Hormones Metabolism Weight Gain Thyroid BHRT

Is Hormone Decline Slowing Your Metabolism?

Hormone decline affects metabolism, energy, and weight. Learn how estrogen, testosterone, and thyroid impact your metabolic health from Soluna Vitality.

Dr. Andrea Ridgeway
5 min read
Scale and measuring tape representing metabolic health

If you’ve noticed that weight loss has become harder, your energy has tanked, or your body just doesn’t respond to diet and exercise the way it used to—you’re not imagining things.

For many adults, especially those over 40, these changes aren’t simply a matter of willpower or aging. They’re often signs of hormone decline.

In this post, we’ll explore how hormones regulate metabolism, what happens when they decline, and what you can do to restore balance and reclaim your vitality.

What Is Metabolism, Really?

Metabolism refers to all the chemical processes your body uses to convert food into energy. It determines:

  • How many calories you burn at rest (basal metabolic rate)
  • How efficiently you use carbohydrates, fats, and proteins
  • How well you maintain muscle mass
  • How you store or release fat
  • Your energy levels throughout the day

Metabolism isn’t fixed—it’s dynamic and heavily influenced by hormones.

The Hormones That Control Metabolism

Thyroid Hormones (T3 and T4)

The thyroid is the master regulator of metabolism. It controls how fast your cells produce energy. When thyroid function is low (hypothyroidism), metabolism slows dramatically, leading to:

  • Weight gain or difficulty losing weight
  • Fatigue and sluggishness
  • Cold intolerance
  • Constipation
  • Brain fog

Even subclinical hypothyroidism—where TSH is elevated but T4 is still in range—can impair metabolism and cause symptoms.

Estrogen

Estrogen plays a key role in regulating body fat distribution, insulin sensitivity, and appetite. As estrogen declines during perimenopause and menopause, many women experience:

  • Increased abdominal (visceral) fat
  • Reduced insulin sensitivity
  • Changes in hunger and satiety signals
  • Slower metabolic rate

Research shows that estrogen deficiency is associated with increased fat mass and decreased lean mass, independent of aging (Lizcano & Guzmán, Gynecol Endocrinol, 2014).

Progesterone

Progesterone has a calming, anti-inflammatory effect and supports sleep—both of which influence metabolism. Low progesterone can lead to:

  • Anxiety and poor sleep
  • Water retention
  • Increased cortisol and stress-related weight gain

Testosterone

Testosterone supports muscle mass, fat metabolism, and energy in both men and women. Low testosterone is linked to:

  • Loss of lean muscle
  • Increased body fat, especially around the midsection
  • Fatigue and low motivation
  • Reduced exercise capacity

In men, testosterone decline (andropause) begins around age 30 and accelerates after 50. In women, testosterone drops significantly after menopause.

Insulin

Insulin is the hormone responsible for shuttling glucose into cells. When cells become resistant to insulin—a condition called insulin resistance—blood sugar rises, fat storage increases, and metabolism becomes impaired.

Insulin resistance is closely linked to:

  • Abdominal obesity
  • Type 2 diabetes
  • PCOS (in women)
  • Cardiovascular disease

Cortisol

Cortisol, the stress hormone, influences blood sugar, fat storage, and appetite. Chronic stress leads to elevated cortisol, which:

  • Promotes fat storage, especially visceral fat
  • Increases cravings for sugar and carbs
  • Breaks down muscle tissue
  • Disrupts sleep and recovery

When hormones decline, metabolism doesn’t just slow—it changes how your body stores and uses energy.

  • Unexplained weight gain, especially around the midsection
  • Difficulty losing weight despite diet and exercise
  • Fatigue or low energy, especially in the afternoon
  • Loss of muscle mass or strength
  • Increased hunger or cravings
  • Poor sleep or waking unrefreshed
  • Brain fog or difficulty concentrating
  • Mood swings, irritability, or anxiety

If these symptoms sound familiar, your hormones may be part of the puzzle.

What You Can Do About It

1. Get Comprehensive Testing

Standard labs often miss the full picture. At Soluna Vitality, we assess:

  • Thyroid panel: TSH, Free T3, Free T4, Reverse T3, TPO antibodies
  • Sex hormones: Estradiol, progesterone, total and free testosterone, SHBG
  • Metabolic markers: Fasting insulin, HbA1c, lipid panel
  • Adrenal function: Morning cortisol, DHEA-S

Testing helps identify which hormones are out of balance and guides personalized treatment.

2. Optimize Nutrition

  • Prioritize protein to support muscle and satiety
  • Include healthy fats for hormone synthesis
  • Choose low-glycemic carbohydrates to stabilize blood sugar
  • Avoid processed foods, excess sugar, and alcohol

3. Prioritize Sleep

Sleep is when your body repairs, detoxifies, and resets hormones. Poor sleep raises cortisol, disrupts insulin, and impairs thyroid function. Aim for 7–9 hours of quality sleep per night.

4. Manage Stress

Chronic stress keeps cortisol elevated, which sabotages metabolism. Incorporate stress-reducing practices like:

  • Breathwork and meditation
  • Time in nature
  • Gentle movement (yoga, walking)
  • Social connection

5. Exercise Strategically

  • Resistance training preserves muscle and boosts metabolic rate
  • Cardio supports cardiovascular health and insulin sensitivity
  • Avoid overtraining, which can raise cortisol and worsen fatigue

6. Consider Hormone Replacement Therapy

For many patients with confirmed deficiencies, bioidentical hormone replacement therapy (BHRT) can help restore metabolic function, energy, and body composition.

At Soluna Vitality, we offer personalized BHRT using hormones that are molecularly identical to those your body produces. Treatment is tailored to your labs, symptoms, and goals.

The Bottom Line

Hormone decline is a normal part of aging—but suffering through the symptoms doesn’t have to be. If your metabolism feels stuck, your energy is low, and your body isn’t responding the way it used to, it may be time to look deeper.

At Soluna Vitality, we specialize in comprehensive hormone and metabolic health. We’ll help you identify root causes, restore balance, and build a plan that supports your long-term vitality.

Schedule a consultation to start your journey toward a healthier, more energized you.

References

  1. Lizcano F, Guzmán G. Gynecol Endocrinol. 2014;30(1):1–6.
  2. Mullur R, Liu YY, Brent GA. Physiol Rev. 2014;94(2):355–382.
  3. Kelly DM, Jones TH. J Endocrinol. 2013;217(3):R25–R45.
  4. Pasquali R et al. Obes Rev. 2006;7(1):21–32.
  5. Boden G et al. J Clin Invest. 1996;97(4):1020–1025.