Kelp, a type of seaweed, has been traditionally used as a dietary supplement primarily due to its high iodine content, which is essential for healthy thyroid function. The thyroid and adrenal glands are both part of the endocrine system and interact in regulating metabolism, energy, and stress responses. In traditional health practices, especially in herbalism and naturopathy, kelp is sometimes recommended to support "adrenal health" because optimal thyroid function is thought to indirectly support overall endocrine balance, including the adrenals. However, there is minimal direct historical emphasis on kelp specifically for adrenal gland support, as most references focus on its thyroid benefits.

Scientifically, there is little to no direct evidence that kelp supplementation directly supports adrenal gland function. Most research and clinical evidence surrounding kelp revolves around its iodine content and its effects on thyroid hormone production. There are no significant clinical trials or mechanistic studies demonstrating a benefit of kelp for adrenal health specifically. Thus, while its use for adrenal support is rooted in traditional or holistic paradigms, this practice is not well-supported by direct scientific evidence.