Ray Peat on Adrenaline

November 29, 2025

Adrenal response to inflammation and stress hormones

"When the body detects inflammation or other stress (possibly by sensing changes in blood sugar, lactic acid, or carbon dioxide—or all together), its adrenal glands will release anti-stress hormones, including adrenaline and cortisone (provided these glands are not exhausted or undernourished). Both adrenaline and cortisone can raise blood sugar levels to meet the increased demand."

– Nutrition for Women

Blood sugar as an integrating factor for stress

"From my own experience, I tend to believe that blood sugar is an important integrating factor and that the body can probably perceive small or rapid fluctuations that are very difficult to detect with usual lab methods. For example, it is known that especially men release adrenaline under the stress of having blood drawn, which tends to increase blood sugar concentration."

– Nutrition for Women

Metabolic effects of caffeine and adrenaline on sugar and fat utilization

"Since both caffeine and adrenaline increase metabolic rate, fat is likely consumed faster. It is known that adrenaline raises blood sugar, apparently by inhibiting glucose use and increasing fat use. Coffee usually raises blood sugar through its adrenaline-like effect."

– Nutrition for Women

Effects of coffee and adrenaline on glycogen depletion during fasting

"During fasting, coffee and/or adrenaline can accelerate the depletion of glycogen stores and thereby trigger the onset of hypoglycemia more quickly."

– Nutrition for Women

The influence of vitamin C on tyrosine metabolism and adrenaline levels in tissues

"Tyrosine metabolism, which is involved in brain function, is sensitive to vitamin C. Additionally, vitamin C maintains adrenaline levels in tissues—possibly by inhibiting its oxidation—and adrenaline is necessary for chalones to perform their function, namely to inhibit cell division."

– Nutrition for Women

Salty snacks and improving sleep quality

"Salty snacks are especially helpful in making it easier to fall asleep, presumably by stabilizing blood sugar and lowering adrenaline. Ice cream, which combines sugar, calcium, and some fat that delays sugar absorption, is often effective in improving sleep quality."

– March 2018 – Ray Peat’s Newsletter

The effects of hypothyroidism on skin and adrenaline production

"Many people with hypothyroidism compensate for this through high adrenaline production (sometimes up to 40 times higher than normal), which causes the skin to remain cool, especially on the hands, feet, and nose. The high adrenaline is a result of low blood sugar, so consuming carbohydrates, like a glass of orange juice, can sometimes temporarily lower the heart rate."

– Generative energy: Restoring the wholeness of life

The role of adrenaline in depression, stress, and inflammation

"Increased adrenaline – similar to elevated cortisol levels – is a feature of depression, stress, and inflammation; by mobilizing fats, it can become part of a vicious cycle in which free fatty acids cause insulin resistance and thereby activate stress responses."

– February 2001

The unique receptor behavior and tissue interaction of estrogen

"The effect of estrogen on many tissues increases the tissue's ability to bind estrogen; estrogen thus stimulates the formation of its own receptors – in a self-stimulating and at the same time self-destabilizing process. This differs from the behavior of other receptors, such as the adrenaline receptor, which is inactivated by increased adrenaline exposure. This unusual interaction between tissue and hormone requires careful investigation."

– March 2000

Hypothyroidism and excessive activity of the adrenergic nervous system

"In hypothyroidism, the adrenergic nervous system tends to be overactive, and adrenaline production remains high even when there is no external reason for it, because adrenaline is needed to maintain adequate blood sugar levels and enough energy in the inefficient metabolic state of hypothyroidism."

– January 2000 – Ray Peat’s Newsletter

The role of estrogen in mobilizing free fatty acids and edema

"Adrenaline mobilizes free fatty acids from tissues, including fat and muscle tissue. Estrogen itself leads to increased free fatty acids. When the free fatty acids are unsaturated, they cause edema by making blood vessels permeable."

– January 2000 – Ray Peat’s Newsletter

The role of the thyroid in sleep and energy production

"Since I had become a deep sleeper as soon as I started taking thyroid, and had seen that thyroid alone could cure most people's insomnia (sometimes, as a doctor described his experience, even better than morphine), I began to understand that the adrenaline disrupting sleep was a sign of faulty energy production, and that the things restoring sleep – for example thyroid, salt, sugar, protein, and progesterone – acted directly on the cells' energy production."

– January 2000 – Ray Peat’s Newsletter

Salt and thyroid effects on blood pressure and sleep

"Since increased adrenaline tends to raise blood pressure, I began explaining to friends over 80 the effects of salt and thyroid. They found that they slept better, had more regular heartbeats, and did not get swollen feet when they consumed a normal amount of salt. Their blood pressure did not increase as a result."

– January 2000 – Ray Peat’s Newsletter

Salty foods before bedtime to improve sleep

"I have recommended salty foods before bedtime to promote sleep because of the well-known anti-adrenaline effect of sodium. There are some complicated thoughts about its effect on adrenaline, as well as explanations for its thermogenic effect, but the simple fact that sodium is needed for glucose uptake can explain its ability to lower adrenaline (since adrenaline rises when glucose is needed) and increase heat production."

1998 – Ray Peat’s Newsletter – Issue 4

The importance of thyroid hormones for sustained brain energy

"Thyroid hormones are crucial for providing the brain with a sustained high energy level. When these hormones are lacking, our nerves need stimulants to function normally, and our body usually produces large amounts of adrenaline to keep us going. The result is that we feel both tired and tense at the same time."

April 1994 – Ray Peat’s Newsletter

Influence of carbohydrates and salt on brain energy and relaxation

"The brain is like a muscle and must restore its energy to relax. Many people have noticed that they become tired after consuming a lot of carbohydrates and/or salt. Both salt and carbohydrates tend to lower adrenaline, and carbohydrates can also increase thyroid hormone activity while restoring tissue energy."

April 1994 – Ray Peat’s Newsletter

Effects of stress on glucose and fat utilization

"When tissues are not sufficiently supplied with oxygen, glucose is quickly consumed. During prolonged stress, the liver's gluconeogenic response to glucocorticoids and its ability to form and store glycogen are reduced. As glucose becomes less available, the amount of adrenaline in the blood increases, and fat is mobilized from stores as an alternative energy source. Free fatty acids, especially unsaturated fats, are toxic to the mitochondrial respiratory system because they block both the ability to use oxygen and energy production. The increased use of fats instead of glucose leads to a rise in lipid peroxidation."