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Arginine

Arginine

Best for

Last longer before giving out

Likely strong benefit · 1.5–5000 g/day for 1 weeks · 2 meta-analyses , n=444

50 papers · 8 claims · 117 outcomes scored · 8 positive

Evidence summary

Evidence summary Likely strong benefit

Arginine offers a likely strong benefit for exercise endurance and some blood-flow measures, while blood pressure and erection-quality effects stay modest.

  • Across 6 studies (n=444), arginine improved endurance endpoints, the strongest signal in the evidence base.4
  • The research footprint spans 50 papers and 117 outcomes across exercise, blood pressure, erection, and vascular measures.
  • Blood-pressure and erection-quality effects stay modest, so arginine is not a universal performance enhancer.

Outcomes

What arginine actually does, by outcome

Each row is one outcome with effect size, evidence base, the dose that worked in trials, and time to first effect. Magnitude tiers come from native-unit MCID where available, Cohen's d otherwise.

Last longer before giving out Likely strong benefit

More reps, more miles, and a higher ceiling before fatigue forces you to stop.

6 meta-analyses n=444 1.5–5000 g 1 wk #4/40
25177096·35308069·35457330·39796467 +2 more
Stay independent longer with aging Large effect, needs confirmation

Bathing, dressing, climbing stairs, and daily tasks stay within reach.

1 RCT n=65 3000 mg 12 wk #5/25
36449096
Keep arteries flexible Likely modest benefit

Artery walls that stretch and recoil absorb each heartbeat smoothly.

5 meta-analyses n=694 9–21000 g 0–468 wk #2/37
19651674·29052766·30577559·35691183 +1 more
Lower your blood pressure Faint early signal

Brings down both systolic and diastolic, especially when baseline runs high.

6 meta-analyses n=356 1–6000 mg 6–8 wk
26578409·26889456·28751963·34967840 +2 more
Improve erection quality Faint early signal

Blood flow and nerve signaling work together instead of fighting you.

4 meta-analyses n=175 1500–6000 mg 12 wk #6/8
32192966·34973154·37686709·39279185
Improve blood vessel relaxation Barely detectable

Boosts nitric oxide where you need it for circulation, dials it back where it causes harm.

4 meta-analyses n=522 1–15000 g 1 wk #5/16
22691607·30577559·35457330·39800868
Raise peak oxygen capacity Likely real but unnoticeable

Higher aerobic ceiling gives more headroom at race pace.

3 meta-analyses n=327 2–5000 g 3–4 wk #5/32
25177096·33587327·33815657
Hold power across repeated sprints Barely detectable

Burst speed and power fade less as efforts stack up.

2 RCTs n=46 0.05–6 g/kg 8 wk #6/14
39714103·41245968

The app checks whether your arginine dose clears the ranges that worked in these trials — score my stack at launch →

Forms & standardisation

Plain oral L-arginine has the clearest human evidence, so the label should tell you the actual grams of L-arginine per serving.234 Skip vague proprietary blends if you want to match the trial doses, because the studies use real, counted amounts, not marketing fluff.

Risk profile

Adverse events and known drug interactions

Safety events

Hospitalization for asthma exacerbation severe
pneumothorax severe
non-ST elevation myocardial infarction (NSTEMI) severe
pulmonary thromboembolism (PTE) severe
dyspepsia moderate
herpes zoster ophthalmicus (HZO), recurrent moderate
Dysphagia leading to withdrawal moderate
Hives (urticaria) leading to withdrawal moderate

Drug interactions

Nitroglycerin moderate increases effect
Antihypertensives moderate increases effect
Pravastatin moderate increases effect
Simvastatin minor unknown
Riluzole
Edaravone

Co-studied with

Supplements that share evidence with arginine

Frequently asked

Common questions

Does arginine really help blood flow?

Yes, but the effect stays modest. Trials tie oral arginine to small changes in blood pressure, vascular flexibility, and erection quality, which fits its nitric-oxide role.123

How long does arginine take to work?

Most study protocols run for 6-12 weeks, so you judge it on a block of daily use, not one serving.234

Should you take arginine before a workout?

Workout studies usually use it daily and often before exercise or split across the day. It behaves more like a training-block supplement than a one-off preworkout.4

What is the best form of arginine?

Plain L-arginine has the clearest human data. Look for a label that tells you the actual grams of L-arginine, not just a "pump blend" with a tiny amount hidden inside.234

Track arginine in the app

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Sources

  1. 1. PubMed search, L-arginine nitric oxide endothelial function
  2. 2. PubMed search, L-arginine blood pressure meta-analysis
  3. 3. PubMed search, L-arginine erectile function meta-analysis
  4. 4. PubMed search, L-arginine exercise performance meta-analysis
  5. 5. PubMed search, L-arginine arterial stiffness meta-analysis

Generated May 15, 2026

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