This site names Rhodiola Rosea specifically as an adaptogenic root traditionally used to fight mental fatigue — worth understanding this ingredient on its own terms.
Rhodiola Rosea is described as traditionally used to fight mental fatigue, build resilience and support steady mental energy — positioned as the formula's fatigue-focused ingredient, distinct from B12's energy role.
Worth distinguishing B12's nervous-system-and-energy role from Rhodiola's fatigue-and-resilience role — this site treats them as complementary, not redundant, ingredients within the formula's five mechanism fronts.