Introduction
So, I’ve been hearing and reading about the fascinating interplay between thyroid hormone and sex hormones (Sex hormone binding globulin, total testosterone, total estradiol, free androgen index). Clearly, the fitness and bodybuilding community is diving headfirst into this discussion, with some folks even contemplating a career as a “professional hypothyroid” for the potential androgenic perks. This discussion piqued my curiosity, leading me to embark on a deep dive into the subject. And yes, you betcha, I’ve discovered that thyroid hormones can indeed tango with your sex hormones, and can increase testosterone. If you need a bit of background info, feel free to read about my thyroid saga.. Now, let’s unravel the mysteries of thyroid conditions and their unexpected anabolic effects
What Does the Thyroid Do?
Picture this: your brain as the ultimate puppet master. The pituitary gland, nestled in your brain, releases Thyroid Stimulating Hormone (TSH). TSH is essentially the messenger that struts down to your thyroid and yells, “Start making those thyroid hormones!” With TSH’s enthusiastic guidance, the thyroid conjures up a dynamic duo: Thyroxine (T4) and Triiodothyronine (T3). T4 is mad in higher abundant. But wait, T4 has a trick up its sleeves! When your body craves more T3, T4 can pull off a nifty transformation into T3. These dynamic hormones make their grand entrance into your bloodstream, orchestrating a symphony of bodily functions. All the thyroid needs to create these hormones are a few key ingredients: iodine and amino acids (especially tyrosine).
A Few Tricks Up Their Hormonal Sleeves
Thyroid issues are like the unsung heroes of health problems, quietly pulling strings behind the scenes. It is estimated that 1 in 20 people in the UK have a thyroid problem, with similar estimates in the USA. Thyroid hormones control so many of the bodies functions and they seem to be able to pull off some serious behind the scenes magic.
Temperature Control
The eternal struggle between being too hot and too cold? Blame it on these masterminds. If you have an overactive thyroid, you’ll be rocking shorts in a blizzard. An underactive thyroid? You’ll need a personal space heater. Source.
Metabolism Magic
With a flick of a hormonal switch, thyroid hormones control the rate at which your body burns energy. Its magical ability dictating how fast or slow energy is burned. As these hormones increase so does metabolic rate. It’s their duty to decide if you have the energy of a Duracell bunny or a sloth. Source.
Mood Management
They also have mood management skills, it’s the hormone responsible for ensuring your mood stays steady. thyroid hormones have an interconnection with neurotransmitters serotonin and dopamine, which are responsible for feeling of wellbeing, happiness and motivation. Therefore when this hormone is unstable, so are you! Source.
Nutrition Navigation
Thyroid hormones have a job to maintain a balanced metabolic rate to ensure that the calories consumed match the body’s energy expenditure. Therefore when thyroid function is out of whack it can lead to weight related issues. Mess with their mojo, and you’ll be playing the weight gain or loss lottery, Source.
Heartbeat harmony
They even have a hand in regulating your heart’s rhythm, ensuring it beats to the right tune, Source.
Cognitive function
They are essential for maintaining brain development and function. It ensures that the gears in your brain are greased up and running smoothly, aiding in memory, focus and mental clarity. No wonder they’re your brain’s best friends, Source.
Bone Braking Bone Health
They regulate bone turnover and mineralization, keeping your skeleton in tip-top shape, Source.
Digestive Dance
Impacts the gastrointestinal function influencing how your digestive system operates. This can effect things like nutrient absorption and overall gut health. Source.
Healthy skin
They even help keep your skin hydrated, ensuring you don’t turn into a scaly lizard.
Oxygen Utilization
They make sure your body uses oxygen efficiently, because who has time for inefficient oxygen use?
Muscle Function
T3 and T4 team up to keep your muscles in tip-top condition. Flex on!
Hyperthyroidism
Also known as Graves disease, which is an autoimmune disease which causes more autoantibodies to stimulate the thyroid stimulating hormone receptor. Resulting in uncontrolled secretion of excessive thyroid hormone, Source. This condition is chronic and typically runs in the family. There are several environmental factors which could cause this condition such as pregnancy, iodine excess, infections, emotional stress and smoking , Source.
Common symptoms are;
- Feeling hot
- Increased sweating
- Muscle weakness
- Trembling hands
- Rapid heartbeat
- Tiredness/fatigue
- Weight loss
- Diarrhea
- Irritability and anxiety
- Eye discomfort and irritation
- Menstrual irregularities
- Infertility
Hypothyroidism
When the thyroid gland doesn’t make enough thyroid hormone, underactive thyroid. There are many causes for this issues such as iodine deficiency which is associated with the autoimmune disease called Hashimotos disease, people often have hypothyroid after surgery or therapy for hyperthyroid such as neck surgery or radioiodine therapy, worryingly about 15% of people treated for Graves’ disease with Carbimazole or Propylthiouracil will develop hypothyroid 10-20 years later, Source.
