Korean Angelica (Angelica gigas), known as "Dang Gui" in traditional Korean and Chinese medicine, has a long-standing history of use as a tonic herb. Traditionally, it is believed to nourish and invigorate the blood, and support overall vitality and energy, particularly in situations of fatigue or weakness. Historical texts and medical compendiums from East Asia describe its usage in formulas intended to "tonify Qi" (vital energy) and improve stamina, especially among women and the elderly. The root of Korean Angelica is often included in multi-herb preparations aimed at addressing tiredness, weakness, and convalescence after illness.

However, scientific validation for these energy-boosting effects is limited. Some animal studies suggest possible anti-fatigue, neuroprotective, or adaptogenic properties, but robust clinical trials in humans are lacking. Most of the evidence supporting the use of Korean Angelica for improving energy remains anecdotal or based on traditional practice rather than modern scientific research. Therefore, the justification for its use to support energy is primarily traditional, with a moderate level of traditional evidence but insufficient scientific confirmation.