T3 Therapy Side Effects: What the Manual Says

Anyone considering T3 therapy should read what its proponent says can go wrong before reading what he says can go right. Dr. Wilson’s doctor’s manual is unusually direct about side effects — what they feel like, what he thinks causes them, who should not be treated, and the rule he gives physicians for any complaint at all. This guide collects those passages. It is not reassurance and it is not a warning; it is his account, with the critics one click away.

His rule for any side effect

T3 therapy is not a “no pain, no gain” approach. Patients should not have any complaints and should only feel better. Any complaints, even if mild, simply indicate that the T3 levels are not sufficiently normal and steady, so the T3 therapy should be adjusted to eliminate them. Also, a patient with mild complaints is that much closer to having more severe complaints, and it is best to stay as far away from such complaints as possible.

— Caveats for T3 Therapy, the doctor’s manual

What the side effects feel like

As mentioned previously, a person may get characteristic side effects if the T3 levels become unsteady. A lot of what people think are symptoms of thyroid toxicity are really due to thyroid hormone level unsteadiness.

The most common side effect is fluid retention, not severe pedal edema, but a little bit of fluid retention and puffiness in the hands that can cause some achiness, and tightness of the rings. Patients can also complain of dull headache, edginess, irritability, and then increased awareness of the heartbeat and/or increased heart rate. Patients sometimes describe the side effects as feeling flu-like.

— Unsteadiness and the T4 Test Dose, the doctor’s manual

What he says causes them

His position is that the trouble is unsteady levels rather than too much hormone — and it is a position, not a consensus:

Very much of what people consider to be symptoms or side effects of T3 or T4 toxicity in terms of excessive thyroid hormone levels is really due to unsteady thyroid hormone levels.

And the distinction can be made pretty well by determining if the person’s temperature is above or below normal, and by use of a T4 test dose.

— Unsteadiness and the T4 Test Dose, the doctor’s manual

The major cause of side effects with T3 therapy is unsteady T3 levels. Two major factors contribute frequently to unsteady T3 levels. The first is patients not being very compliant with the treatment (especially in terms of taking their medicine very much on time-see p102). The second is not taking deliberate control of a person’s thyroid system, especially in rapid compensators (p94). The secret is to start the T3 therapy steadily, in patients with steady T3 levels, and to keep the T3 therapy and T3 levels as steady as possible from the start.

— Caveats for T3 Therapy, the doctor’s manual

This is why the protocol insists on a sustained-release preparation taken exactly on time; the reasoning is collected in Sustained-Release T3 vs Cytomel.

The risk he names: cardiovascular

The manual’s Q&A answers “what are the substantive risks?” at length. The core of it:

T3 is a molecule that is present from birth in every human’s body, and is absolutely necessary for good health. There is nothing inherently bad about the molecule-our lives depend on it. It can’t and hasn’t directly damaged the tissue of your heart, brain, or other tissues. There is not a shred of evidence that suggests that thyroid hormones, when used properly, can damage the body in any way. But T3 is not candy, and T3 therapy is not completely without risk, as nothing is. The major consideration in terms of risk is cardiovascular.

The whole trick to T3 therapy is keeping the T3 levels steady. Unsteady T3 levels can increase a patient’s chances of increased heart rate, and palpitations. And if a patient is already on the verge of having a heart attack or a stroke, these cardiovascular side effects could aggravate the situation (p142). In some cases it is difficult to avoid unsteady T3 levels, and so it might not be advisable to implement T3 therapy in those patients who may not have the cardiovascular reserve to tolerate unsteady T3 levels very well (for example, certain elderly patients) (Q17).

— T3 Therapy Questions and Answers for Doctors, the doctor’s manual

Note what that passage does and does not claim. It denies direct tissue damage; it does not deny risk, and it names the patients he would not treat.

Two more things he says about risk

T3 therapy is not addictive, and does not necessarily need to be taken for life. With proper T3 therapy, one does not expect drastic problems, because one does not make drastic changes, and any side effects are addressed early.

— T3 Therapy Questions and Answers for Doctors, the doctor’s manual

Severe side effects rarely, if ever, come on all at once, without warning. Side effects tend to appear and worsen gradually, progressively.

It is not wise to decrease the T3 therapy too quickly or to stop it abruptly, lest the patients’ own thyroid systems are not given enough time to come back up and support their metabolisms.

— Caveats for T3 Therapy, the doctor’s manual

That last point matters for patients: in his account, stopping suddenly is itself a way to feel bad. Any change is the prescriber’s to make.

How he tells a side effect from the flu

The manual describes a physician’s tool — a small dose of T4 given as a test — and a story about it:

This test dose is so often effective that it can almost be considered to be an antidote for T3 unsteadiness (which is why I called it a litmus test for unsteadiness).

Note: In a typical case, there was no improvement (in her symptoms suspicious for T3 unsteadiness) after 45 minutes or so, and I told the patient I felt that it was extremely unlikely that her symptoms could be related to the T3 she was taking. The following day she called to say: “You were right Dr. Wilson, everyone in my family has come down with the flu and so have I, I don’t think it was the T3.” When her flu cleared, so did her complaints of achiness, fatigue, and edginess.

— Unsteadiness and the T4 Test Dose, the doctor’s manual

The details of that tool are in the chapter, for physicians; they are not repeated here.

Who he says should not be treated

Beyond the cardiovascular caution above, the caveats open with a simpler exclusion:

I do not feel that T3 therapy is necessary if a patient is not symptomatic even if the temperature runs below 98.6.

Before therapy is started, and at each step along the way, the patient and physician must carefully weighs the pro’s and the con’s, and all the alternatives to T3 therapy. If the pro’s of T3 therapy do not outweigh the con’s, then of course T3 therapy should not be started, or if it has been started it should be gradually (not necessarily slowly-see c22) weaned.

— Caveats for T3 Therapy, the doctor’s manual

The other side

The American Thyroid Association’s objection is not to side effects of T3 as such; it is that the diagnosis itself is not established and that treating a “normal” thyroid with hormone carries risk without demonstrated benefit. The objection hub names and links the ATA, Cleveland Clinic and Wikipedia, and then gives Dr. Wilson’s answers. The protocol’s published record is small — an eleven-patient report and a clinical-experience paper — and is described as such on the author page.

Physicians will want the chapters themselves: Unsteadiness and the T4 Test Dose, Risks, Benefits and Myths, and the Caveats.

This is a reader’s guide compiled from Dr. Wilson’s published writing; every quotation is his and links to its source. T3 is a prescription medicine; nothing here is a dosing instruction, a reassurance, or medical advice.