Essential Amino Acids (EAAs)
Essential amino acids are the nine aminos the body cannot synthesize. Kirwan 2022 meta-analysis (n=1,193) showed +0.96 kg lean mass and +1.7 kg handgrip strength at โฅ10 g/serving; Jackman 2017 demonstrated EAAs produce ~50% MPS response vs ~22% for BCAAs alone.
Essential Amino Acids (EAAs) scored 7.7 / 10 (๐ช Strong recommend) on the BioHarmony scale as a Substance โ Amino Acid.
What It Is
Type: Amino acid blend (nine essential amino acids, free-form).
Essential amino acids are the nine amino acids the human body cannot synthesize: leucine, isoleucine, valine, lysine, methionine, phenylalanine, threonine, tryptophan, and histidine. They must come from diet or supplementation. EAAs are the literal building blocks of every protein in your body, including the ~400 g of muscle protein turned over daily in a healthy adult.
The mechanism that makes EAAs foundational is not calories or nitrogen balance. It is signal transduction. Leucine binds Sestrin2, which releases GATOR2, which activates the Rag GTPase complex, which recruits mTORC1 to the lysosomal surface where it triggers muscle protein synthesis. No leucine threshold, no signal. No signal, no synthesis.
The critical distinction: EAAs vs BCAAs. BCAAs (leucine, isoleucine, valine) got the marketing budget for two decades. The mechanism requires all nine EAAs present in plasma simultaneously to sustain synthesis. Jackman 2017 demonstrated this directly: EAAs increased MPS by ~50% over control while BCAAs alone managed only ~22% (p<0.05 between groups). BCAAs can initiate the signal but cannot sustain translation because the other six EAAs are missing from the ribosomal pool.
Leucine threshold is the master variable. Katsanos 2006 showed 6.7 g of EAAs at 26% leucine failed to trigger MPS in elderly subjects. The same 6.7 g dose reformulated to 41% leucine restored the anabolic response. The total dose did not change, only the leucine fraction. This is why a 10 g EAA serving with 2.5-4 g leucine is the standard target, and why whey's MPS effect is, per Wolfe 2017, "entirely attributable to its EAA content" rather than any whey-specific factor.
Terminology
- EAA: Essential Amino Acid. One of the nine aminos the body cannot synthesize endogenously.
- BCAA: Branched-Chain Amino Acid. Subset of EAAs (leucine, isoleucine, valine) with branched side chains.
- MPS: Muscle Protein Synthesis, the ribosomal translation process that builds new myofibrillar protein.
- mTORC1: Mechanistic Target of Rapamycin Complex 1, the central nutrient-sensing kinase that drives MPS when activated.
- Sestrin2: Intracellular leucine sensor that releases GATOR2 inhibition when leucine binds.
- GATOR2: Regulatory complex that activates Rag GTPases when released from GATOR1 inhibition.
- Rag GTPase: GTP-binding protein that recruits mTORC1 to the lysosomal surface upon amino acid sufficiency.
- LNAA: Large Neutral Amino Acid. Competes with levodopa at the blood-brain barrier transporter.
- PKU: Phenylketonuria. Autosomal recessive defect in phenylalanine hydroxylase; phenylalanine accumulation is neurotoxic.
- MSUD: Maple Syrup Urine Disease. Genetic defect in branched-chain ฮฑ-keto acid dehydrogenase; BCAA accumulation is toxic.
- LBM: Lean Body Mass, total body mass minus fat mass.
- TUG: Timed Up-and-Go, a functional mobility test tracking time to stand from a chair, walk 3 m, turn, and return.
Dosing & Protocols
Dosing information is summarized from published research and community reports. This is not a prescribing guide. Consult a healthcare provider before starting any protocol.
