Best Supplements for Energy That Aren't Just Caffeine

Suppi Research Team · February 28, 2026 · 10 min read

Most "energy supplements" are just caffeine in a fancy wrapper. Green tea extract, guarana, yerba mate—these are all caffeine sources. There's nothing wrong with caffeine, but if that's all you want, a cup of coffee is cheaper and more honest about what it is.

The more interesting question is: what actually helps with fatigue beyond stimulants? That depends entirely on why you're tired. Nutrient deficiencies, poor mitochondrial function, chronic stress, and inadequate sleep all cause fatigue through different pathways. Different supplements address different causes.

Here's what the evidence supports.

1. Vitamin B12 — But Only If You're Deficient

B12 is involved in red blood cell production and neurological function. When you're deficient, fatigue is one of the first symptoms—your cells literally can't produce energy efficiently because B12 is a cofactor in mitochondrial metabolism.

Who's at risk of deficiency:

• Vegans and vegetarians — B12 is found almost exclusively in animal products. Without supplementation, deficiency is essentially inevitable over time.
• Adults over 50 — Stomach acid production declines with age, reducing B12 absorption from food.
• People on metformin — This common diabetes medication reduces B12 absorption. Studies show 10-30% of metformin users develop deficiency.
• People with GI conditions — Crohn's, celiac, or any condition affecting the ileum (where B12 is absorbed).

Here's the thing: if your B12 levels are normal, supplementing more won't give you extra energy. Your body doesn't work that way. You can't supercharge a full tank. Those B12 energy shots at the gas station counter? They work for deficient people. For everyone else, it's placebo plus whatever caffeine they added.

Dosage: 500-1000mcg of methylcobalamin or cyanocobalamin daily for maintenance. If deficient, your doctor may start with injections or higher oral doses (1000-2000mcg).

Testing: Ask for serum B12 and methylmalonic acid (MMA). MMA is a more sensitive marker—B12 can appear "normal" on a standard test while you're functionally deficient.

2. Iron — Critical Warning: Test First

Iron deficiency is the most common nutritional deficiency worldwide, affecting roughly 1.6 billion people. It's also the most common cause of anemia. Fatigue from iron deficiency isn't subtle—it's crushing.

But here's why iron is different from every other supplement on this list: you should never supplement iron without a blood test confirming deficiency.

Excess iron doesn't get excreted like excess vitamin C or B vitamins. It accumulates. Iron overload (hemochromatosis) damages the liver, heart, and pancreas. About 1 in 200 people of Northern European descent carry the genetic mutation for hereditary hemochromatosis. Blindly supplementing iron in these people is genuinely dangerous.

Groups at higher risk of iron deficiency:

• Menstruating women — Monthly blood loss depletes iron. About 20% of women of childbearing age have low ferritin.
• Endurance athletes — Foot-strike hemolysis, GI bleeding from high-intensity exercise, and increased hepcidin levels can all reduce iron.
• Vegetarians and vegans — Plant-based (non-heme) iron is absorbed at about 2-5% vs 15-35% for animal-based (heme) iron.
• Frequent blood donors

Testing: Get ferritin levels checked. Optimal is generally 40-100 ng/mL. Below 30 is associated with fatigue even without frank anemia. Below 12 indicates depleted stores.

Dosage (if deficient): 18-65mg of elemental iron daily, taken with vitamin C (which increases absorption by 2-3x). Take on an empty stomach if tolerated. Iron bisglycinate causes fewer GI side effects than ferrous sulfate.

A 2012 study in the Canadian Medical Association Journal found that iron supplementation significantly reduced fatigue in non-anemic women with low ferritin levels. The effect is real, but only when there's an actual deficit to correct.

3. CoQ10 (Coenzyme Q10) — Mitochondrial Support

CoQ10 sits in your mitochondria and is directly involved in producing ATP—your body's energy currency. Every cell needs it. Your body makes it naturally, but production declines with age. Statin medications also reduce CoQ10 levels (they inhibit the same pathway your body uses to produce it).

A 2014 systematic review in the Journal of Clinical Pharmacy and Therapeutics found that CoQ10 supplementation reduced fatigue symptoms across several conditions, including chronic fatigue syndrome and fibromyalgia. A 2008 randomized trial showed that 300mg/day of CoQ10 significantly reduced physical fatigue in healthy volunteers during a cycle ergometer test.

