Low T, Low Energy? What Every Man Should Know About Testosterone

Most men think testosterone only matters for sex drive. The hormone actually controls how your body builds muscle, where it stores fat, how much energy you have throughout the day, and even how sharp your mind feels.

When levels drop, the effects show up everywhere. At El Cajon Weight Clinic in El Cajon, California, James Joachim, MD, and our team help men figure out whether low testosterone is behind their struggles with weight, fatigue, and other frustrating changes.

Why testosterone levels drop

Testosterone production peaks in your late teens and early 20s, then starts declining. Some men maintain healthy levels well into their 60s. Others see a sharper drop that causes problems in their 30s or 40s.

Age isn’t the only factor. Several other issues accelerate the decline:

Obesity speeds up the drop because fat tissue converts testosterone into estrogen
Chronic stress keeps cortisol elevated, which suppresses testosterone production
Poor sleep interferes with natural hormone cycles since most testosterone gets produced during deep sleep
Certain medications lower testosterone as a side effect

Chronic conditions like diabetes or thyroid disorders can also throw hormone balance off.

How low testosterone changes your body

The effects of declining testosterone show up in multiple ways, often developing so gradually that men don’t connect the dots until several symptoms pile up. These include:

Muscle and fat distribution shift

Testosterone drives muscle protein synthesis, which is how your body builds and repairs muscle tissue. Without adequate levels, you can’t maintain the muscle you have, let alone build new muscle. The hormone also controls where your body stores fat. Lower levels shift storage toward your midsection, creating visceral fat that wraps around internal organs.

Energy and metabolism slow down

Low testosterone contributes to persistent fatigue that rest doesn’t fix. Mental fog often accompanies low T — trouble concentrating, memory problems, and reduced motivation all improve for many men when testosterone levels normalize.

Testosterone helps regulate metabolism and how efficiently your body burns calories. Lower levels slow this process, making weight gain easier and fat loss harder, even when eating habits haven’t changed much.

What testosterone replacement therapy (TRT) does

TRT supplies testosterone directly to bring your levels back into a healthy range. Some of the most popular delivery methods include:

Weekly or biweekly injections that provide consistent dosing
Daily gels that absorb through your skin
Patches that release testosterone steadily
Pellets implanted under the skin that last several months

Our team monitors your response through regular blood tests that check testosterone levels, red blood cell counts, and prostate health markers.

Some men feel more energetic within the first few weeks. You might sleep better or notice afternoon crashes disappear. The more visible changes can take a few months.

Diet and exercise amplify results

TRT creates better conditions for building muscle and losing fat, but healthy habits still matter. Strength training 2-4 times per week leverages improved muscle-building capacity. Adequate protein intake supports the muscle growth your hormones now enable.

At El Cajon Weight Clinic, TRT often pairs with other treatments for men facing significant weight challenges, like semaglutide or tirzepatide, which help control appetite. Supplements such as nicotinamide adenine dinucleotide (NAD) or sermorelin provide additional metabolic support.

Who should get tested

If you have persistent fatigue despite adequate sleep, weight gain concentrated around your belly, difficulty building or maintaining muscle, reduced sex drive, or mood changes, you may have low T.

Call our El Cajon office at 619-440-8171 or schedule online to learn whether testosterone replacement therapy fits your health goals.