What did @drsteveng actually say?
The core claim here is that testosterone raises red blood cell production, and without monitoring, hematocrit can climb high enough to make blood "more like ketchup than red wine," increasing stroke risk. He also argues that insulin resistance should be addressed before jumping to TRT, and that skipping lab monitoring is, in his words, "malpractice."
He's directing this at clinicians, which is worth noting. The framing is less "here's what patients should do" and more "here's what prescribers are getting wrong." That changes how we should evaluate this. The concern about unmonitored testosterone use from online platforms is the real headline of this video, and it's a legitimate one worth scrutinizing carefully.
Does the science back this up?
Mostly, yes. Testosterone-induced erythrocytosis is well-documented and not especially controversial. The mechanism is real: testosterone stimulates erythropoietin production and directly acts on bone marrow progenitor cells to increase red cell mass. Hematocrit elevations above 54% are flagged in clinical guidelines as a reason to pause or reduce TRT dosing.
The stroke link is where things get more complicated. Epidemiological data is genuinely mixed. A 2023 meta-analysis by Sharma et al. in JAMA Network Open found no significant increase in cardiovascular events in men on TRT with proper monitoring. But a 2010 study by Basaria et al. in NEJM found elevated cardiovascular event rates in older men on testosterone, though that trial was stopped early and had methodological critiques. The TRAVERSE trial published in 2023 in NEJM by Lincoff et al. found TRT was non-inferior to placebo for cardiovascular events in hypogonadal men with elevated cardiovascular risk, but did not specifically isolate hematocrit-driven strokes as a subgroup outcome. The honest read: high hematocrit from TRT is a plausible stroke mechanism, but the direct causal evidence in humans is observational and incomplete.
What did they get wrong (or right)?
He gets the physiology directionally right. Testosterone does increase bone marrow activity and red cell production. The "ketchup vs. red wine" analogy is crude but mechanistically defensible as a way to explain hyperviscosity to a lay audience.
Where he oversells it: "it happens more often than you think" is unquantified and frankly not supported by solid prevalence data. The Endocrine Society and AUA guidelines do flag erythrocytosis as a monitoring concern, but neither cites stroke as a common adverse outcome of TRT at population level. Saying it "happens a lot" without a number is the kind of vague alarm that makes people fear legitimate therapy unnecessarily.
His point about insulin resistance being addressed before initiating TRT is actually well-grounded. Insulin resistance suppresses sex hormone-binding globulin, which can depress total testosterone readings. Improving metabolic health first is a reasonable clinical sequence supported by data from Camacho et al. (2013, Journal of Clinical Endocrinology and Metabolism). That part deserves credit.
Calling monitoring failures "malpractice" is loaded language. It may reflect genuine clinical frustration, but malpractice has a legal definition, and blanket application here is imprecise.
What should you actually know?
If you are on testosterone therapy through any provider, your hematocrit should be checked before starting and at regular intervals, typically at 3 and 6 months, then annually if stable. This is not optional and any legitimate prescriber should be doing it automatically.
The threshold most guidelines use is a hematocrit above 54%. At that level, clinicians typically reduce the dose, extend the dosing interval, or recommend therapeutic phlebotomy. The goal is not to avoid TRT entirely but to manage it properly.
The concern about direct-to-consumer testosterone platforms skipping these labs is real. A 2021 review by Bhasin et al. in NEJM specifically noted that the rise of telehealth testosterone prescribing had outpaced the implementation of standardized monitoring protocols. That gap is the actual public health issue this video is pointing at, even if the stroke framing overstates the certainty of that risk.
If you have insulin resistance or obesity and your testosterone is low, improving those conditions first is worth trying. It may normalize testosterone without exogenous supplementation. That is not anti-TRT ideology, it is good clinical sequencing.