Thyroid hormone extract

Copyright 2015  All rights reserved   •
This site is still
a work in progress. 
Please email
with corrections or comments
Thyroid hormone extract, also referred to as natural dessicated thyroid
(NDT), is a usually porcine extract, although sometimes it is bovine. It
contains thyroxine (T4) and a small amount of triiodothyronine (T3). For
someone who does not have a low ratio of free T3 (FT3) to reverse T3
(RT3), it should be the medication of choice.
There are many brands, and individual preferences vary. Different
brands of thyroid hormone extract are made with different fillers which
may account for one working better for an individual than another. The
original brand, Armour®, has been reformulated in recent years and is
not as well liked as it once was. Other brands that are reported to work
well are Nature-throid®, Erfa and Thyroid-S.® Thyroid-S may be a bit
higher in T3 than others
Most of the products are prescribed by “grain.” One grain is 60 or 65
mg, depending on the brand. Each grain contains approximately 9 mcg
T3 and 38 mcg T4. Most people need around three grains to feel their
best, but it is not uncommon for an individual to need as much as five
grains and others may need less.
Thyroid hormone extract is prescribed based on the need for
exogenous thyroid hormone. It is started with a low dose such as .25 or
.5 grain and increased at two to four week intervals. The T4 in it builds
up slowly and accurate testing usually requires being on a dose for
approximately six weeks.
Thyroid hormone extract can be taken sublingually. It can also be
crushed before being taken sublingually or swallowed. When
swallowed, it is taken without food and one hour before or two hours
after eating or drinking anything except non-fluoridated water; some
recommendations require only 20 to 30 minutes before eating. Taking it
sublingually negates the requirement to take it away from food.
For best results, it should be dosed at least twice a day, waking and six
hours later or waking and bedtime.
A note about synthetic T4
The thyroid treatment of choice among mainstream medical
practitioners has for many years been synthetic levothyroxine or T4
(brands Synthroid®, Levothroid®, Tirosint®, Unithroid®, Levoxyl®,
Novothyrox®). The drug was introduced prior to the FDA requiring
testing and approval was “grandfathered.” It has never been proven in
any long-term study to resolve hypothyroid symptoms. Although it may
be a somewhat effective treatment for some hypothyroid individuals,
anecdotal evidence indicates it is rarely optimal and we do not
recommend its use.