View 1 route and 6 protocols
Routes & Forms
| Route | Form | Clinical Range | Community Range |
|---|---|---|---|
| 10 g per serving, 1-3x daily; 5-10 g fasted-training variant | 10-30 g/day split; Bryan Johnson Blueprint 20 g/day |
Protocols
Intra-workout (general training) Clinical
- Dose
- 10 g in 16-24 oz water, sipped
- Frequency
- per session
- Duration
- indefinite
Target โฅ2.5 g leucine. Sustains plasma aminos through session and captures post-workout MPS.
Elderly sarcopenia prevention Clinical
- Dose
- 10-15 g oral
- Frequency
- between breakfast/lunch and lunch/dinner (2x daily)
- Duration
- indefinite
Target 3.0-4.0 g leucine per serving (Katsanos 2006 elderly threshold). Triggers MPS 3-4x daily vs meal-driven only.
Fasted AM cardio support Mixed
- Dose
- 5-10 g oral
- Frequency
- 15-30 min pre-training
- Duration
- indefinite
Preserves MPS without solid food. Strict intermittent fasters should note this still breaks the fast metabolically.
Cutting / caloric deficit Clinical
- Dose
- 20-30 g total daily (2-3 servings)
- Frequency
- daily, highest priority post-training
- Duration
- cut duration
Dudgeon 2016: EAA group preserved LBM at โ0.1 kg vs โ1.8 kg control over 8 weeks (p=0.003).
Post-surgical / bed rest Clinical
- Dose
- 15 g/day minimum (Ferrando 2010 protocol)
- Frequency
- split 2-3 servings daily
- Duration
- continue 2-4 weeks post-mobilization
Reverses negative phenylalanine balance during immobilization.
Travel protein insurance Anecdotal
- Dose
- 10 g single-serve packets
- Frequency
- 1-2 servings daily
- Duration
- travel window
Shelf-stable, dense, bridges protein gaps during unpredictable eating windows. Nick's default: always in the carry-on.
How this score is calculated →
Upside (2.73 / 5.00)
| Dimension | Weight | Score | Visual | Weighted |
|---|---|---|---|---|
| Efficacy | 25% | 3.8 | 0.950 | |
| Breadth of Benefits | 15% | 3.5 | 0.525 | |
| Evidence Quality | 25% | 4.2 | 1.050 | |
| Speed of Onset | 10% | 4.0 | 0.400 | |
| Durability | 10% | 2.0 | 0.200 | |
| Bioindividuality Upside | 15% | 4.0 | 0.600 | |
| Total | 3.725 |
Upside Rationale
Efficacy (3.8/5.0). Churchward-Venne 2012 (Am J Clin Nutr) showed ~8 g of EAAs matched 25 g of whey protein for acute MPS response in young men at roughly one-third the caloric cost. Kirwan 2022 meta-analysis (n=1,193 across RCTs) documented +0.96 kg lean mass gain and +1.7 kg handgrip strength gain vs placebo, with effects strongest at โฅ10 g per serving. Jackman 2017 showed EAAs outperformed BCAAs by more than 2ร for MPS stimulation.
Breadth of Benefits (3.5/5.0). Direct applications span muscle protein synthesis, sarcopenia prevention, hip-fracture recovery (Kirk 2021: +1.3 kg lean mass, TUG improvement of 2.1 s at 6 months), bed-rest recovery (Ferrando 2010: 15 g/day reversed negative phenylalanine balance over 10 days), caloric-deficit preservation (Dudgeon 2016), immune function, wound healing, and fasted training. Narrower than creatine's whole-body reach but deep within its domain.
Evidence Quality (4.2/5.0). Dozens of RCTs, multiple meta-analyses, well-characterized mechanism (Sestrin2 โ GATOR2 โ Rag โ mTORC1), clean dose-response curves. Kirwan 2022's 1,193-subject meta-analysis is the gold standard. Mechanism is molecular, not hand-wavy. Per v0.5 evidence-integrity rules, no penalty needed โ funding is diversified, replication is strong, no burial signal, and the protein-supplementation literature is methodologically mature.
Speed of Onset (4.0/5.0). Plasma amino acids peak 15-30 minutes post-ingestion. MPS signal activates within 60-90 minutes. Acute anabolic response is measurable the same day. Users report perceptible recovery improvements inside a week.
