Performance Dietary supplementNon-Essential Amino Acid

L-Citrulline

Citrulline Malate · Citrulline

Evidence: Studied in humans. Example dose: finalize with a provider. Not a fact-check stamp.

6-8g pre-workout – 6-8 g Oral 1-2x daily

Arginine Precursor (bypasses intestinal arginase)Performance / Pump Supplement

L-Citrulline is a non-essential amino acid that the body converts to L-Arginine in the kidney, bypassing intestinal arginase metabolism. This makes oral L-Citrulline more effective than L-Arginine at raising plasma arginine and supporting nitric oxide production. Citrulline Malate (1:1 or 2:1 ratio with malic acid) is the most-studied form, used widely in pre-workout supplements and clinical research.

Quick Start

Route

Oral powder or capsule

Start low

6-8g Oral

Frequency

1-2x daily

Timing

Independent (works fasted or fed)

30-60 min pre-workout.

❋

Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.

Tiered Protocols · lowest first

Conservative start

6-8g pre-workout · Oral powder or capsule · 1-2x daily

conservative starter

6-8g pre-workout

1-2x daily

Standard

Vasodilation & Pump

6-8 g · Oral · Daily

human clinical trial · Pérez-Guisado & Jakeman 2010 (J Strength Cond Res 24(5):1215-1222)

Citrulline Malate requires higher dosing (~8g) to get 6g of pure L-Citrulline. Vastly superior to L-Arginine for systemic vasodilation.

6-8 g

Daily

◆

How it works

L-Citrulline produces higher plasma arginine than equimolar L-Arginine:

Bypassing Intestinal Arginase

Oral L-Citrulline is absorbed intact (no intestinal metabolism) and converted to L-Arginine in the kidney via the urea cycle. Plasma arginine rises ~50% higher than from equimolar L-Arginine.

Sustained NO Substrate

The renal conversion provides sustained substrate for NOS - extends NO availability vs L-Arginine's peak-and-fall pattern.

Performance Effects

Pre-workout citrulline malate (6-8g) consistently improves bench press reps, reduces soreness, and improves perceived exertion in resistance training.

Cardiovascular

Sustained NO support produces modest BP reduction (~5-10 mmHg) and improved endothelial function.

Malate Component (in Citrulline Malate)

Provides Krebs cycle intermediate - may contribute to performance benefit beyond NO mechanism.

Better Tolerability

Citrulline does not produce the GI upset common with L-Arginine - much better tolerated at therapeutic doses.

What to expect

Early

Days 1–7

Acute pre-workout effect within 30-60 min.

Mid

Weeks 2–4

Weeks: cumulative cardiovascular benefits.

Later

Weeks 4–12

Long-term: sustained effects with continued use.

Evidence

HumanStrong

AnimalPresent

In-vitroPresent

Each reference below was re-fetched from its PubMed record, and the quoted sentence was confirmed to appear in that abstract and to support the claim it sits under. Follow any of them to read the source.

Evidence boundary from the checked abstract: Watermelon and L-citrulline supplementation reduced blood pressure in human trials.

Watermelon and L-citrulline supplementation reduced blood pressure in human trials.

Watermelon and L-Citrulline in Cardio-Metabolic Health: Review of the Evidence 2000-2020. Current atherosclerosis reports · 2021 · PMID 34894302

Evidence scope. This entry supports only the exact statement quoted from the live abstract; it does not independently verify OnePin's displayed dose, route, frequency, formulation, population, or broader mechanism.

Claims we could not support

No abstract we checked supports these for this molecule at this route. That is not the same as saying they are false — it marks where the evidence is missing.

Dose/route: 6-8g pre-workout; Oral powder or capsule; 1-2x daily. No checked live PubMed abstract verified this exact displayed dose, route, and frequency for the same molecule/formulation and relevant population.

Primary safety claim: No primary safety text present in source JSON. No checked live PubMed abstract directly verified this source-JSON safety claim at the displayed formulation, route, and regimen.

Side effects & safety

Commonly reported

Generally well-tolerated
Possible mild GI at very high doses

Less common & notes

Allergic reactions rare.
Better tolerated than L-Arginine.
Long-term safety good.

Pharmacokinetics

Illustrative plasma concentration · 8 h

Half-life

~1-2 hours

Plasma

Peak · Tmax

1-2 hours

Post-ingestion

Elimination

Hours plasma; arginine elevation sustained 4-8 hours

Bioavailability

Oral ~80% (no intestinal arginase metabolism)

Duration of action

4-8 hours

Per dose

Clearance

Renal conversion to arginine + tissue uptake

Storage. Powder/capsule. Cool dry location.

Regulatory status

Dietary supplement (US, DSHEA). Naturally found in watermelon.

Put it to work

Calculate, log & track

Open L-Citrulline straight into OnePin with your vial and dose pre-filled, then let it handle the syringe math and remind you before the vial runs out.

Open L-Citrulline in the app →

Go deeper

The guide & community

The complete L-Citrulline walkthrough, real protocol discussion and coaching live inside the BlessUp community on Skool.

Join the community ↗

Open in app Community