TRT and blood clots: separating real risk from panic

What did @socalurologyinstitute actually say?

The creator responded to a viewer who had a pulmonary embolism (PE) and is on lifelong anticoagulation. His core claim: if you're already on a blood thinner, "you're not going to get another clot," making TRT safe to add. He qualifies this by saying to ask your hematologist, but then immediately undercuts that by asserting the answer is definitively "yes" before the consultation happens. He also says "most doctors don't understand why people get blood clots," which is a sweeping claim doing a lot of work in this video. The framing is reassuring to a degree that should make careful viewers pause. Confidence is not the same as certainty, and this video leans heavily on confidence.

Does the science back this up?

Partially, but the picture is messier than presented. Testosterone does increase erythropoiesis, raising hematocrit, which increases blood viscosity and, in some patients, thrombotic risk. The FDA added a warning about venous thromboembolism (VTE) to testosterone products in 2014 specifically because of this mechanism. Studies like Glueck et al. (2014, Clinical and Applied Thrombosis/Hemostasis) documented cases of VTE in men on TRT, particularly those with underlying thrombophilias. However, the picture for anticoagulated patients is different. If someone is on therapeutic anticoagulation, the clotting cascade is actively suppressed, which does meaningfully reduce the risk that testosterone-driven erythrocytosis triggers a new clot. A 2023 review in the Journal of Sexual Medicine acknowledged that anticoagulated patients represent a distinct risk category where TRT may be considered, though prospective data in this specific population remains limited. The creator's conclusion isn't baseless, but presenting it as settled is an overreach.

What did they get wrong (or right)?

Credit where it's due: recommending hematologist consultation is appropriate, and the physiological logic behind anticoagulation reducing recurrent VTE risk is sound. But several things here are wrong or oversimplified. First, "you're not going to get another clot" is too absolute. Anticoagulants reduce recurrence risk substantially but do not eliminate it. EINSTEIN-PE trial data (Bauersachs et al., 2010, NEJM) showed rivaroxaban reduced recurrence rates versus standard therapy, but recurrence still occurred in treated patients. Second, the claim that "most doctors don't understand why people get blood clots" is dismissive of hematology and is the kind of statement that builds misplaced trust in one provider's opinion over a broader care team. Third, the video makes no mention of polycythemia monitoring, which is standard of care when TRT is prescribed, particularly in patients with a clotting history. That's a real omission. The mechanism linking testosterone to VTE isn't just theoretical, and patients with prior PE need closer hematocrit surveillance, not a blanket reassurance.

What should you actually know?

If you've had a PE or DVT and are considering TRT, the conversation with your care team needs to include a few specific things the video skips. Your underlying reason for clotting matters enormously. Inherited thrombophilias like Factor V Leiden or prothrombin gene mutations change the risk calculus significantly. Glueck et al. (2014) found that many men who developed VTE on TRT had undiagnosed hypercoagulable states. Being on a blood thinner is protective but not a green light without workup. You should also know that route of administration may matter. Injectable testosterone tends to produce higher and more variable hematocrit increases than transdermal formulations, which is worth discussing with your prescriber. Regular CBC monitoring to track hematocrit is standard and non-negotiable in any patient with a clotting history starting TRT. The creator's overall message, that prior clot history plus anticoagulation does not automatically rule out TRT, is defensible. The delivery, which sounds like a verdict rather than a starting point for a nuanced clinical conversation, is the problem.