Common symptoms are;
- Tiredness
- Sensitivity to cold
- Constipation
- Dry skin
- Weight gain
- Puffy face
- Hoarse voice
- Coarse hair and skin
- Muscle weakness
- Muscle aches
Sex hormones
Meet the hormone superstars: Sex Hormone Binding Globulin (SHBG), Total Testosterone, Total Estrogen, and the Free Androgen Index.
Sex hormone binding globulin (SHBG): SHGB binds to androgens (mostly testosterone) and estrogens in order to transport via the blood. Its job is basically to control these hormones in the blood and determine which tissues these hormones can get access to, Source.
Total testosterone: This is the total amount of testosterone in the bloodstream. This is determined by both free testosterone which is the testosterone not attached to anything and bound testosterone, which is the testosterone attached to other stuff such as SHBG.
Total estrogen: Like total testosterone is the amount of estrogen in your blood, both free and bound.
Free androgen index: This is a ratio usually figured out after a blood test for testosterone. Free androgen index (FAI) = Total Testosterone/SHBG x 100 %, Source.
The science
Hypothyroidism and hyperthyroidism are associated with sex hormone concentrations. This study from 2021 did a comprehensive analysis of the data, looking at hyperthyroid and hypothyroid effects on sex hormones in both men and woman.
So, why all the hype about thyroid hormones and sex hormones? Well, increased thyroid hormone increases the hepatic metabolism and hepatocyte nuclear factor concentrations. This stimulates the SHBG promoter to increase SHBG transcription, and consequently results in increased SHBG concentrations.
SHBG inhibits testosterone and Estrogen by binding to them and thereby decreasing their bioavailability. So, when T4 increases, SHBG concentrations increases and consequently further down the pathway the total testosterone and estradiol concentrations increase in order to maintain an appropriate bioavailability to these hormones.
Therefore, thyroid hormones regulate bioavailability of sex hormones by increasing the concentrations of hepatic nuclear factor, which increases SHBG. Well, generally speaking if SHBG is higher we should expect to see less testosterone and estrogen and if it’s lower we should expect to see higher testosterone and estrogen.
What does this all mean?
Hypothyroid
The study shows that hypothyroid was associated with decreased SHBG and decreased total testosterone. However the association was more evident in woman than in men. In men the results were inconsistent showing a possible casual association but not supported by the main analysis. Furthermore men with hypothyroidism showed no associations with any change in testosterone concentrations.
Hypothyroidism was associated with decreased free androgen index [FAI] in woman and increased FAI in men. This does not mean that men will have more testosterone in your body. As there is a decrease in SHBG, with testosterone staying the same, this will increase the FAI. However, this does mean that men will have more testosterone available for your body to use.
Hyperthyroidism
Inversely hyperthyroidism was associated with increased SHBG concentrations in men only. In addition Hyperthyroidism was associated with increased testosterone in woman only. Due to this Hyperthyroidism was associated with decreased FAI in men and increased FAI in woman.
T4 was associated with increased concentrations of testosterone in woman only. This Suggests that T4 may influence concentrations of testosterone and estrogen through other pathways than SHBG in woman. This resulted in females with Hyperthyroidism having increased availability of testosterone but males having decreased availability
Conclusion
The study answers the question, does hypothryoidism increase testosterone? Hypothyroidism increases free testosterone available for your body to use, only if you are male. If your female then testosterone decreases along with SHBG.
So will this help with the gains? Possibly if you’re male, however, with hypothyroidism you will also be dealing with fatigue, muscle aches, muscle pains, cognitive function and possible more. So its probably better to get the condition sorted and actually be able to go to the gym. But in theory you will have an increase in testosterone.
Unfortunately for men hyperthyroidism you will be dealing with similar symptoms but also have a reduced amount of testosterone available. Inversely females will have increased testosterone, but again will have to deal with all those symptoms.
So females will have increased testosterone with hyperthyroid and males increased testosterone with hypothyroid. But should you try and take advantage of the impact on sex hormones from your auto immune disease? Definitely not, as someone who has experienced hypo and hyper thyroid the longer you stay in one of these states the longer it takes to get out and the worse the symptoms will be. If you do have one of these conditions and you are looking to build muscle, I have been there and can help you. Either send a message on the contact form, or have a read of my steps to build muscle with hyperthyroid and supplements to take for hypo or hyper thyroid.