Thyroid Federation International – Statement
Thyroid hormone substitution: T4/T3 combination treatment and animal thyroid extracts
The standard treatment for hypothyroidism is levothyroxine (T4). In the majority of
people with hypothyroidism levothyroxine reverses their symptoms. Levothyroxine has
a long track record of safety and treatment can be monitored reliably by blood
tests. Because of the long duration of action, levothyroxine can be taken once daily.
Levothyroxine is a “pro-hormone” and is converted in the body to T3, the really
active thyroid hormone, which tissues and cells respond to.
Thyroid Federation International is concerned that many people with thyroid disease
feel that their symptoms are not well controlled. The information available in the
media on this topic may be confusing for patients. It includes suggestions of using
large doses of levothyroxine, T3, combinations of levothyroxine and T3 or desiccated
Thyroid Federation International believes that patients should be empowered by
being well informed about their condition and the various treatment options and
should take an active part in decision making about their treatment. Patients must
also be well informed about potential adverse effects of treatment options.
People who remain symptomatic on thyroid hormone replacement are an important
and medically challenging group who deserve to be taken seriously and managed
holistically. Within this group there are individuals with other medical diagnoses or
who have never achieved optimal thyroid hormone replacement with levothyroxine;
alternative means of thyroid hormone replacement may provide temporary
subjective improvement in symptoms, at the expense of long-term harm to their
health and may delay the diagnoses of other conditions. Many symptomatic
patients who have tried different thyroid hormone replacements fail to improve,
which is indicative of the fact that this approach is not a panacea for people who
are in that unfortunate category. For some people a trial of combination of T4 and T3
may prove to be beneficial. Thyroid Federation International endorses the European
Thyroid Association guidelines on this topic ( www.karger.com/Article/Pdf/339444 )
which provides a sound, responsible, safe and holistic framework (see Appendix 1).
Some people choose to take high doses of thyroid hormones or desiccated pig
thyroid. This choice should be respected – in such cases we believe that they should
have access to medical supervision and monitoring for potential development of
We believe that engagement between patients, scientists, doctors, patient and
medical professional organizations with an open mind is the best way of improving
patient outcomes and their quality of life. Our knowledge and understanding of
thyroid hormone replacement in people with hypothyroidism needs to be
broadened. Thyroid Federation International believes that more research is required
using robust scientific methodology.
May 25th, 2014
President of Thyroid Federation International
Dr. Petros Perros, Newcastle
Member of the TFI Medical Advisory Board
Background and practical information about combination of T4 and T3 based on the European Thyroid Association guidelines
Patients and doctors should have confidence and trust in each other, and have a
dialogue about the risks and benefits of the various treatment options.
Before embarking on a treatment plan including T4 and T3 in combination, the
following steps should be taken:
- The patient should have the benefit of optimal levothyroxine replacement
for a period of time, usually 6 months
- The patient should have a thorough physical assessment to exclude other
medical diagnoses, and an assessment of risk for osteoporosis and heart
- An evaluation of cognition and memory (“brain fog” etc.) should be
These examinations will provide a “baseline” of information.
Once started on this regime, it will require more frequent blood tests. The following
suggestions are made:
- If you begin this treatment and feel “hyper”, talk to your doctor immediately. It
may be necessary to stop the treatment.
- If you feel NO benefit, talk to your doctor, who will most likely recommend to
stop the combination treatment (risks may be higher than the benefits)
- If you have no hyper symptoms and feel better, continue. Stay in close
contact with your doctor and be diligent about lab work to avoid toxicity.
2012 ETA Guidelines: The Use of L-T4 + L-T3 in the Treatment of Hypothyroidism
Eur Thyroid J 2012;1:55–71 (DOI:10.1 159/000339444)