What Doctors Don't Tell You About Your Thyroid | Dr. Amie Hornaman

Elevated reverse T3 and non-optimized thyroid function impair the immune system's ability to destroy cancer cells.

"It's the fact that these poor people on T4 only with elevated reverse T3 and nonoptimized thyroids don't have the immune system working enough to destroy cancer cells." (said at 0:30:07)

No published record matching the claim that T4-only therapy, elevated reverse T3, or non-optimized thyroid status impairs the immune system's ability to destroy cancer cells was located; this does not prove the claim false. While T3 (liothyronine) has been investigated experimentally as a potential small-molecule blocker of the TIGIT/PVR immune checkpoint (PMID: 32894141), there is no established clinical or mechanistic evidence establishing that elevated reverse T3 in patients on T4 monotherapy causes immunosuppression that prevents immune clearance of cancer cells.

• context: Repositioning liothyronine for cancer immunotherapy by blocking the interaction of immune … (Cell communication and signaling : CCS 2020) · cited 32x in the literature

  "A small molecule liothyronine was discovered to serve as a potential candidate for cancer immunotherapy by blocking the immune checkpoint TIGIT/PVR." (abstract, conclusions, passage verified)

  pubmedfull study (doi)

Elevated insulin, elevated cortisol, liver dysfunction, gut dysbiosis, and micronutrient deficiencies drive increased conversion of T4 into reverse T3.

"Well, what are the drivers of reverse T3? Elevated insulin from eating like garbage, elevated cortisol—you're all stressed out and wigged out or you just have environmental stressors that are throwing off your adrenals—your liver, your gut, huge, huge places of conversion. So, how many livers are gunked up? How many guts are messed up? Micronutrient deficiencies. There's so many things that get in the way of that T4 to T3 conversion" (said at 0:51:20)

No published record matching the claim that elevated insulin, elevated cortisol, liver dysfunction, gut dysbiosis, and micronutrient deficiencies drive increased conversion of T4 into reverse T3 was located; this does not prove the claim false.