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Articles on Thyroid


The Role of Thyroid in the Hormonal Cascade
Is your low thyroid really low, or is its function just blocked?


The Thyroid Manufactures

  • Thyroid Hormone (TH)

    • Thyroxine (T4)

    • Triiodothyronine (T3)

These govern metabolic rate

  • Calcitonin

    • A peptide that affects bone calcification

Many women report being diagnosed with hypothyroidism (low thyroid) after they have started estrogen supplements. They also often report weight gain, breast swelling, thinning hair, and gall bladder disease, all signs of potential estrogen dominance and progesterone deficiency, according to John R. Lee, M.D.

Dr. Lee’s advice to women who have been diagnosed with hypothyroidism and who are taking unopposed estrogen was to reduce their estrogen dose by at least 50% and use progesterone cream. Dr. Lee reported that as estrogen dose decreased and progesterone levels were restored, symptoms of hypothyroidism lessen or disappear. Often, he discovered that thyroid supplement were no longer needed by many women.

Dr. Lee saw hundreds of women who had been diagnosed with hypothyroidism and reported that he learned that “estrogen dominance can block thyroid hormone function and that progesterone promotes or normalizes hormone function. What appears to the doctor to be hypothyroidism is often merely another face of estrogen dominance.”

About the Thyroid Gland

The butterfly-shaped thyroid gland is located in the anterior neck, lies across the trachea at the base of the throat. It is the largest pure endocrine gland in the body. It produces two substances: thyroid hormone and calcitonin. Thyroid hormone produces thyroxin (T4) and a lesser amount of triiodothyronin (T3) from iodine and the amino acid tyrosine. T3 has 3 iodine atoms and T4 has four iodine atoms. Thyroid hormones affect many target cells in the body and its main function is to increase basal metabolic rate (BMR). Calcitonin lowers blood levels of calcium by slowing calcium releasing activity of osteoclasts in the bone and increasing calcium secretion by the kidney.

Low thyroid effect may cause lower body temperature, weight gain and lack of energy.

Other common hypothyroid symptoms include: dry skin/hair, brittle nails, headaches, foggy thinking, constipation, and puffy face/eyes. In many people with low thyroid the symptoms are subtle and are often not recognized.


Thyroxin (T4)


Thyroid is the Second Most Refilled Drug Prescription for Women in the United States, behind Hormone Replacement Therapy

Statistically, about 10% of the general population is hypothyroid, but about 5 times more women than men are hypothyroid. About 20% of women over age 65 are diagnosed as hypothyroid. These statistics gave Dr. Lee his clue that thyroid is connected in some way to estrogen, progesterone and the other steroid hormones.

Of the top 200 best-selling drugs in the U.S in 1996, the thyroid supplement Synthroid was number 3, and in 1998 it was number 2 (after Premarin) on the most refilled drug prescription list.

Dr. Lee believed that women diagnosed as hypothyroid often have normal T3 and T4 levels but their TSH (thyroid stimulating hormone) is high. The elevated TSH may indicate thyroid hormone deficiency, or it may indicate that something is inhibiting the function of thyroid hormone. He stated “since so many more women than men have “hypothyroidism,” it is more likely that an elevated TSH with normal range T3 and T4 in women indicates not thyroid deficiency but merely that estrogen dominance is blocking thyroid hormone function.”

Progesterone and Hypothyroid Symptoms

The symptoms of progesterone deficiency and hypothyroidism can be very similar. If a woman is pre-menopausal, estrogen production is usually sufficient. In general if you are menstruating, you have adequate estrogen. In women who have regular periods, doctors may assume that, despite normal T3 and T4 levels, fatigue and low basal temperature indicate hypothyroidism. However, progesterone is anabolic and thermogenic so that a deficiency causes weight gain and low temperature. Progesterone deficiency is often the true culprit. According to Dr. Lee, some women do need a little thyroid supplementation, but the incidence is much lower than is generally thought,

Thyroid Supplements

The choices of thyroid supplements are Armour, which is group up or desiccated cow or pig thyroid (USP thyroid) or thyroxin (levothryoxine sodium), with the most common brand names of Levoxyl and Synthroid. Armour supplies T3 and T4 in approximately the ratio made by the human thyroid and this is the supplement recommended by Dr. Lee as being most natural. You might want to ask your doctor about it.

Thyroid is a prescription-only drug and your doctor should monitor your dosage and test your levels every 6 months.

Other Thyroid Blockers
(From the research of John R. Lee, M.D.)

  • Many prescription drugs can block or decrease levels of one or both thyroid hormones. The most common include prednisone, barbiturates, oral contraceptives, cholesterol-lowering drugs, heparin, phenytoin (Dilantin), propranolol, and aspirin.

  • Soy can block thyroid. Some women are eating soy products such as tofu and tempeh, taking soy protein powders, drinking soy milk, eating soy “energy” bars, and taking soy supplements for their phyto-estrogenic effect – every day! This can lead to blocked thyroid function. Soy should be eaten in moderation. Eating soy a few times a week should be plenty and the best source are fermented soy such as miso, tempeh and tofu not processed soy.

  • If you eat excessive amounts of the cruciferous vegetables such as broccoli, cauliflower, cabbage, and Brussels sprouts, you can also block thyroid function. A few times a week is plenty.