Does testosterone therapy actually boost energy levels?

What did @mike.moosbrugger actually say?

The claim is straightforward: testosterone helps your body make red blood cells, low testosterone means fewer red blood cells, less oxygen reaches muscles and the brain, and that explains why men with low T feel winded or fatigued. The conclusion is that "testosterone therapy actually increases red blood cell count and can boost energy naturally."

That's the core argument. It's presented as a tidy biological chain reaction, which makes it easy to follow, but also easy to oversimplify. Credit where it's due: the basic physiology here isn't fabricated. But the framing leaves out some things that matter quite a bit clinically.

Does the science back this up?

Partially, yes. Testosterone does stimulate erythropoiesis, the production of red blood cells, primarily by increasing erythropoietin (EPO) production in the kidneys and by directly stimulating bone marrow. This is well-established. The problem is that the video presents increased red blood cell count as a clear benefit. Clinically, it's more complicated than that.

A 2010 meta-analysis by Calof et al. in the Journals of Gerontology found that testosterone therapy was associated with significantly elevated hematocrit, which sounds good until you realize elevated hematocrit increases blood viscosity and raises the risk of polycythemia, a condition linked to cardiovascular events including stroke and deep vein thrombosis. The 2023 TRAVERSE trial (Lincoff et al., New England Journal of Medicine) confirmed that TRT in middle-aged and older men did not increase major cardiovascular events overall, but polycythemia was among the notable adverse effects requiring monitoring. So yes, testosterone raises red blood cell count. Whether that's a net benefit depends heavily on the individual and how it's managed.

What did they get wrong (or right)?

The physiology is mostly right. Testosterone does stimulate red blood cell production, and low red blood cell counts can contribute to fatigue and reduced exercise tolerance. Hypogonadal men do often report feeling fatigued, and studies like Buvat et al. (2013, Journal of Sexual Medicine) confirm that TRT can improve energy and vitality in men with clinically confirmed low testosterone.

What's wrong is the framing. Saying TRT "can boost energy naturally" glosses over a few things. First, "naturally" is doing a lot of work here. Injecting synthetic testosterone or applying a pharmaceutical gel is not a natural process. Second, the video implies that increased red blood cell count is straightforwardly beneficial, without mentioning that it requires monitoring and can become dangerous if hematocrit climbs too high. Third, fatigue in men is rarely caused by low testosterone alone. Thyroid dysfunction, sleep apnea, depression, and metabolic issues all produce similar symptoms. A red blood cell narrative is too narrow an explanation.

• The testosterone-erythropoiesis link: accurate
• Low T causing fatigue and being winded: plausible but overly simplified
• Increased red blood cell count as a straightforward energy benefit: misleading without context
• "Naturally": a word choice that misrepresents what TRT actually is

What should you actually know?

If you're fatigued and you're wondering whether low testosterone is the cause, the first step is a blood test, not a TikTok. Clinically confirmed hypogonadism, meaning low serum testosterone with accompanying symptoms, is a legitimate medical condition that TRT can help. But fatigue has many causes, and self-diagnosing based on feeling tired is not a reliable pathway to appropriate treatment.

The red blood cell piece is real, but it cuts both ways. Men on TRT are typically monitored for hematocrit levels precisely because erythrocytosis is one of the more common adverse effects. Guidelines from the Endocrine Society recommend checking hematocrit before starting TRT and at regular intervals during treatment. If hematocrit exceeds around 54%, dose adjustment or temporary cessation is usually indicated. That's not a detail you want to skip because a TikTok told you increased red blood cells means more energy.

Bottom line: the mechanism described is real, the outcome is real in the right patient population, and the risk profile deserves equal airtime.