The adrenal gland, an endocrine gland situated near the kidneys, is divided into two parts. The inner portion (medulla) of the adrenal gland secretes epinephrine (adrenaline) and norepinephrine (adrenaline). The outer portion (the cortex) manufactures the hormones cortisone and aldosterone. All these hormones are necessary for life.

Adrenal extracts are made from the adrenal glands of cows, pigs, or other animals. According to a theory prevalent in alternative medicine, the consumption of adrenal extracts can strengthen the function of an underperforming or exhausted adrenal gland. However, there is no scientific evidence to support this belief, and no rational justification to indicate that it might be true.

Early in the twentieth century, physicians used glandular extracts as an actual source of hormones. For example, extracts of ovaries were used to supply female hormones such as progesterone. Similarly, animal adrenal glands may contain significant levels of adrenal hormones. This is the basis for some of the recommended uses of adrenal extracts, such as allergies , asthma , and rheumatoid arthritis (conditions that respond to cortisone). However, modern adrenal extracts are manufactured in such a way that they do not contain significant levels of adrenal hormones. Therefore, it is difficult to find any justification for their use along these lines.

Some manufacturers of glandular products claim that the animal version of an organ provides nutrients that support the corresponding organ in humans. However, there is no evidence that the human adrenal gland requires any nutrients that are uniquely available in animal adrenals.

It has been suggested by one manufacturer of glandular products that consuming extracts of an organ might offer benefit in an immune-related manner. According to this theory, some people may possess antibodies to certain of their own glands, and the consumption of an animal version of the gland will divert these antibodies from their target. However, this explanation does not make a great deal of sense. Antibodies are primarily produced against proteins, and even if cow adrenal glands had the same proteins as human adrenal glands, which is unlikely, proteins are not absorbed whole into the bloodstream.

It may be that, on an unconscious level, those who recommend glandular extracts are being influenced by the ancient notion of “sympathetic magic,” the idea that eating a lion’s heart, for example, will create courage. However, this is a pre-scientific form of thinking that is difficult to take seriously in the modern era.

Not only is the proposed action of adrenal glandular extracts questionable, their primary proposed purpose for use is questionable as well. Adrenal glandular extracts are most often recommended for treatment of a purported condition called “adrenal exhaustion.” In adrenal exhaustion, the adrenal glands are supposedly weakened by the chronic stresses of modern life and incapable of performing at full capacity. However, there is no believable scientific basis for believing this to be true. The notion of adrenal exhaustion developed as a result of studies done in the mid-twentieth century that involved extreme, life-threatening stress; the studies do not support the existence of a milder, common “adrenal fatigue.” (And even if it did exist, there is no reason to think that adrenal extracts would help.)

Finally, there are no meaningful scientific studies that have found benefit with adrenal gland extracts in their modern, non-hormonal form. Only double-blind, placebo-controlled studies can show a treatment effective, and at present none have been reported for adrenal extracts. (For information on why this type of study is essential, see Why Does This Database Rely on Double-blind Studies? )