Rhodiola rosea is commonly used as an adaptogen, a substance believed to help the body resist physical, chemical, and biological stressors. Its use for "adrenal support" largely stems from the theory that adaptogens can enhance the body's resilience to stress and balance the hypothalamic-pituitary-adrenal (HPA) axis, although the term "adrenal support" is not a recognized medical diagnosis.

There is some scientific research to back the adaptogenic properties of rhodiola. Several human clinical trials have found that rhodiola supplementation may improve symptoms of stress, fatigue, and mental performance. For example, a systematic review in Phytomedicine (2011) concluded that rhodiola may have beneficial effects on physical performance and mental fatigue under stressful conditions. However, most studies are short-term, involve small sample sizes, and often lack rigorous methodology.

While these studies suggest rhodiola can mitigate stress-related fatigue, direct evidence that it specifically "supports the adrenal glands" in a clinical sense is limited. The rationale for its use is therefore based more on its general stress-modulating effects than on direct effects on adrenal gland structure or function. More robust and specific clinical trials are needed to confirm its efficacy for adrenal health.