Persistent fatigue gets treated as a supplement problem when it's typically a diagnosis problem. This protocol walks the workup first — thyroid, ferritin, B12, vitamin D, testosterone, sleep apnea, depression screening — then the lifestyle foundation, then the mitochondrial and cellular energy support layer (CoQ10, NAD+ precursors, creatine, PQQ), and finally adaptogens. The honest framing: most chronic fatigue resolves with diagnosis and underlying-condition treatment, not stim stacks.

Evidence and pricing are current as of May 2026; new trials may change the picture.

Why This Protocol Exists

Chronic fatigue is the symptom-of-the-month in optimization culture. Stim stacks, mitochondrial 'boosters', adaptogens, and energy peptides get marketed and stacked together with substantial overlap and limited clarity about what's actually moving outcomes. The reality is more boring and more effective: most chronic fatigue has identifiable underlying drivers — thyroid dysfunction, iron deficiency (substantial even in men), B12 deficiency, vitamin D deficiency, hypogonadism, sleep apnea, depression, sleep deprivation — and resolves when the underlying issue is addressed. A diagnostic-first protocol produces substantially better outcomes than stacking supplements on top of an unrecognized underlying condition.

Step 1 — Workup (Skip at Your Peril)

Persistent fatigue (>2-3 months without clear explanation) warrants formal workup before supplement protocols:

Complete blood count. Anemia is a common and treatable cause of fatigue.

Ferritin. Iron stores marker. Low ferritin (often <30-50 ng/mL depending on lab) can cause fatigue even with normal hemoglobin. Even iron deficiency without overt anemia produces real fatigue. Often overlooked in men ('iron deficiency is a women's issue' is incorrect).

TSH and free T4. Thyroid dysfunction is a common, treatable cause of fatigue. Reverse T3 if clinically indicated.

Vitamin B12 and folate. Low B12 produces fatigue and cognitive symptoms. Vegetarian/vegan diet and proton pump inhibitor use are common risk factors.

Vitamin D. 25-OH-D. Low levels associated with fatigue; supplementation in deficient individuals improves symptoms.

Comprehensive metabolic panel. Renal, hepatic, electrolyte abnormalities can produce fatigue.

Morning total testosterone. 8-10 AM, fasting. Hypogonadism produces fatigue, depression-like symptoms, and reduced exercise tolerance. Treatable.

HbA1c. Both hypoglycemia and uncontrolled diabetes can produce fatigue.

Sleep apnea screening. STOP-BANG questionnaire; home sleep study or in-lab polysomnography as indicated. Substantially under-diagnosed; CPAP often produces dramatic improvement.

Depression screening. PHQ-9. Depression often presents as fatigue.

More extensive workup if indicated. Celiac screening, autoimmune workup, cortisol/ACTH, Lyme/EBV/chronic infection workup, HIV testing in appropriate context, sleep study, MRI in selected cases.

Most chronic fatigue has identifiable cause on this workup. Address the cause; the supplement layer matters less when the underlying issue is resolved.

Step 2 — Lifestyle Foundation

Sleep. 7-9 hours, consistent schedule, dark room, no screens for 1+ hour before bed, avoid late caffeine, treat sleep apnea if present. The single highest-impact intervention for most fatigue. Cross-reference: sleep optimization monograph.

Exercise. Paradoxical: regular moderate exercise reduces fatigue. Sedentary status increases fatigue. Aerobic 3-5x/week + resistance 2-3x/week. Start where you are; build progressively.

Nutrition. Adequate calories (chronic underfeeding causes fatigue), adequate protein (1.2-2 g/kg), adequate carbohydrate timing for active individuals, address food sensitivities if symptomatic.

Alcohol reduction. Even modest regular use substantially affects sleep quality and energy.

Caffeine timing. Morning use can be productive; afternoon use disrupts sleep and creates dependence cycle.

Stress and recovery. Chronic stress without recovery produces fatigue. Adequate downtime, meditation/breathwork, social connection.

Step 3 — Treat Identified Underlying Conditions

If workup identified contributors, treat them:

  • Iron deficiency. Ferrous sulfate, ferrous bisglycinate, or IV iron in selected cases. Reassess in 3 months.
  • Thyroid dysfunction. Treat per evidence-based guidelines. Hypothyroidism with levothyroxine; consider T3 in selected refractory cases.
  • B12 or folate deficiency. Oral or IM B12, dietary folate or supplementation.
  • Vitamin D deficiency. Vitamin D3 to maintain 25-OH-D 30-50 ng/mL.
  • Hypogonadism. TRT in appropriate candidates. Cross-reference: TRT monograph.
  • Sleep apnea. CPAP or oral appliance. Dramatic improvement in many cases.
  • Depression. Per anxiety/mood protocol or formal psychiatric care.
  • Diabetes. Optimize glycemic control.

