Lavender (Lavandula angustifolia) has a long history of use in traditional herbal medicine, primarily for its calming, sedative, and anxiolytic properties. Its use to support or "treat" adrenal fatigue is not grounded in robust scientific research but rather in traditional and integrative medicine practices. "Adrenal fatigue" itself is a controversial and unrecognized diagnosis in conventional medicine; it is not acknowledged as a legitimate medical condition by most endocrinologists or major medical organizations. However, proponents of alternative medicine often associate adrenal fatigue with chronic stress and symptoms such as fatigue, sleep disturbances, and anxiety.

Lavender is commonly used in aromatherapy and herbal preparations to promote relaxation and reduce stress. Some small clinical studies have shown that lavender essential oil, when inhaled or taken orally in specific preparations, can reduce anxiety and improve sleep quality. These effects are thought to indirectly support "adrenal health" by mitigating the impact of chronic stress, which is believed by some practitioners to play a role in adrenal fatigue. However, there is no direct scientific evidence that lavender can treat or repair adrenal glands or alter cortisol production.

In summary, the use of lavender for adrenal fatigue is primarily based on its traditional reputation for reducing stress and anxiety, rather than scientific proof of direct adrenal effects. Thus, while lavender may be helpful for stress-related symptoms, its role in "adrenal fatigue" should be regarded as traditional and the evidence supporting direct benefits is weak.