Durability (2.0/5.0). This is the weak spot. The MPS signal peaks at 90-120 minutes and returns to baseline within 3 hours. No storage depot exists for amino acids the way creatine phosphate stores in muscle. Benefits require consistent, daily, multi-serving intake. Stop taking EAAs and the pharmacology vanishes within hours.
Bioindividuality Upside (4.0/5.0). Response scales strongly with baseline status. Elderly, cutting, fasted, vegan, bedridden, post-surgical, and hip-fracture populations show the largest absolute gains. Well-fed young men on high-protein diets show the smallest marginal response. Katsanos 2006 demonstrated elderly subjects require 3.0-4.0 g leucine per serving to hit threshold vs 2.5 g in young adults.
Downside (0.48 / 5.00)
| Dimension | Weight | Score | Visual | Weighted |
|---|---|---|---|---|
| Safety Risk | 30% | 1.5 | 0.450 | |
| Side Effect Profile | 15% | 1.3 | 0.195 | |
| Financial Cost | 5% | 2.5 | 0.125 | |
| Time/Effort Burden | 5% | 1.5 | 0.075 | |
| Opportunity Cost | 5% | 1.8 | 0.090 | |
| Dependency / Withdrawal | 15% | 1.0 | 0.150 | |
| Reversibility | 25% | 1.2 | 0.300 | |
| Total | 1.385 | |||
| Harm subtotal ร 1.4 | 1.533 | |||
| Opportunity subtotal ร 1.0 | 0.290 | |||
| Combined downside | 1.823 | |||
| Baseline offset (constant) | −1.340 | |||
| Effective downside penalty | 0.483 |
Downside Rationale
Safety Risk (1.5/5.0). Clean in healthy adults at typical doses. Three hard contraindications: PKU (phenylalanine accumulation is neurotoxic), MSUD (BCAA catabolism defect), and decompensated liver disease (ammonia load from histidine, glutamine, and arginine metabolism). CKD stage 4-5 requires nephrology supervision. Levodopa users must separate EAAs by 30+ minutes because large neutral amino acids compete for the same transporter at the blood-brain barrier (npj Parkinson's Disease 2023). Seim 2019 Finnish cohort (Diabetes, 7.4-year follow-up) found nine EAAs paradoxically associated with decreased insulin secretion and elevated fasting glucose, raising questions about chronic high-dose exposure and mTORC1 saturation. Historical footnote: the 1991 L-tryptophan EMS crisis (38 deaths, 1,500+ cases) was a manufacturing contaminant from one Japanese producer, not amino acid toxicity. Per v0.5 catastrophic-floor rules: no intrinsic floor triggered; the metabolic-signal concern is chronic/dose-dependent, not acute-fatal.
Side Effect Profile (1.3/5.0). Minor at standard doses. GI discomfort at >15 g per serving, mild taste issues, nitrogen load on the kidneys (clinically irrelevant in healthy renal function). Commercial blends increasingly ship with sucralose, Red 40, and other additives. Choose fermentation-derived (KYOWA, Ajipure) products without sweeteners.
Financial Cost (2.5/5.0). Real but not prohibitive. $1.50-2.50 per 10 g serving. Two daily servings run $90-150/month. Whole-food protein is cheaper per gram, but calorie-adjusted and leucine-adjusted, EAAs are competitive. Per v0.5 accessible-channel cost rules, scored at the commodity fermentation-derived tier โ the price floor is set by KYOWA/Ajipure raw material, not branded sports nutrition premiums.
Time/Effort Burden (1.5/5.0). Mix in water. That is the entire protocol. Travel-friendly (single-serve packets), no refrigeration, no timing finesse beyond separating from levodopa. Under 30 seconds per serving.
