Citrulline Malate During a Bulk: Is It Worth It?
During a bulk, the goal is simple: train hard, recover, and convert surplus calories into muscle rather than fat. Citrulline malate is a popular pre-workout ingredient promising more reps and a bigger pump. Our editorial team looked at whether it actually helps when muscle gain is the objective.
What Citrulline Malate Is
L-citrulline is a non-essential amino acid found in watermelon and produced in the body. It is converted to L-arginine in the kidneys, raising blood arginine levels and supporting nitric oxide production.
Citrulline malate combines citrulline with malic acid, an intermediate of the Krebs cycle. Common ratios are 2:1 or 1:1, so 8 grams of a 2:1 product supplies roughly 5.3 grams of citrulline.
Schwedhelm and colleagues showed that oral citrulline raises plasma arginine more effectively than an equivalent dose of arginine, because citrulline avoids breakdown by intestinal and liver arginase.
In the United States, citrulline malate is a dietary supplement and is not prohibited by WADA. It is considered safe at studied doses, with occasional mild gastrointestinal discomfort.
Why It Could Matter on a Bulk
Muscle growth is driven largely by training volume and progressive overload. A meta-analysis by Schoenfeld and colleagues found a dose-response relationship between weekly sets and hypertrophy, at least up to moderate-to-high volumes.
If a supplement allows a few extra quality reps per set, those reps could add up over months. That is the main theoretical argument for citrulline malate during a mass phase.
Reduced muscle soreness, if real, might also help lifters maintain training frequency. Bulking programs often involve high volumes that leave people sore for days.
The pump itself, a transient swelling of muscle from blood flow and fluid shifts, feels motivating but has not been shown to directly cause long-term growth.
What the Studies Show
Pérez-Guisado and Jakeman reported that 8 grams of citrulline malate taken before a bench press session increased the number of repetitions performed to failure and reduced muscle soreness at 24 and 48 hours.
Wax and colleagues found that advanced weightlifters performed more repetitions in lower-body exercises after citrulline malate. However, not all trials agree; several found no difference in strength or reps.
A meta-analysis by Trexler and colleagues concluded that citrulline supplementation produced a small but statistically significant improvement in high-intensity strength and power performance. The effect was real but modest.
Critically, no long-term trial has shown that citrulline malate increases muscle mass during a bulk compared with placebo. Benefits are inferred from acute performance.
Pros and Cons During a Mass Phase
| Factor | Pros | Cons |
|---|---|---|
| Training volume | May add a few reps per set | Effect is small and inconsistent |
| Soreness | Possible reduction | Not confirmed in all studies |
| Cost | Moderate | Effective doses are large (6–8 g) |
| Safety | Well tolerated | Mild GI upset in some |
| Muscle gain | Indirect potential | No direct long-term evidence |
Gonzalez and Trexler noted in their review that results vary with dose, ratio, training status and exercise type, making it hard to predict individual response.
Many pre-workout products are underdosed, containing only 1 to 3 grams of citrulline malate. Such amounts are unlikely to reproduce study outcomes.
Bulking itself already supplies plenty of carbohydrate and energy, which may reduce the relative impact of supplements aimed at fatigue.
How to Use It if You Choose To
- Dose: 6–8 g of citrulline malate (2:1), or 3–6 g of pure L-citrulline
- Timing: about 60 minutes before training
- Take with water; a light snack may reduce GI discomfort
- Track reps and loads to judge personal benefit after 3–4 weeks
- Prioritize total calories, protein and sleep first
Daily use on non-training days is optional. Some evidence suggests that several days of supplementation may elevate arginine availability more consistently, but this has not been shown to improve gains.
People taking nitrates, PDE5 inhibitors or blood pressure medication should consult a physician, as citrulline may lower blood pressure slightly.
If you do not notice more reps or better recovery after a month, the supplement is probably not worth the money for you.
Editorial Team Conclusions
Citrulline malate may help some lifters squeeze out a few extra reps and feel less sore, which could support training volume during a bulk.
There is no direct evidence that it increases muscle mass, and effects are small and individual.
Use a full dose of 6–8 grams before training if you want to test it, and evaluate based on your training log.
Readers might find it useful to continue with our articles on arginine versus citrulline, beta-alanine for strength athletes and how to structure a bulking diet.
References
- Pérez-Guisado J, Jakeman PM. Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. J Strength Cond Res. 2010;24(5):1215–1222.
- Wax B, Kavazis AN, Weldon K, Sperlak J. Effects of supplemental citrulline malate ingestion during repeated bouts of lower-body exercise in advanced weightlifters. J Strength Cond Res. 2015;29(3):786–792.
- Trexler ET, Persky AM, Ryan ED, et al. Acute effects of citrulline supplementation on high-intensity strength and power performance: a systematic review and meta-analysis. Sports Med. 2019;49(5):707–718.
- Gonzalez AM, Trexler ET. Effects of citrulline supplementation on exercise performance in humans: a review of the current literature. J Strength Cond Res. 2020;34(5):1480–1495.
- Schwedhelm E, Maas R, Freese R, et al. Pharmacokinetic and pharmacodynamic properties of oral L-citrulline and L-arginine: impact on nitric oxide metabolism. Br J Clin Pharmacol. 2008;65(1):51–59.
- Schoenfeld BJ, Ogborn D, Krieger JW. Dose-response relationship between weekly resistance training volume and increases in muscle mass: a systematic review and meta-analysis. J Sports Sci. 2017;35(11):1073–1082.