The evidence is particularly strong for statin users. A 2018 meta-analysis of 12 RCTs found that CoQ10 reduced statin-associated muscle symptoms in about 75% of cases, which often includes the fatigue and weakness that makes some people quit their statins.

Dosage: 100-200mg daily for general energy. 200-300mg for statin users. Take with a meal containing fat (CoQ10 is fat-soluble). The ubiquinol form has better absorption than ubiquinone, especially in people over 40.

4. Creatine — Not Just for the Gym

Most people associate creatine with bicep curls and protein shakes. But creatine's role in energy production is fundamental—it regenerates ATP, the molecule every cell uses for energy. Your brain, which uses about 20% of your total energy, is particularly responsive to creatine.

A 2018 meta-analysis in Experimental Gerontology found that creatine supplementation improved both physical and cognitive performance in older adults. A 2002 study in the Proceedings of the Royal Society showed that creatine supplementation improved working memory and processing speed, particularly under conditions of sleep deprivation or mental fatigue.

A 2017 systematic review of six studies found that creatine reduced mental fatigue during demanding cognitive tasks. The effects are modest but consistent.

If you're vegetarian or vegan, the effect may be more pronounced—dietary creatine comes exclusively from meat and fish, so plant-based eaters have lower baseline levels.

Dosage: 3-5g of creatine monohydrate daily. No loading phase needed. No cycling needed. Read our full creatine safety breakdown.

5. Rhodiola Rosea — The Adaptogen With Actual Data

The word "adaptogen" gets thrown around so loosely that it's almost meaningless at this point. But rhodiola rosea has more clinical trial data behind it than most herbs in its category.

A 2012 review in BMC Complementary and Alternative Medicine analyzed 11 studies and found that rhodiola demonstrated consistent anti-fatigue effects, particularly for physical fatigue and stress-related mental exhaustion. One standout: a 2000 study of physicians on night duty found that 170mg of rhodiola extract significantly reduced fatigue-related impairment compared to placebo.

A 2009 phase III clinical trial gave 101 subjects experiencing life-stress symptoms either 200mg of rhodiola extract (SHR-5) twice daily or placebo. After 4 weeks, the rhodiola group showed significant improvements in fatigue, exhaustion, and stress resilience starting from day 3 of treatment.

Rhodiola appears to work by modulating cortisol and activating AMPK (an enzyme involved in cellular energy sensing). Unlike caffeine, it doesn't spike and crash. Effects build over days to weeks.

Dosage: 200-400mg of standardized extract (3% rosavins, 1% salidroside). Take in the morning or early afternoon—it can be mildly stimulating and may interfere with sleep if taken late.

6. Ashwagandha — Energy Through Stress Reduction

Ashwagandha doesn't boost energy directly. It reduces the fatigue caused by chronic stress. If your tiredness stems from being cortisol-fried—poor sleep, feeling wired but exhausted, afternoon crashes—ashwagandha addresses the root cause rather than masking it.

A 2012 study by Chandrasekhar et al. gave 64 chronically stressed adults either 300mg of KSM-66 ashwagandha extract twice daily or placebo for 60 days. The ashwagandha group had 28% lower cortisol levels and significant improvements in stress scores and overall well-being.

For exercise-related energy, a 2015 study found that 600mg/day of ashwagandha root extract increased VO2max, improved endurance, and enhanced self-reported energy in healthy athletic adults after 12 weeks.

Dosage: 300-600mg of KSM-66 or Sensoril extract daily. For more, see our full ashwagandha guide.

What to Avoid

Proprietary energy blends

If a label says "Proprietary Energy Matrix: 500mg" and lists 8 ingredients without individual amounts, run. This means the doses are almost certainly too low to work. The company is betting that you'll recognize the ingredient names and not notice that each one is present at 1/10th the effective dose.

Mega-dose B vitamins

Products with 5,000% or 10,000% of the daily value for B6 or B12 aren't giving you extra energy. Your body can only use so much. Water-soluble B vitamins are excreted in urine when you exceed your body's capacity. High-dose B6 (over 100mg/day long-term) can actually cause peripheral neuropathy—nerve damage in your hands and feet.

Products that are secretly just caffeine

Green coffee bean extract, guarana, kola nut, green tea extract at high doses—these are all caffeine delivery systems. There's nothing wrong with caffeine, but be aware of what you're actually taking, especially if you're combining with coffee.

Quick Reference Table

The best "energy supplement" for most people is fixing their sleep, hydration, and blood work. Supplements work at the margins. If your basics are broken, no pill will compensate. — Suppi Research Team