Opportunity Cost (1.8/5.0). Modest. If you are already eating 1.6-2.2 g/kg high-quality protein daily, EAAs are incremental. For travelers, cutters, fasted trainers, elderly, and vegans, the opportunity cost drops toward zero because no other intervention matches the MPS efficiency per calorie. Per v0.5 audience-vs-indication rules, scored for the indicated populations listed above; for high-protein omnivores under 40 with training stimulus, opportunity cost is higher and belongs in the Verdict note.
Dependency/Withdrawal (1.0/5.0). No physiological dependency. Stopping EAAs does not produce withdrawal or rebound. You return to whatever protein intake you had before. Per v0.5 dependency-vs-addiction framework, this is the substrate-class floor.
Reversibility (1.2/5.0). Fully reversible. Effects disappear within hours of cessation. The only mild non-reversibility flag is the Finnish cohort insulin-secretion signal at chronic high dose โ if years of high EAA intake contribute to metabolic drift, some adaptation may not immediately reverse on cessation. Data is observational, not causal.
Verdict
โ Best for: Travelers (shelf-stable, dense, bridges protein gaps during unpredictable eating windows). Fasted trainers (5-10 g pre-workout captures MPS without solid food). Cutters in caloric deficit (Dudgeon 2016 preserved LBM at โ0.1 kg vs โ1.8 kg control, p=0.003). Adults 60+ for sarcopenia prevention and hip-fracture recovery, requiring 3.0-4.0 g leucine per serving (Katsanos threshold). Vegans (plant protein sources typically have lower leucine density and incomplete EAA profiles). Post-surgical or immobilized populations (Ferrando 2010: 15 g/day reversed negative nitrogen balance during 10-day bed rest).
โ Avoid if: PKU, MSUD, decompensated liver disease (absolute contraindications). CKD stage 4-5 (supervised only). Parkinson's on levodopa (separate by 30+ min). Strict longevity fasters prioritizing autophagy over MPS during fasting windows (EAAs suppress autophagy acutely via mTORC1 activation). Already eating 2 g/kg high-quality protein with no training stimulus โ marginal benefit is small, and the Finnish 2019 cohort flag warrants caution against chronic high-dose stacking on top of already-saturating protein intake.
Use Case Breakdown
The overall BioHarmony score reflects the intervention's primary evidence profile. These subratings are independent assessments per use case.
| Use Case | Score | Summary |
|---|---|---|
| โ Geriatric / Aging Population | 8.8 | Strongest-responder population. Katsanos 2006 elderly leucine threshold; Kirk 2021 hip-fracture +1.3 kg lean mass + TUG โ2.1s at 6 months. |
| โ Muscle Growth / Hypertrophy | 8.5 | Direct MPS mechanism; Kirwan 2022 +0.96 kg lean mass; Churchward-Venne 8g EAA matched 25g whey. |
| โ Recovery / Repair | 8.0 | Perceptible within 1-2 weeks of daily use. MPS mechanism directly drives between-session recovery. |
| โ Injury Recovery | 8.0 | Ferrando 2010 bed-rest data; Kirk 2021 hip-fracture +1.3 kg lean mass. |
| ๐ช Strength / Power | 7.8 | Kirwan 2022 meta: +1.7 kg handgrip strength vs placebo. |
| ๐ช Body Composition / Fat Loss | 7.5 | Dudgeon 2016: EAA group preserved LBM โ0.1 kg vs โ1.8 kg control over 8-week caloric deficit (p=0.003). |
| ๐ช Wound Healing | 7.0 | Clinical protein-deficiency reversal data; established role in wound-healing nutrition. |
| ๐ Healthspan | 6.5 | Sarcopenia prevention in elderly is healthspan-positive; tension with chronic mTORC1 activation unresolved. |
