Test Your Thyroid Function

The production of T3 is further compromised by physical or mental stress, as stress hormones (cortisol and adrenaline) directly interfere with the T4 to T3 conversion process (Peat, 2008, p. 3).

Therefore, measuring the concentration of rT3 becomes meaningful (Ray Peat Clips, 2016a). A normal level is considered to be between 8-24 ng/dL (Mary Shomon, 2022). However, many thyroid specialists suggest that an optimal rT3 level should be at the lower end of this range. (Stop the thyroid Madness, 2023).

cabbage, broccoli, cauliflower, Brussels sprouts, and kale —

A balanced breakfast could feature butter-fried eggs, generously seasoned with salt, accompanied by carbohydrate-rich fruits such as orange juice. Alternatively, one could opt for salty cheese or Greek yogurt paired with fruit. Including salt in a balanced breakfast, such as adding a pinch of salt to your orange juice, can be beneficial, as salt is

Focusing on pre- and post-meal measurements can help distinguish the effects of thyroid function from stress, as cortisol and adrenaline levels normally come down after a meal.

After consuming a balanced breakfast cortisol and adrenaline levels typically begin to normalize as blood sugar is sustained by food, instead of the stress hormones. This is an opportune time to measure both temperature and pulse rate, as it offers a clearer indication of thyroid function, free from the distortive effects of stress hormones (Peat,

Typically, adrenaline and cortisol levels begin to rise after a person goes to bed. For those with hypothyroidism, these levels can spike sharply, with adrenaline peaking around 1 or 2 A.M., and cortisol around dawn (Peat, 2008, p. 5). It's not uncommon for people to wake up with a pounding heart during the adrenaline surge (Peat, 2008, p. 5).

He noted that healthy individuals with good thyroid function usually have an average resting pulse rate of about 85 beats per minute, whereas those in less-than-optimal health often have rates around 70 beats per minute (Peat, 2008, p. 4).

The body is known to ramp up the production of rT3 during crisis situations such as critical illness, extreme dieting, or starvation (Mary Shomon, 2022; Alan Jacobs, 2023). Stress, and specifically the stress hormones adrenaline and cortisol, can increase the production of rT3 (Peat, 2008, p. 3; Ray Peat Clips, 2016a).