Does low testosterone actually cause low energy? The evidence is complicated

What did @dr.dickshard actually say?

The claim is straightforward: if you're crashing after work every day, low testosterone is "probably why," and TRT will restore "normal energy" so you can show up at work, the gym, and home. He's also drawing a clear line between TRT and bodybuilding, framing it as a medical fix rather than a performance boost. That's a more responsible framing than most TRT content on TikTok, but the core causal claim, that low testosterone is the likely driver of afternoon fatigue, is doing a lot of heavy lifting without much nuance to support it.

To his credit, he doesn't promise muscle gains or claim TRT will transform your physique. The focus is specifically on energy and daily functioning, which keeps this in medical territory rather than gym-bro territory. That's worth acknowledging before we pick it apart.

Does the science back this up?

Partially, but the relationship between testosterone and fatigue is messier than this video lets on. Fatigue is one of the recognized symptoms of hypogonadism, yes. But fatigue is also caused by sleep apnea, thyroid dysfunction, depression, iron deficiency, poor sleep hygiene, and about a dozen other things that have nothing to do with testosterone.

The evidence that TRT reliably improves energy in hypogonadal men is real but modest. A systematic review by Isidori et al. (2005, Clinical Endocrinology) found that testosterone treatment improved energy and reduced fatigue in men with confirmed low testosterone, but effect sizes were variable and not dramatic. The landmark TRAVERSE trial (Lincoff et al., 2023, New England Journal of Medicine), which enrolled over 5,000 men, showed TRT improved sexual function and bone density more consistently than it improved energy or mood. The energy benefits were real, but they weren't universal. Men with borderline-low testosterone, in particular, saw limited gains.

The afternoon energy crash specifically is not a documented testosterone symptom in the clinical literature. That framing is more pop-wellness than endocrinology.

What did they get wrong (or right)?

The biggest problem here is the word "probably." Saying afternoon fatigue is "probably" low testosterone, without any mention of alternative causes, is misleading. A responsible clinician would tell you that low testosterone is one possible explanation among many, and that it requires a blood test to confirm, not a TikTok diagnosis.

He also says "when your T is low, energy tanks by late afternoon" as if this is a documented, specific physiological pattern. It isn't. Circadian cortisol dips in the afternoon cause energy drops in virtually everyone, regardless of testosterone levels. Conflating a normal biological rhythm with a hormone deficiency is a stretch.

What he got right: TRT is not primarily about getting jacked. This is actually an important point to make in a space dominated by bodybuilding content. The Endocrine Society's clinical guidelines (Bhasin et al., 2018, Journal of Clinical Endocrinology and Metabolism) specifically define the goal of TRT in hypogonadal men as symptom relief and quality of life restoration, not performance enhancement. Framing TRT as a restoration tool rather than an optimization hack is clinically accurate.

What should you actually know?

If you're crashing every afternoon, get a full workup before you land on testosterone as the answer. That means a morning total testosterone draw (ideally two separate readings), plus thyroid-stimulating hormone, a complete blood count to rule out anemia, and a sleep evaluation if you snore or wake unrefreshed. The American Urological Association defines hypogonadism as a total testosterone level below 300 ng/dL accompanied by symptoms. The symptoms alone are not enough to diagnose or treat.

TRT does carry real risks that this video doesn't mention at all: suppression of natural testosterone production, reduced sperm count and fertility impact, elevated hematocrit (which raises clotting risk), and potential cardiovascular considerations that are still being studied post-TRAVERSE. These aren't reasons to avoid TRT if you genuinely need it, but they're reasons to have the conversation with a licensed clinician who reviews your full history, not a 30-second TikTok clip.

• A blood test is the only way to confirm low testosterone. Symptoms alone are not diagnostic.
• Afternoon fatigue has many causes. Ruling out sleep apnea, thyroid issues, and anemia first is standard clinical practice.
• TRT benefits for energy are real but modest, particularly in men with borderline-low levels.
• If you're considering TRT for energy, ask your provider about free testosterone, not just total testosterone, as binding proteins affect how much is biologically active.