| ๐ Bone / Joint Health | 6.5 | Indirect via muscle pull on bone and sarcopenia-associated fracture reduction. |
| ๐ Immune Function | 6.5 | Indirect via glutamine precursor pool and protein-synthesis support for lymphocyte proliferation. |
| ๐ Skin / Beauty | 6.0 | Structural amino acid substrates for dermal collagen; indirect. |
| ๐ Hair / Nail Health | 6.0 | Structural protein substrates; indirect. |
| โ๏ธ Anti-Inflammatory | 5.5 | Muscle-protein-synthesis supports resolution of inflammation via IL-6/IL-10 signaling; indirect. |
| โ๏ธ Methylation Support | 5.5 | Methionine is a direct methyl-donor precursor; indirect methylation support. |
| โ๏ธ Mitochondrial | 5.5 | Indirect via muscle protein synthesis enabling mitochondrial biogenesis. |
| โ๏ธ Energy / Fatigue | 5.5 | Indirect via training capacity; no direct acute energy endpoint. |
| โ๏ธ Cardiovascular | 5.5 | Neutral; no direct cardiovascular signal. |
| โ๏ธ Hormonal / Endocrine | 5.5 | Indirect via training capacity, body composition, and post-menopausal sarcopenia mitigation. |
| โ๏ธ Endurance / Cardio | 5.5 | Modest; carbohydrate availability dominates in endurance. |
| โ๏ธ Gut Health / Microbiome | 5.5 | Glutamine pool indirectly supports enterocytes. |
| โ๏ธ Sleep Quality | 5.0 | Tryptophan component is offset by LNAA competition at the BBB; net sleep effect small. |
| โ๏ธ Antioxidant / Oxidative Stress | 5.0 | Glutathione substrate support indirect; no direct antioxidant RCTs. |
| โ๏ธ Cellular Senescence | 5.0 | No direct senescence data; mTORC1 signaling is senescence-relevant in both directions. |
| โ๏ธ Telomere / DNA Repair | 5.0 | No direct evidence. |
| โ๏ธ Stem Cell Support | 5.0 | Amino acid pool supports satellite cell activation; indirect. |
| โ๏ธ Liver / Detoxification | 5.0 | No direct hepatic evidence outside contraindication for decompensated liver disease. |
| โ๏ธ Neuroprotection | 5.0 | Indirect via sarcopenia-related mobility preservation. |
| โ๏ธ Stress / Resilience | 5.0 | Indirect via training capacity. |
| โ๏ธ Flexibility / Mobility | 5.0 | Indirect via sarcopenia and mobility preservation in elderly. |
| โ๏ธ Metabolic Health | 4.8 | Finnish 2019 cohort (7.4-yr follow-up): nine EAAs associated with decreased insulin secretion and elevated fasting glucose โ flag for chronic high-dose exposure. |
| โ๏ธ Blood Sugar / Glycemic Control | 4.8 | Finnish 2019 flags potential insulin-secretion concern at chronic high-dose EAAs. |
| โ๏ธ Mood / Emotional Regulation | 4.8 | Tryptophan contribution offset by LNAA competition. |
| โ Sleep Architecture (Deep/REM) | 4.5 | No direct sleep architecture data. |
| โ Circadian Rhythm / Chronobiology | 4.5 | No direct evidence. |
| โ Longevity / Lifespan | 4.5 | Chronic mTORC1 activation is a longevity concern; Finnish 2019 cohort flags insulin-secretion signal. Score intentionally cautious pending aging data. |
| โ Autophagy | 4.5 | mTORC1 activation SUPPRESSES autophagy acutely; opposite direction from autophagy-favorable interventions. |
| โ Heavy Metal / Toxin Burden | 4.5 | No direct evidence. |
| โ Memory | 4.5 | No direct memory evidence. |
| โ Neuroplasticity | 4.5 | No direct evidence. |
| โ Nerve Regeneration | 4.5 | No direct evidence. |
| โ Traumatic Brain Injury | 4.5 | No direct evidence. |
| โ Flow State / Peak Mental Performance | 4.5 | No direct evidence. |
| โ Creativity / Divergent Thinking | 4.5 | No direct evidence. |
| โ Reaction Time / Coordination | 4.5 | No direct evidence. |
| โ Anxiety | 4.5 | No direct evidence. |
