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Nature-Throid 1.75 Grain - 100 Tabs/Bottle

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Nature-Throid 1.75 Grain - 100 Tabs/Bottle

Nature-Throid 1.75 Grain

Product Name
Nature-Throid 1.75 Grain - 100 Tabs/Bottle
Active Ingredient
Levothyroxine T4 and Liothyronine T3
RLC Labs
Product Type
Thyroid hormone (thyroxine)
Product expiry date we are currently shipping
Discontinued, no stock
Stock Status
All Nature-Throid products are currently out of production with no estimate as to when they will be available again. We will update this notice if there is any news to report regarding product availability.

Nature-Throid tablets 113.75mg contain a combination of both forms of thyroid hormone levothyroxine (T4) and liothyronine (T3), and are used to replace the lack of thyroid hormone produced by an underactive thyroid, to treat the symptoms of hypothyroidism; also to treat thyroid goitre and thyroid cancer.

This product has been discontinued, but we do have alternatives below.

Nature-Throid general information

What is Nature-Throid used for?

Nature-Throid tablets 113.75mg (1¾ grain) are used to treat hypothyroidism or underactive thyroid, a condition in which the thyroid gland does not make enough thyroid hormone needed to regulate your body’s growth and metabolism.  Nature-Throid tablets 113.75mg are a natural replacement hormone, derived from pig thyroid gland, containing both forms of thyroid hormone (T3 and T4), which help to relieve the symptoms of hypothyroidism, including, tiredness, muscle weakness, cramps, feeling the cold, a slow heart rate, dry and flaky skin, hair loss, a deep husky voice and weight gain.  Nature-Throid tablets 1.75 grain can also be used to help treat hypothyroidism caused by surgical removal of, or damage to the thyroid gland, as well as treating thyroid goitre (enlarged thyroid gland) and thyroid cancer.  Another use for Nature-Throid tablets 113.75mg is for a suppression test, to test for thyroid activity. 

How does Nature-Throid work?

Nature-Throid tablets 113.75mg (1¾ grain) consist of an extract produced from pig thyroid glands which contains both forms of thyroid hormone; thyroxine (levothyroxine or T4) and liothyronine (L-triiodothyronine or T3).  Thyroxine (T4) is converted to the more active form of thyroid hormone (T3) in the liver, kidney and other tissues of the body and T3 interacts with a specific receptor inside cells to stimulate proteins needed to manage and control a variety of processes, including how the body regulates temperature, metabolises nutrients and controls growth and development.  Thyroid hormones regulate the production by the pituitary gland of another hormone called thyroid stimulating hormone (TSH), which in turn controls how much thyroid hormone is produced.  TSH also stimulates the growth of thyroid goitre (enlarged thyroid gland) and thyroid cancer.  Nature-Throid tablets  1 ¾ grain regulate TSH production in the same as way natural thyroid hormones and this is how it works when used for treating thyroid goitre or thyroid cancer by suppressing TSH production. 

What does Nature-Throid contain?

Nature-Throid tablets 113.75mg (1¾ grain) contain a desiccated (dried) extract of pig thyroid glands, which contains both forms of thyroid hormone; thyroxine (levothyroxine or T4 66.5mcg) and liothyronine (L-triiodothyronine or T3 15.75mcg) in the ratio 4.22:1 of T4 to T3, as T3 is approximately four times as potent as T4 on a microgram for microgram basis.  Nature-Throid tablets 113.75mg also contain colloidal silicon dioxide, dicalcium phosphate, lactose monohydrate, magnesium stearate, microcrystalline cellulose, croscarmellose sodium, stearic acid, Opadry II 85F19316 Clear. 

What does USP mean?

The thyroid extract in Nature-Throid tablets 113.75mg (1.75 grain) is known as Naturally Desiccated Thyroid (NDT) and is approved by the United States Pharmacopeia (USP) to give it full prescription status.  The USP standard covers pharmaceutical purity, hormone consistency and full testing procedures associated with quality prescription products.  This ensures that the amount of hormone activity in each Nature-Throid tablet is consistent. 

What doses of Nature-Throid are available?

Nature-Throid tablets are available in the following strengths:

    • 16.25mg thyroid extract (0.25 or ¼ grain) contains 9.5mcg levothyroxine (T4) and 2.25mcg liothyronine (T3)
    • 32.5mg thyroid extract (0.5 or ½ grain) contains 19mcg levothyroxine (T4) and 4.5mcg liothyronine (T3)
    • 48.75mg thyroid extract (0.75 or ¾ grain) contains 28.5mcg levothyroxine (T4) and 6.75mcg liothyronine (T3)
    • 65mg thyroid extract (1 grain) contains 38mcg levothyroxine (T4) and 9mcg liothyronine (T3)
    • 81.25mg thyroid extract (1.25 or ¼ grain) contains 47.5mcg levothyroxine (T4) and 11.25mcg liothyronine (T3)
    • 97.5mg thyroid extract (1.5 or 1½grain) contains 57mcg levothyroxine (T4) and 13.5mcg liothyronine (T3)
    • 113.75mg  thyroid extract (1.75 or 1¾grain) contains 66.5mcg levothyroxine (T4) and 15.75mcg liothyronine (T3)
    • 130mg thyroid extract (2 grain) contains 76mcg levothyroxine (T4) and 18mcg liothyronine (T3)
    • 146.25mg thyroid extract (2.25 or 2¼ grain) contains 85.5mcg levothyroxine (T4) and 20.25mcg liothyronine (T3)
    • 162.5mg thyroid extract (2.5 or 2½ grain) contains 95mcg levothyroxine (T4) and 22.5mcg liothyronine (T3)
    • 195mg thyroid extract (3 grain) contains 114mcg levothyroxine (T4) and 27mcg liothyronine (T3)