Step 4 — Mitochondrial and Cellular Energy Support

After foundation and underlying-condition optimization, supplement-layer support:

Creatine monohydrate. 3-5 g daily. Substantial evidence for cellular energy through ATP/phosphocreatine buffering. Effects in muscle, brain, and other high-energy tissues. Cross-reference: creatine monograph.

CoQ10 (ubiquinol). 100-200 mg/day. Substantial mitochondrial role. Evidence stronger in statin users (statins reduce endogenous CoQ10 synthesis), elderly populations, and some specific conditions. Cross-reference: CoQ10 monograph.

NAD+ precursors (NR or NMN). 250-1000 mg/day. Substantial mechanism interest; controlled outcome evidence in healthy populations more limited than marketing suggests. Reasonable trial in older adults. Cross-reference: NAD+ precursors monograph.

PQQ (pyrroloquinoline quinone). 10-20 mg/day. Mitochondrial biogenesis claims. Evidence modest. Often combined with CoQ10.

L-carnitine. 1-2 g/day. Role in mitochondrial fatty acid transport. Evidence for some conditions (deficiency states, some cardiomyopathy contexts). Modest in general populations.

Magnesium. 200-400 mg elemental. Role in ATP production. Many adults are deficient. Glycinate or threonate forms well-tolerated.

B-complex. Particularly thiamine, riboflavin, niacin, B6, B12, folate. Roles in mitochondrial function.

Step 5 — Adaptogens

Rhodiola rosea. 200-400 mg standardized extract. Evidence for fatigue and mild depression. Cross-reference: rhodiola monograph.

Ashwagandha. 300-600 mg standardized extract. Stress and cortisol modulation. Cross-reference: ashwagandha monograph.

Eleuthero, schisandra, holy basil. Various adaptogenic herbs with modest evidence. Often combined.

Cordyceps. Some evidence for exercise tolerance and fatigue. Quality variable across products.

Step 6 — Stimulants (Use Carefully)

Caffeine. Effective short-term energy support. Tolerance develops; dependence cycle common. Best used strategically rather than chronically.

L-theanine + caffeine. Smoother subjective effect than caffeine alone.

Modafinil. Prescription wakefulness agent. Substantial fatigue benefit; better suited to specific situations than chronic use. Cross-reference: modafinil monograph.

Prescription stimulants (methylphenidate, amphetamines). Reserved for diagnosed ADHD or selected medical contexts. Not appropriate for general fatigue management.

The Diagnostic-First Algorithm

Practical approach:

  • 1. Workup. Identify treatable underlying causes. Do not skip.
  • 2. Treat what workup identified.
  • 3. Lifestyle foundation. Sleep, exercise, nutrition, alcohol, caffeine, stress recovery.
  • 4. Mitochondrial/cellular layer if persistent: creatine, CoQ10, NAD+ precursors, magnesium, B-complex.
  • 5. Adaptogens for stress-related fatigue: rhodiola, ashwagandha.
  • 6. Strategic stimulant use if needed: caffeine + theanine, modafinil for specific situations.
  • 7. Specialist evaluation if persistent without clear cause.

Bottom Line

Chronic fatigue is typically a diagnosis problem, not a supplement problem. Workup first — thyroid, iron, B12, vitamin D, testosterone, sleep apnea, depression — produces the highest-yield interventions. Lifestyle foundation matters more than any single supplement. Mitochondrial support (creatine, CoQ10, NAD+ precursors) adds value once foundation is in place. Adaptogens have a role for stress-related fatigue. Stimulants strategic, not chronic. The protocol matters: most persistent fatigue resolves with diagnosis and underlying-condition optimization, not stim stacks.

Educational Disclaimer

This monograph is published by Vanguard Optimization as physician-led, evidence-based education. It is not medical advice. We do not prescribe, diagnose, or establish doctor–patient relationships. Decisions about supplementation or medication should be made with the clinician who knows you and your specific clinical situation. The signal-grading and editorial choices in this document represent our best read of the published literature as of May 2026; new data may change them.

Cross-Referenced Monographs

Sleep Optimization Protocol

Testosterone Replacement Therapy (TRT)

Creatine Monohydrate

CoQ10 and Ubiquinol

NAD+ Precursors (NR, NMN)

Rhodiola Rosea

Ashwagandha

Modafinil and Armodafinil