Adrenal cortex
Synopsis
The adrenal cortex is the outer layer of the adrenal glands, which sit atop the kidneys and are essential for the production of several vital hormones. It accounts for approximately 80–90% of the adrenal gland’s total mass and is divided into three distinct zones—zona glomerulosa, zona fasciculata, and zona reticularis—each responsible for synthesizing different classes of steroid hormones. These include mineralocorticoids (like aldosterone), glucocorticoids (primarily cortisol), and androgens (such as DHEA).
The adrenal cortex plays a central role in regulating metabolism, immune response, fluid and electrolyte balance, stress adaptation, and sexual development. Aldosterone helps maintain blood pressure and sodium-potassium balance by signaling the kidneys to retain sodium and excrete potassium. Cortisol, the most prominent glucocorticoid, helps regulate blood sugar, inflammation, and the body’s response to stress. DHEA, a weak androgen, serves as a precursor to sex hormones and is involved in mood, libido, and energy levels.
In integrative and functional medicine, the adrenal cortex is frequently discussed in the context of adrenal fatigue or adrenal insufficiency, especially in individuals experiencing chronic stress, burnout, or hormonal imbalance. While “adrenal fatigue” is not a formally recognized diagnosis in conventional medicine, many practitioners use the term to describe symptoms associated with dysregulated cortisol production, including fatigue, irritability, poor sleep, and low resilience to stress.
Extracts of adrenal cortex tissue, usually from bovine sources, are used in glandular therapy, a practice dating back to the early 20th century. These supplements aim to provide nutritional support for the adrenal glands, supplying naturally occurring peptides, enzymes, and cofactors that may help restore optimal adrenal function. They are often combined with adaptogenic herbs and nutrients such as vitamin C, B vitamins, ashwagandha, and rhodiola in adrenal support formulas.
Historical Use:
The adrenal glands and their hormones were not explicitly recognized in ancient medicine, but their functions—particularly stress adaptation, energy maintenance, and salt regulation—were addressed through broader constitutional and energetic models. In Traditional Chinese Medicine (TCM), adrenal function is closely aligned with the Kidney system, which governs vitality, willpower, and longevity. TCM herbs like cordyceps, rehmannia, and eucommia were traditionally used to tonify Kidney Qi and Jing (essence), addressing what we now understand as adrenal-related fatigue or hormonal decline.
Similarly, in Ayurveda, the adrenal role is conceptually linked to ojas (vital essence) and agni (metabolic fire). Chronic stress and overstimulation were believed to deplete ojas, leading to symptoms of exhaustion, weakened immunity, and poor stress response. Rejuvenative tonics like ashwagandha, shatavari, and licorice were commonly used to rebuild strength and endurance, which parallels the modern approach to adrenal support.
Although the adrenal cortex was scientifically described only in the 19th century, and its hormones isolated and synthesized in the 20th century, its role in maintaining energy, balance, and resilience has long been addressed through traditional herbal strategies. Today, adrenal cortex supplements represent a modern biochemical tool rooted in time-honored goals: restoring vitality, improving stress tolerance, and supporting hormonal harmony.
Body Systems
Adrenal Cortex (Science)
Adrenal Glands (Science)
Adrenal Medulla (Traditional)
Glandular System (Science)