Arginine vs Citrulline: Which Is Better for Performance?

Key Takeaways for Athletes

1. L-citrulline outperforms L-arginine because it bypasses liver breakdown and delivers much higher usable arginine in your blood.
2. Citrulline can boost reps to failure by up to 53% in lifting and extend time to exhaustion by about 12% in cyclists.
3. Most athletes see results with 3–6 g pure L-citrulline or 6–8 g citrulline malate, taken about 60 minutes before training.
4. Citrulline supports better pumps, less soreness, lower ammonia buildup, and smoother recovery between sessions.
5. Choose Bucked Up’s clinically dosed L-Citrulline to upgrade pumps, endurance, and recovery in every training session.

How Arginine and Citrulline Work in Your Body

L-arginine is a semi-essential amino acid and a direct precursor to nitric oxide. However, L-arginine undergoes extensive presystemic and systemic elimination in the gut and liver, with only 5%–15% of plasma arginine from de novo synthesis. This heavy breakdown in the digestive tract limits how much arginine your body can actually use for performance.

L-citrulline, first isolated from watermelon, follows a more efficient route. L-citrulline avoids gut and liver first-pass metabolism, being converted enzymatically to L-arginine in the kidneys. This bypass lets citrulline raise plasma arginine levels two to three times more effectively than taking arginine itself.

Bucked Up promotes clinical dosing of science-backed ingredients, including Citrulline Malate and Pure L-Citrulline. Find the L-citrulline option that fits your training style.

Why L-Citrulline Outperforms L-Arginine

Citrulline’s main advantage comes from its superior bioavailability and unique metabolic pathway. Citrulline has superior bioavailability to arginine, bypassing gut and liver metabolism (which eliminates about 70% of arginine), with nearly all citrulline reaching plasma. The kidneys then convert citrulline to arginine, away from the arginase enzymes that rapidly break arginine down.

The malate in citrulline malate adds another layer of support. Through the Krebs cycle, malate helps ATP production and can reduce ammonia buildup during hard training. Citrulline supplementation boosts plasma arginine levels by 30–35%, making it more effective for raising blood arginine than direct L-arginine intake. This steady arginine supply keeps nitric oxide production going throughout your workout.

Citrulline also plays a role in the urea cycle, which helps clear ammonia, a major driver of muscle fatigue. Faster removal of this waste supports both performance and recovery in ways arginine rarely matches in studies.

How L-Citrulline Supports Real-World Performance

Citrulline’s performance benefits show up across strength, endurance, and mixed training. Benefits include improved VO₂ kinetics, reduced perceived exertion, and enhanced exercise tolerance in trained athletes. Higher nitric oxide levels improve blood flow, which supports better oxygen and nutrient delivery to working muscles.

In resistance training, citrulline malate stands out. Studies using 8 g of citrulline malate report up to 53% more repetitions to failure across multiple sets. This effect likely comes from stronger blood flow, fewer fatigue metabolites, and extra energy support from the malate component.

Endurance athletes also see clear benefits. Research shows cyclists using citrulline can extend time to exhaustion by about 12% while holding higher power outputs. Improved VO₂ kinetics help them use oxygen more efficiently during long efforts.

Recovery improves as well. Studies confirm citrulline reduces muscle soreness and enhances recovery through better lactate clearance and lower inflammatory markers. Athletes can return to hard training sooner and adapt more effectively over time.

Arginine does not show the same track record. A 2025 study in elite taekwondo athletes found that nitrate and L-arginine intake showed no significant improvements in aerobic and anaerobic performance. These findings highlight arginine’s limitations in real competition settings.

Dialing In Your L-Citrulline Dose

Most athletes do well with 3–6 g of pure L-citrulline per day. Effective dosages range from 3–6 g daily, with most performance benefits at 3–6 g daily. This range supports nitric oxide production while keeping digestion comfortable for most users.

Citrulline malate needs a slightly higher dose because of the added malate. The standard target is 6–8 g of citrulline malate in a 2:1 ratio, which gives about 3.4–4.5 g of actual citrulline. Doses of 6 g or more per day show significant benefits for blood pressure and performance.

Timing matters for your workout window. Take L-citrulline approximately 60 minutes before exercise for optimal effects. This window gives your body time to absorb citrulline, convert it to arginine, and ramp up nitric oxide before you start training.

Bodyweight can guide dosing as well. Athletes around 150–200 pounds often respond well to 6–8 g of citrulline malate. Those over 200 pounds may prefer 8–10 g. Start on the lower end, see how your body responds, then adjust for the pump and performance you want.

Stacking Arginine and Citrulline: Is It Worth It?

Most evidence suggests stacking arginine with citrulline offers little extra benefit. Combination of NO₃⁻ and L-arginine did not increase plasma NO metabolites or improve exercise performance in elite athletes, indicating limited synergy. Since citrulline already raises arginine levels so effectively, extra arginine usually adds cost and potential GI issues without clear upside.