Treating underactive thyroid (hypothyroidism) with Nature-Throid

Nature-Throid tablets 113.75mg consist of an extract produced from pig thyroid glands which contains both forms of thyroid hormone; thyroxine (levothyroxine or T4) and liothyronine (L-triiodothyronine or T3) and are used to treat thyroid goitre, which is an enlargement of the thyroid gland.  If the thyroid gland cannot make enough thyroid hormone, usually due to an iodine deficiency, it grows to compensate for this, under the influence of thyroid stimulating hormone (TSH), produced by the pituitary gland.  TSH also stimulates the production of thyroid hormone, which in turn regulates the production of TSH in a hormone feedback cycle.  Nature-Throid tablets 1 ¾grain regulate TSH production in the same way and this is how it works when used for treating thyroid goitre, by suppressing TSH production so that the goitre can shrink in size.

What is the difference between natural and synthetic thyroid hormones?

Nature-Throid tablets 113.75mg (1 ¾grain) contain an extract produced from pig thyroid glands which contains both forms of thyroid hormone; thyroxine (levothyroxine or T4) and liothyronine (L-triiodothyronine or T3).  These hormones are therefore natural hormones, compared to synthesised hormones found in some other preparations of thyroid medication, which often contain only a single form of thyroid hormone.  Both natural and synthetic hormones work in the same way to treat thyroid disease. 

What are the side effects of Nature-Throid?

Most of the side effects experienced with taking Nature-Throid tablets 113.75mg (1.75 grain) indicate that your dose is too high and may need adjusting.  These include: headache, sleep problems (insomnia), feeling nervous or irritable sweating, flushing, appetite changes, weight loss, muscle weakness/cramps, tremors.

When should Nature-Throid not be used?

You should not use Nature-Throid tablets 113.75mg if you:

  • are allergic to thyroid hormones or any of the ingredients in Nature-Throid tablets
  • are looking for a treatment for obesity or to help you lose weight; this is not a weight loss product
  • have thyrotoxicosis (untreated high thyroid hormone levels) or adrenal gland problems
  • are pregnant, planning to become pregnant or breast-feeding
  • have a history of chest pain, heart attack, heart blood vessel problems, or other heart problems
  • are a diabetic taking antidiabetics or insulin, without discussion with your doctor, as Nature-Throid may affect your glucose tolerance
  • are taking other medications that may interact with Nature-Throid, such as anticonvulsants like phenytoin and carbamazepin, cardiac glycosides like digoxin, cholesterol-lowing drugs containing cholestyramine, antidepressants, anticoagulants like warfarin, oral diabetes medication such as acarbose, glipizide, glyburide or metformin, oestrogen containing contraceptives

What medications interact with Nature-Throid?

Several medications interact with Nature-Throid tablets 113.75mg (1¾ grain) and should either not be taken while you are taking Nature-Throid or only after discussion and instruction from your doctor:

  • Drugs that decrease effectiveness of Nature-Throid: antacids that contains aluminum or calcium or sucralfate (should be taken at least 4 hours apart from thyroid hormones); cholesterol-lowing drugs containing cholestyramine colestipol (should be taken at least 4 hours apart from thyroid hormones); iron supplement and vitamins with iron (should be taken at least 4 hours apart from thyroid hormones); oestrogen containing contraceptives
  • Drugs that are affected by Nature-Throid: anticoagulants, like warfarin because the risk of bleeding may be increased; insulin or an oral diabetes medication such as acarbose glipizide glyburide metformin

How should Nature-Throid be taken?

You should take your Nature-Throid tablets 113.75mg (1¾ grain) swallowed whole with a glass of water on an empty stomach, preferably 30 minutes before a meal.  The dose of Nature-Throid that you take depends on your personal levels of thyroid hormone, what you are being treated for, and should be as recommended by your doctor.  The usual starting dose is 32.5mg Nature-Throid, with increments of 16.25mg every 2 to 3 weeks, depending on the levels of T3 and T4 measured in your blood during treatment, so blood monitoring is important while you are taking Nature-Throid.  It usually takes several weeks to see normal levels of blood thyroid hormone levels after starting treatment and you may need to take Nature-Throid for the rest of your life.   

How long should you take Nature-Throid?

Since Nature-Throid tablets 113.75mg are used to replace a thyroid hormone deficiency this is a long-term treatment and may be for the rest of your life. 

Missed dose of Nature-Throid

If you miss a dose of Nature-Throid tablets 113.75mg (1¾ grain) take it as soon as you remember, unless it is time to take the next dose, then skip the missed dose.  Do not take a double dose.

How should Nature-Throid be stored?

You should store your Nature-Throid tablets 113.75mg below 25°C in a cool dry place. 


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