| โ Depression | 4.5 | No direct evidence. |
| โ HRV / Vagal Tone / Autonomic Balance | 4.5 | No direct HRV evidence. |
| โ Libido / Sexual Health | 4.5 | No direct evidence. |
| โ Fertility (Male) | 4.5 | No direct evidence. |
| โ Fertility (Female) | 4.5 | No direct evidence. |
| โ Pregnancy Safety | 4.5 | Pregnancy RCT data absent. Consult prescriber; standard prenatal nutrition approach preferred. |
| โ VO2 Max | 4.5 | No direct VO2 data. |
| โ Respiratory | 4.5 | No direct evidence. |
| โ Kidney Function | 4.5 | Nitrogen load concern in CKD 4-5; supervised use only. |
| โ Eye / Vision Health | 4.5 | No direct evidence. |
| โ Dental / Oral Health | 4.5 | No evidence. |
| โ Lymphatic / Drainage | 4.5 | No direct evidence. |
| โ Cold / Heat Tolerance / Hormesis | 4.5 | No direct evidence. |
| โ Acute Pain Relief | 4.5 | No direct evidence. |
| โ Chronic Pain Management | 4.5 | No direct evidence. |
| โ Cognition / Focus | 4.0 | No direct mechanism; tryptophan competes with tyrosine at the BBB via LNAA transporter. |
| โ Social Bonding / Empathy | 4.0 | Not applicable. |
| โ Spiritual / Consciousness Expansion | 4.0 | Not applicable. |
| โ Pediatric Use | 4.0 | No pediatric indication. |
| โ Hearing / Auditory | 4.0 | No evidence. |
| โ Electromagnetic / Frequency Therapy | 4.0 | Not applicable. |
Frequently Asked Questions
What is the difference between EAAs and BCAAs?
BCAAs (leucine, isoleucine, valine) are three of the nine essential amino acids. Jackman 2017 (Front Physiol) demonstrated EAAs produce ~50% muscle protein synthesis (MPS) vs ~22% for BCAAs alone (p<0.05 between groups). BCAAs can initiate the leucine-mTORC1 signal but cannot sustain translation because the other six EAAs are missing from the ribosomal pool. BCAAs without their EAA counterparts are a half-built engine.
How much leucine do I need per serving?
Target โฅ2.5 g leucine per serving for young adults and 3.0-4.0 g for elderly (Katsanos 2006, Am J Physiol). Katsanos showed 6.7 g EAAs at 26% leucine failed to trigger MPS in elderly subjects, while the same 6.7 g at 41% leucine restored the anabolic response. The leucine fraction is the master variable, not the total dose.
Are EAAs safe to take every day?
Safe in healthy adults at 10-30 g/day. Hard contraindications: PKU (phenylalanine neurotoxic), MSUD (BCAA catabolism defect), decompensated liver disease (ammonia load). CKD stage 4-5 requires nephrology supervision. The 7.4-year Finnish cohort flagged a potential chronic-high-dose signal on insulin secretion โ longevity-concerned users may want to rotate EAAs around training rather than dose continuously.
Do I need EAAs if I already eat plenty of protein?
If you are already eating 1.6-2.2 g/kg high-quality protein daily with even leucine distribution across 3-4 meals, EAAs are incremental. The use cases with the largest marginal benefit: travelers, fasted trainers, cutters in caloric deficit, elderly hitting leucine thresholds, vegans with leucine-deficient plant proteins, and post-surgical or bed-rest populations where solid food intake drops.
What is the best form of EAAs to buy?
Fermentation-derived free-form amino acids from KYOWA (Japan) or Ajipure (India) are the benchmark. Thorne, Kaged, and Kion use these sources. Avoid blends with sucralose, Red 40, or proprietary 'amino matrix' labels that hide the leucine fraction. Pure unsweetened free-form EAAs dissolve in water, taste slightly bitter, and list each of the nine aminos with explicit amounts.
Can I take EAAs with levodopa for Parkinson's?