Advanced athletes often see better results stacking citrulline with other nitric oxide and absorption enhancers. Ingredients like Nitrosigine® and Astragin® pair well with citrulline. Bucked Up’s Mother Bucker formula follows this strategy, combining 4 g pure L-citrulline with Nitrosigine® for stronger blood flow through multiple pathways.

Bucked Up promotes clinical dosing of science-backed ingredients, including Citrulline Malate and Pure L-Citrulline. Choose the setup that matches your training intensity and goals.

Citrulline and Arginine Safety Profile

L-citrulline generally shows a cleaner safety profile than arginine. Most athletes handle 6–8 g of citrulline malate with no major issues. Anyone with naturally low blood pressure should pay attention to how they feel, since vasodilation can cause lightheadedness in some people. Those on blood pressure medications should speak with a healthcare professional before starting any nitric oxide supplement.

Choosing Bucked Up Formulas for Citrulline Support

Bucked Up’s citrulline-based pre-workouts give you clinically dosed nitric oxide support in different stimulant ranges. Bucked Up Pre-Workout delivers 6 g of citrulline malate in a 2:1 ratio with 200 mg caffeine. This setup suits athletes who want a strong pump, steady energy, and extra support for the Krebs cycle from malate.

Woke AF targets high-stimulant users while keeping the same 6 g citrulline malate dose. It includes 333 mg caffeine, which can constrict blood vessels, so the citrulline helps maintain blood flow and nutrient delivery. Astragin® in the formula supports better absorption, helping you get more from every gram.

Mother Bucker caters to advanced athletes chasing maximum pumps. It features 4 g pure L-citrulline stacked with Nitrosigine® and Hydroprime® glycerol. This combination supports vasodilation and cell hydration through several mechanisms. The 400 mg caffeine blend delivers strong, sustained energy while the pump ingredients keep blood flow high.

Customer feedback often centers on the pump and performance feel. One user reports, “I have been using Bucked Up preworkout for years. About half way through my workout it kicks in, and the workout feels like it has gone to the next level. Great pump, tingling sensation and ability to push harder.” Bucked Up formulas avoid underdosed proprietary blends and instead list clinical doses that match current research.

Bucked Up promotes clinical dosing of science-backed ingredients, including Citrulline Malate and Pure L-Citrulline. Pick the formula that lines up with your stimulant preference and training goals.

Frequently Asked Questions

Which is better for muscle pumps: L-citrulline or L-arginine?

L-citrulline delivers better muscle pumps than L-arginine for most athletes. Its higher bioavailability and steady nitric oxide production keep blood flow elevated longer. Arginine breaks down heavily in the liver, while citrulline bypasses that step and raises plasma arginine more effectively. The result is a fuller, longer-lasting pump instead of the short spikes often seen with arginine.

Can I take citrulline malate and pure L-citrulline together?

Many advanced athletes combine citrulline malate and pure L-citrulline for broader benefits. Citrulline malate supports energy production through malic acid, and pure L-citrulline focuses on nitric oxide. A common approach uses 3–4 g pure L-citrulline with 6 g citrulline malate. Start with lower amounts, see how you respond, then build toward full clinical doses if needed.

How long does it take for L-citrulline to work?

L-citrulline usually reaches peak levels in your blood within about 0.7 to 2 hours after you take it. For training, a 60-minute pre-workout window works well for most people. Many athletes feel stronger pumps within 30–45 minutes, with peak effects during the first hour of exercise.

Should I take L-citrulline on rest days?

Daily L-citrulline can support recovery and cardiovascular health, even on rest days. Better blood flow helps deliver nutrients to muscles while they repair. A daily intake of 3–6 g on off days can help maintain nitric oxide levels and support ongoing recovery between hard sessions.

Is L-citrulline safe for beginners?

L-citrulline is generally beginner friendly at recommended doses. New users can start with 3 g of pure L-citrulline or about 6 g of citrulline malate. This level usually provides noticeable pumps without the jitters or crash that come with heavy stimulants. Most people tolerate citrulline well, which makes it a solid first step into pre-workout supplementation.

Final Verdict: Why Citrulline Should Be Your Go-To

Current research strongly favors L-citrulline over L-arginine for performance. Citrulline offers better bioavailability, steadier nitric oxide production, and measurable outcomes such as up to 53% more reps and 12% better endurance in key studies. It has become the standard amino acid for pump and performance formulas. Bucked Up’s clinical dosing strategies help you tap into these benefits, whether you choose a 6 g citrulline malate base or advanced stacks that add pure L-citrulline and Nitrosigine®. Choose Bucked Up’s clinically dosed L-Citrulline to upgrade pumps, endurance, and recovery in every training session.