"…euthyroidism is not restored in plasma and all tissues of thyroidectomized rats on T4 alone. These results may well be pertinent to patients on T4 replacement therapy."

"I would…suggest that all hypothyroid patients require both their T4 and T3 bloodlevels to be in their mid- to high-normal ranges. If T4-only treatment provides these levels, fine; if not, T3 needs to be added to the treatment."

"In patients with hypothyroidism, partial substitution of triiodothyronine [T3] for thyroxine [T4] may improve mood and neuropsychological function; this finding suggests a specific effect of the triiodothyronine normally secreted by the thyroid gland."

"...if natural thyroid is not to be used, then at least T4 should be combined with T3 for a more satisfactory and more logical replacement."

"T4 is converted to T3 at cellular level by a specific enzyme. T4 is not actually used by the cells. T3 is the active hormone. It seems clear that the enzyme that changes T4 to T3 may be deficient, causing symptoms of hypothyroidism even in people who have normal T4 levels. These patients need to take T3."

"…this [T4 only] mandate is not scientifically based. Instead, it's based on a powerful marketing campaign of a major pharmaceutical company….As a result, they [conventional endocrinologists and thyroid specialists] 've deprived themselves of clinical experience with any thyroid preparation other than T4."

"If the Free T3 level is significantly lower than the Free T4 level, it is next to useless to treat with Synthroid/ Levoxyl/Levothroid (T4) only replacements. If the patient could not muster sufficient T3 from their gland (which produces some T3 directly), then they are certainly not going to convert enough T3 from T4 only. Traditional medicine assumes that preparations like Synthroid which are T4 only converts peripherally in the body to T3 in fairly standard amounts and at fairly standard rates. Unfortunately, clinical experience shows this is not true for the majority of patients. Consistent measuring of both free T3 and free T4 blood levels in hypothyroid patients who are on T4 only therapy will very rapidly dispel this myth. A certain percentage of hypothyroid patients do convert enough T4 to T3 at a sufficient rate for T4 treatment to be adequate as a source of T3; but a substantial proportion of patients require some combination of both exogenous T3 and T4."

"…some people become depressed when they take just T4 and their depression can be cured when they take both thyroid hormones, T3 and T4."

"The endocrinology establishment has also argued against treatment with any T3, even in combination preparations…namely that each morning/ daily treatment dose would cause peaks in the afternoon that are too high, and valleys at night and in the morning that are too low. It never seems to occur to them that this objection is very easily overcome by prescribing all T3-containing preparations either after breakfast and supper daily OR on an empty stomach every 8 hours…."

"In my experience, Armour Thyroid provides the best results for the majority of patients. Armour thyroid not only contains T3 and T4, but it contains many other factors that facilitate the conversion of T4 to T3 including calcitonin, T1, T2 and many other chemicals that we have not even identified."

"The ideal thyroid replacement would be natural human thyroid in exactly the right proportions. However, since this is not currently available I use the desiccated animal product because it seems to work well for most patients, much better certainly than synthetic T4 alone (Synthroid)."

"There is not much danger of over-treatment if all you are trying to do is 'put the TSH and, perhaps the T4 level, in its normal range' because you are sailing 'far from the edge' in that case. But your patient is going to suffer the overall disadvantages of continuing to run a low-normal, sub-optimal level of both hormones. In my view, these disadvantages… are far, far greater than the potential dangers of over-treatment, if one knows how to prescribe T3 and monitors the FT4 and FT3 levels regularly."

"I have found that many hypothyroid patients also have cellular resistance to thyroid hormone. Most of these patients don't benefit much from T4 alone, but some of them do from desiccated thyroid, presumably because of the relatively high T3 content. Some we have to switch to synthetic T3 because they don't benefit from desiccated thyroid. We've stopped altogether giving patients T4 alone."

"…some hypothyroid patients whose symptoms fail to respond to T4 alone have a rapid and marked improvement when their treatment is changed to an equivalent dose of thyroid extract (such as Armour thyroid)."

"Many people have a normal or even LOW-normal TSH level, yet still suffer continuing hypothyroidism symptoms. In these cases, the addition of T3 helped relieve depression, brain fog, fatigue and other symptoms."

"Meanwhile, if doctors like Toft, Greenspan, Yeo and their colleagues have their way, patients may wait forever for the big enough, long-enough, peer-reviewed-enough study that proves what the research has already shown, and patients already know. Thyroid patients have wasted enough valuable time not feeling well, living lives at half-speed, waiting to feel better, while doctors tell us that more research is needed. They could literally research our lives away. We already have the research findings that can help many people. And we have the anecdotal knowledge of thousands upon thousands of thyroid patients and their doctors who are able to live well with the use of T3 drugs. Thyroid patients have waited long enough. Responsible doctors owe it to their patients to carefully consider whether or not T3 will benefit their patients."

"Many people continue to suffer from symptoms of low metabolism. They have difficulty losing weight, and they complain of hair loss, dry skin, brittle nails, muscle cramps, and a host of physical symptoms. These symptoms indicate that the body is not receiving exactly the right amount of T3 from the conversion of T4. Many people suffer from some degree of depression, also probably due to some extent to low T3 in the brain."