It often begins with a small change. Your usual workout feels harder. You need longer to recover. You feel less strong than you did a year ago. Or you notice a change around your waist that doesn’t seem to match your routine.
It’s tempting to give those changes one name—“aging”—and search for one solution. But your body is more complicated than a headline. A conversation about energy may begin with sleep, food, medications, or a health condition. A conversation about strength may begin with how you train and eat. A change in your waistline deserves context, too; a tape measure or a quiz cannot tell you how much visceral fat you have or why your body composition has changed.
The first useful step is to get specific about the change you want to understand.
Four places to begin
Energy and stamina. When did your energy change? Is it constant or does it vary? How are you sleeping and eating? Persistent fatigue has many possible causes, including sleep disorders, anemia, thyroid disease, other conditions, and medication effects. A thoughtful history and appropriate evaluation matter more than assuming every tired day reflects a problem with cellular energy.
Recovery and resilience. If activity leaves you feeling unusually depleted, look at the whole routine. How much effort are you asking of your body, and what time are you giving it to recover? Sleep, nutrition, training load, and symptoms that linger are all worth discussing.
Strength and muscle. Maintaining strength becomes a meaningful goal as we get older. Resistance exercise can help preserve muscle and function, and the right plan depends on your health, starting point, and abilities. If strength or exercise capacity is changing, the goal is to understand that change and build a realistic plan.
Waist and metabolic health. An increasing waist can raise questions about body composition and health, but “stubborn belly fat” is not a diagnosis. Looking at history, habits, and appropriate measures gives you a better foundation for discussing options.
Take our two-minute Healthy Aging Priorities Quiz to find the question you most want to bring to your next health conversation. The result reflects your priorities; it does not assign a treatment.
Where do mitochondria fit?
Mitochondria help cells make the energy they need to function. Researchers study how mitochondrial quality and activity can change with age. That is an important part of aging science, but it does not mean every instance of fatigue can be traced to mitochondria—or that a single supplement or peptide will fix it.
This is one reason the peptide discussion needs careful language. Compounds often appear together in “longevity” posts even though their mechanisms, human evidence, safety information, and approved uses are quite different.
Four names you may be hearing
MOTS-c is a mitochondrial-derived peptide being investigated for metabolic signaling. Research interest should not be confused with proof that it improves everyday energy or healthy aging in people. The FDA has identified important gaps in human safety information for compounded MOTS-c.
SS-31 (elamipretide) has been studied in relation to mitochondrial function. In 2025, the FDA granted accelerated approval to elamipretide for improving muscle strength in certain patients with Barth syndrome, a rare genetic condition. That specific approval does not establish a general anti-aging or fatigue benefit.
CJC-1295 and ipamorelin are discussed in connection with growth-hormone signaling. They are often marketed for sleep, muscle, and recovery, but marketing claims should be weighed against limited clinical evidence and the FDA’s stated concerns about certain compounded preparations.
Tesamorelin is approved to reduce excess abdominal fat in adults with HIV-associated lipodystrophy. That is a defined medical indication. A changing waistline in someone without that condition does not itself suggest tesamorelin is appropriate.
Come with better questions
When you hear a promising claim, ask: What was studied in humans? Who was studied? What outcome improved? Is this use FDA approved? What safety questions remain? And how would a clinician evaluate my own symptoms before discussing treatment?
I’ll explore those questions in Peptides 301: Mitochondria, Aging, and What the Peptide Conversation Gets Right—and Wrong on Thursday, October 15, 2026 at 4:00 p.m. MT. This free online session will cover the science, the uncertainty, and the practical questions worth asking.