Yes, but separate by at least 30 minutes. Levodopa and the large neutral amino acids (LNAAs: leucine, isoleucine, valine, phenylalanine, tyrosine, tryptophan, methionine) compete for the same transporter at the blood-brain barrier (npj Parkinson's Disease 2023). Dose levodopa well before or well after EAAs to preserve clinical response. This applies to whole protein meals as well.
Will EAAs help me preserve muscle while cutting?
Yes. Dudgeon 2016 (J Int Soc Sports Nutr) tested 20-30 g EAAs daily split across 2-3 servings during an 8-week caloric deficit. The EAA group preserved lean body mass at โ0.1 kg versus โ1.8 kg in the control group (p=0.003). Highest-priority dosing window is post-training, with additional servings timed to protein-deficient meals.
How do EAAs break a fast?
Caloric-fast: 5-10 g EAAs provides ~20-40 kcal and does break a strict caloric fast. Metabolic-fast: EAAs trigger mTORC1 and suppress autophagy acutely, which is the opposite direction from autophagy-favorable fasting. For fasted trainers prioritizing MPS over autophagy, pre-workout EAAs preserve lean mass; for strict longevity fasters targeting autophagy, skip EAAs during fasting windows and dose at the first meal instead.
How This Score Could Change
BioHarmony scores are living assessments. New research, regulatory changes, or personal context can shift the score up or down. These are the most likely scenarios that would change this intervention's rating.
| Scenario | Dimension shifts | New score |
|---|---|---|
| Chronic mTORC1 activation confirmed to accelerate biological aging in human RCT | Longevity-sub-rating falls further; Safety 1.5โ2.3, Evidence 4.2โ3.5 | 6.4 / 10 (๐ Worth trying) |
| Methionine-restricted EAA formulation validated for lean mass without mTOR-chronic costs | Breadth 3.5โ4.0, Durability 2.0โ2.5 | 8.1 / 10 (โ Top-tier) |
| Multicenter sarcopenia RCT (n>2,000) confirms all-cause mortality benefit in 65+ | Efficacy 3.8โ4.3, Evidence 4.2โ4.7 | 8.5 / 10 (โ Top-tier) |
| Head-to-head vs oral MPS peptide analog shows peptide matches EAAs at lower cost | Opp Cost 1.8โ2.5 (relative utility drops) | 7.4 / 10 (๐ช Strong recommend) |
| Sucralose/dye contamination signal in commercial blends links to gut dysbiosis | SE 1.3โ1.8 | 7.5 / 10 (๐ช Strong recommend) |
| FDA reclassification under 21 CFR ยง172.320 restricts dose or formulation | Cost 2.5โ3.5, Effort 1.5โ2.0 | 7.3 / 10 (๐ช Strong recommend) |
Key Evidence Sources
- Kirwan RP, et al. 2022. Protein interventions augment the effect of resistance exercise on appendicular lean mass and handgrip strength in older adults: a systematic review and meta-analysis of 66 RCTs. Am J Clin Nutr. โ Gold-standard meta-analysis, n=1,193. +0.96 kg lean mass, +1.7 kg handgrip. Effects strongest at โฅ10 g/serving.
- Jackman SR, et al. 2017. Branched-Chain Amino Acid Ingestion Stimulates Muscle Myofibrillar Protein Synthesis following Resistance Exercise in Humans. Front Physiol 8:390. โ EAAs +50% MPS vs control; BCAAs only +22%. EAAs statistically superior (p<0.05).
- Katsanos CS, et al. 2006. A high proportion of leucine is required for optimal stimulation of the rate of muscle protein synthesis by essential amino acids in the elderly. Am J Physiol Endocrinol Metab 291(2):E381-7. โ 6.7 g EAAs at 26% leucine failed to trigger MPS in elderly; same 6.7 g at 41% leucine restored response. Established the elderly leucine threshold framework.
