved energy. The presence of DIO2 is increased in developing muscles [3] and helps them continue to grow, but DIO2 levels are typically low in men with myopathy or muscle loss. Thyroid treatment that exclusively provides T4 is often ineffective because, without these crucial converters, your muscles still aren’t getting a sufficient amount of active thyroid hormones.

Thyroid vs. Testosterone

Muscle loss is also a common symptom in men with low testosterone levels. The overlap between low testosterone and low thyroid occurs because the two depend on one another. Without enough thyroid hormones, testosterone production slows as well, depriving your body of energy and making muscle growth difficult. Through a hormonal chain reaction [4], thyroid hormones signal your body to produce more testosterone.

First, thyroid hormones stimulate the hypothalamus, which produces GnRH (gonadotropin-releasing hormones). These hormones then signal the pituitary gland which produces another key hormone, LH (luteinizing hormone). LH triggers the testes to start making testosterone and the cycle continues.

Your thyroid also produces important proteins called sex hormone-binding globulins (SHBGs), which bind to important sex hormones, like testosterone. SHBGs transport and regulate testosterone, ensuring optimal T levels throughout your body. Without them, you won’t see as many of the positive effects of testosterone production. This is why thyroid supplements are also crucial to seeing results in BHRT treatment.

Testosterone plays a huge role in your body’s muscle protein synthesis [5]; the process of building new muscle and maintaining muscle mass after exercise. Without the help of thyroid hormones, however, you have no way to retain your muscle strength or to use energy to build new muscle mass. You may be experiencing a lack of energy, but if you do feel up to working out, you likely won’t see the results you want without first replenishing your hormones. Not only is it difficult to build more muscle, but it’s also hard for your muscles to recover from the strain of exercise, leaving you vulnerable to muscle and joint pain.

How can BHRT help?

Thyroid dysfunction can occur for many reasons, from autoimmune conditions to simply aging, but if you’re struggling to build muscle or experiencing other energy-related symptoms, replenishing your supply of thyroid hormones can make a difference. You don’t have to wait until your thyroid levels are critically low to seek treatment, either. Many men experience thyroid deficiencies as they age and need to replenish these critical hormones to reach optimal levels and feel good again. With BHRT, you can achieve the optimal hormone levels you had in your youth and finally regain your vitality.

Benefits of thyroid treatment include but are not limited to:

  • Improved energy and sleep
  • Faster metabolism
  • Increased muscle mass
  • Weight loss
  • Better mood
  • More focus and motivation
  • Improved libido

With our at-home hormone test, you can assess your thyroid levels and ensure that you’re getting the optimal amount of thyroid hormones. When creating a treatment tailored to your needs, our US-licensed medical providers carefully consider your symptoms along with your blood test results. If your thyroid levels have you feeling sick, exhausted, and not yourself, BHRT can help give you the boost you need.

Feel energetic and strong with BHRT. It’s time to build back your muscle and feel like yourself again.

Ready to finally see the results you’ve been looking for? Get started with our free hormone assessment today to start on your HRT journey!

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