Browse all articles

Home Get the app
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 overview

Evidence overview 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.

Outcome Effect Evidence Dose Weeks Rank
Last longer before giving out Likely strong benefit
large 		6 meta-analyses n=444 Meta-analyzed 1.5–5000 g 1 wk #4/40
Stay independent longer with aging Large effect, needs confirmation
large 		1 RCT n=65 3000 mg 12 wk #5/25
Keep arteries flexible Likely modest benefit
small 		5 meta-analyses n=694 Meta-analyzed 9–21000 g 0–468 wk #2/37
Lower your blood pressure Faint early signal
small 		6 meta-analyses n=356 Meta-analyzed 1–6000 mg 6–8 wk —
Improve erection quality Faint early signal
small 		4 meta-analyses n=175 Meta-analyzed 1500–6000 mg 12 wk #6/8
Improve blood vessel relaxation Barely detectable
trivial 		4 meta-analyses n=522 Meta-analyzed 1–15000 g 1 wk #5/16
Raise peak oxygen capacity Likely real but unnoticeable
trivial 		3 meta-analyses n=327 Meta-analyzed 2–5000 g 3–4 wk #5/32
Hold power across repeated sprints Barely detectable
trivial 		2 RCTs n=46 0.05–6 g/kg 8 wk #6/14

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

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

Related

More evidence for Arginine

Want personalized recommendations?

Show me what works for me