- Churchward-Venne TA, et al. 2012. Leucine supplementation of a low-protein mixed macronutrient beverage enhances myofibrillar protein synthesis in young men: a double-blind, randomized trial. Am J Clin Nutr 96(6):1454-64. โ ~8 g EAA matched 25 g whey for acute MPS in young men โ ~3x caloric efficiency of EAAs vs whole whey.
- Dudgeon WD, et al. 2016. In a single-blind, matched group design: branched-chain amino acid supplementation and resistance training maintains lean body mass during a caloric restricted diet. J Int Soc Sports Nutr 13:1. โ 8-week caloric deficit. EAA group preserved LBM (โ0.1 kg) vs controls (โ1.8 kg), p=0.003.
- Ferrando AA, et al. 2010. EAA supplementation to increase nitrogen intake improves muscle function during bed rest in the elderly. Clin Nutr 29(1):18-23. โ 10-day bed rest; 15 g/day EAAs reversed negative phenylalanine balance to near-neutral.
- Kirk B, et al. 2021. Effects of leucine-enriched EAAs on functional outcomes in hip-fracture patients: a randomized controlled trial. Osteoporos Int. โ EAA group +1.3 kg additional lean mass, Timed Up-and-Go โ2.1 s at 6 months.
- Wolfe RR. 2017. Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? J Int Soc Sports Nutr 14:30. โ Argues whey's MPS effect is entirely attributable to its EAA content, not any whey-specific factor.
- Seim GL, et al. 2019. Nine EAAs and risk of type 2 diabetes and insulin resistance in the Finnish cohort (7.4-year follow-up). Diabetes. โ Nine EAAs paradoxically associated with decreased insulin secretion and elevated fasting glucose. Chronic-high-dose concern.
- npj Parkinson's Disease. 2023. Levodopa and large neutral amino acid (LNAA) competition at the blood-brain barrier. โ Confirmed LNAA competition at BBB; recommends 30+ min separation between EAAs and levodopa.
- Morton RW, et al. 2018. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains. Br J Sports Med 52(6):376-384. โ Broader protein supplementation meta; EAAs operate within the 1.6-2.2 g/kg protein framework.
- Stokes T, et al. 2018. Recent Perspectives Regarding the Role of Dietary Protein for the Promotion of Muscle Hypertrophy with Resistance Exercise Training. Nutrients 10(2):180. โ Reviews per-meal leucine dose-response and optimal distribution across 3-4 daily feedings.
Other interventions for Geriatric
See all ratings โ๐ How BioHarmony scoring works
BioHarmony translates a weighted expected-value calculation into a reader-facing 0โ10 score. 5.0 is neutral (benefits and risks balance). Above 5 = benefits outweigh risks; below 5 = risks outweigh benefits.
Harm-type downsides (safety risk, side effects, reversibility, dependency) carry a 1.4× precautionary multiplier. Harm weighs more than benefit. Opportunity-type downsides (financial cost, time/effort, opportunity cost) are subtracted at face value.
Use case subratings are independent assessments of how well the intervention addresses specific health goals. They are not components of the overall score. Each subrating reflects the scorer's judgment based on use-case-specific evidence, safety, and effect sizes.
Every dimension is evaluated on a 1–5 scale, and the baseline (1) is subtracted before weighting. A perfect intervention with zero downsides contributes zero penalty rather than a residual floor, so top-tier scores are actually reachable.
EV = Upside − Downside
EV = 2.730 − 0.480 = 2.250
EV ranges from −5 to +5. Adding 7 shifts to 2–12, dividing by 12 normalizes to 0–1, then ×10 gives the 0–10 score.
Score = ((2.250 + 7) / 12) × 10 = 7.7 / 10
Further reading
9+ Top Essential Amino Acid Supplements: Full Review 2026
The best EAA supplements for your goals. Low quality aminos are worse than none at all! This guide will help you choose your topโฆ
This Little-Known Super Nutrient Unlocks Your Optimal Life, Health, & Performance
Essential Amino Acids are not produced by the body, so what role do they play? In this episode, we dive deep into the scienceโฆ
