TRT side effects: what TikTok gets wrong about the most common ones

What did @the.tudca.king actually say?

The creator claims that "the majority of people, even on TRT doses, will experience a raise in their hemoglobin and hematocrit," thickening their blood. They argue that doctors often pull patients off TRT because they cannot manage this side effect, and that blood donation as a workaround causes ferritin to crash. They then pitch a product called "Chemoflow" or "hematflow" as a solution, claiming it will "gradually bring your hematocrit levels under control whether you're running TRT or running full blown cycles."

The framing here is worth paying attention to. This is a product pitch dressed up as a clinical explainer. That does not automatically make the underlying claims wrong, but it does mean you should hold them to a higher standard.

Does the science back this up?

Partly, yes. Erythrocytosis is a well-documented, real side effect of testosterone therapy. But "the majority of people" is an overstatement that the evidence does not cleanly support.

Studies do show meaningful rates of elevated hematocrit in TRT patients. Bachman et al. (2010, Journal of Clinical Endocrinology and Metabolism) found hematocrit exceeding 50% in roughly 24% of men on testosterone therapy across several trials. A larger meta-analysis by Calof et al. (2005, Annals of Internal Medicine) put adverse hematocrit events at about 5.8% in treatment groups versus 1.2% in placebo. More recent data from the TRAVERSE trial (Lincoff et al., 2023, NEJM) confirmed elevated erythrocytosis risk in TRT users, but did not show this happening in the majority of participants. So yes, it is a real concern. No, it does not happen to most people.

The ferritin depletion point from repeated phlebotomy is also clinically real. Iron-deficiency from therapeutic phlebotomy is a recognized complication noted in hematology literature.

What did they get wrong (or right)?

They got the core biology right. Testosterone stimulates erythropoiesis through EPO stimulation and direct effects on bone marrow. Elevated hematocrit is a legitimate clinical concern on TRT. And yes, ferritin can drop with repeated blood donation. Those are accurate.

What they got wrong is the framing of frequency and severity. Saying "the majority of people" will develop thickened blood on TRT doses is not supported by the trial data. It conflates supraphysiologic use, which the creator obliquely references by mentioning "full blown cycles," with standard TRT dosing. Those are very different risk profiles.

More concerning is the product claim. The creator states their supplement will bring hematocrit "under control," which is a significant therapeutic claim. No peer-reviewed evidence is cited. No clinical trial on this specific product is referenced. Recommending an unverified supplement as a replacement for medical management of polycythemia, while suggesting that doctors are helpless to control this side effect, is misleading and potentially harmful. Elevated hematocrit in TRT patients is manageable through dose adjustment, dosing frequency changes, route-of-service modification, and in some cases phlebotomy. Framing doctors as having "no way to reliably control" it is simply inaccurate.

What should you actually know?

If you are on TRT and your hematocrit is elevated, this is a real clinical problem that deserves real clinical management, not a supplement. Hematocrit above 54% is generally considered a threshold for intervention in TRT patients, per Endocrine Society guidelines. Options your prescriber should be discussing with you include dose reduction, switching from injectable to transdermal delivery, extending injection intervals, or therapeutic phlebotomy with iron monitoring.

Ferritin depletion from phlebotomy is a legitimate concern and worth raising with your doctor. Some clinicians do monitor ferritin alongside hematocrit for this reason. But the answer is coordinated medical management, not switching to an unproven supplement.

The claim that doctors are powerless here is false. A good TRT prescriber has multiple tools. If yours is only offering "stop TRT" or "donate blood indefinitely" with no ferritin monitoring, that is a gap in your care worth addressing. It is not evidence that medicine has no answers.

Finally, the offhand mention of "full blown cycles" in the same breath as TRT management is a red flag. Anabolic steroid cycles carry substantially higher erythrocytosis risk than replacement-dose therapy. Conflating the two to sell a product is not a neutral clinical observation.