Under 21 CFR 101.93(f), supplement labels may describe how ingredients affect the body's energy-producing systems — specifically, the metabolic processes that convert nutrients into ATP and support cellular energy production. These are structure/function claims about normal physiological energy metabolism.
The compliance challenge: the way brands write energy claims often goes well beyond energy metabolism into outcome territory that implies the product will treat fatigue, tiredness, or energy disorders — all of which are disease-adjacent states under FDA's framework.
Permitted Energy Structure/Function Claims
"Supports healthy energy levels"
"Promotes energy metabolism"
"Supports the body's natural energy production"
"Helps convert food into energy"
"Supports healthy mitochondrial function"
"Promotes cellular energy production"
"Helps maintain energy throughout the day"
These describe support for normal metabolic energy function in healthy individuals. They're substantiated by evidence for how specific ingredients participate in energy-producing biochemical pathways.
Where Energy Claims Cross Into Prohibited Territory
Prohibited or high-risk energy claims:
"Cures fatigue" — fatigue is a symptom of numerous diseases; treatment claims are prohibited
"Eliminates tiredness" — treatment of a symptom associated with disease
"For people with chronic fatigue" — references a medical condition (Chronic Fatigue Syndrome)
"Restores energy lost to illness" — treatment of illness-related energy depletion
"Clinically proven to triple your energy" — specific quantified outcome claims require FTC-standard evidence
"Gives you superhuman energy" — superlative outcome claim
"Combats energy crashes from blood sugar spikes" — blood sugar spikes are associated with diabetes and metabolic disease
The fatigue problem
"Reduces fatigue" exists in a gray zone. In FDA warning letters, the agency has treated claims about reducing fatigue as structure/function claims when they describe normal exercise-related fatigue in healthy individuals. The same claim applied to people experiencing fatigue from illness, chronic conditions, or medical treatment is a disease claim.
Context matters enormously. "Reduces exercise-induced fatigue" may be permissible when the product is a sports supplement used by healthy athletes. The same claim on a general wellness product marketed to broad audiences may be read as implying treatment of pathological fatigue.
Caffeine: High Evidence, Still Needs Careful Framing
Caffeine has well-established acute effects on alertness and energy. But caffeine's regulatory classification is more complex than its marketing suggests:
At typical doses in supplements (less than 200mg per serving), caffeine is generally recognized as safe as a food ingredient. At higher doses, or when marketed with claims about its effects on specific conditions, its regulatory status becomes more complex.
Energy claims for caffeine-containing supplements should describe its role in supporting alertness and normal energy function — not imply that it treats energy disorders or that it produces guaranteed performance outcomes beyond what the evidence supports.
B Vitamins and Energy Claims
B vitamins — particularly B12, B6, riboflavin, niacin, and pantothenic acid — play documented roles in energy metabolism. The FDA has accepted structure/function claims for these vitamins related to energy metabolism based on their roles as cofactors in ATP-producing biochemical pathways.
However, the clinical evidence for B vitamin supplementation increasing subjective energy in people who are not deficient is limited. A claim that your B12 supplement "boosts energy" for a general population assumes that the supplement increases energy beyond baseline — which requires evidence that supplementation at your dose produces that effect in non-deficient individuals.
If the evidence primarily shows benefits in deficient populations, general energy claims for non-deficient adults may overstate what the science supports under the FTC's competent and reliable scientific evidence standard.
Adaptogen Energy Claims
Adaptogens (ashwagandha, rhodiola, ginseng, cordyceps) are commonly used in energy and stress-support products. Their regulatory framing requires the same care as other supplement categories:
"Supports energy and vitality" is a structure/function claim. "Treats adrenal fatigue" is a disease claim — and "adrenal fatigue" is a contested medical concept that the FDA would view as referencing a disease state. Products specifically marketed for adrenal fatigue face compound risk: disease claim exposure plus potential FTC scrutiny for claims based on a scientifically contested condition.
Energy is one of the most popular claims and one of the easiest to overreach
Truli scans energy claims against 21 CFR 101.93's structure/function framework and flags language that crosses into fatigue treatment, disease-adjacent territory, or unsubstantiated quantified outcomes. In a category where "boost," "maximize," and "optimize" are the default vocabulary, a compliance scan before you finalize copy is the lowest-cost risk management step available.
A note from Truli: Truli is not a law firm, and this article does not constitute or contain legal advice or create an attorney-client relationship. When determining your obligations and compliance with respect to relevant laws and regulations, you should consult a licensed attorney.
