The only two times I have experimented with thyroid in the past several months, I end up catching a flu virus. I think it is well-explained by my theory.
My theory is that thyroid, although it may boost the metabolism and the activity of the immune system itself, it increases cortisol as a result of the heightened metabolism, and so, the body's "cracks" open up with this stress, allowing the intruders in. So it is probably better to leave the cracks closed and not take thyroid, and instead take serotonin, histamine, and estrogen antagonists, keep warm, etc when there is a high chance of infection.
In other words, take thyroid when there is no sick people around because it will increase your susceptibility for infection.
Serotonin, histamine, and estrogen antagonists boost thyroid too by reducing stress. But if there is a stressor like an infection, they won't or they will do it less, for very good reason. The fact that reducing these "bad guy chemicals" often increases thyroid function is the main argument against thyroid supplementation.
I know that I won't take thyroid again until my stress level is super-low. I don't want to get infected again (I got infected twice in a row this time with two different viruses). Obviously taking thyroid while one is sick is a terrible idea too. Another drawback is that the CO2 increase increases chances that the infection will spread deeper into your body.
So putting my warning here.
My theory is that thyroid, although it may boost the metabolism and the activity of the immune system itself, it increases cortisol as a result of the heightened metabolism, and so, the body's "cracks" open up with this stress, allowing the intruders in. So it is probably better to leave the cracks closed and not take thyroid, and instead take serotonin, histamine, and estrogen antagonists, keep warm, etc when there is a high chance of infection.
In other words, take thyroid when there is no sick people around because it will increase your susceptibility for infection.
Serotonin, histamine, and estrogen antagonists boost thyroid too by reducing stress. But if there is a stressor like an infection, they won't or they will do it less, for very good reason. The fact that reducing these "bad guy chemicals" often increases thyroid function is the main argument against thyroid supplementation.
I know that I won't take thyroid again until my stress level is super-low. I don't want to get infected again (I got infected twice in a row this time with two different viruses). Obviously taking thyroid while one is sick is a terrible idea too. Another drawback is that the CO2 increase increases chances that the infection will spread deeper into your body.
So putting my warning here.