L-Citrulline Dosage: How Much to Take, Clinical vs Label (2026)
Take 3 to 6 g of pure L-citrulline a day, the usual range in studies of blood pressure and workouts. Trials in adults over 60 used 3 to 10 g. For a workout, trials used 6 to 8 g of citrulline malate, which is only part citrulline.
Based on published research, not medical advice. Take blood pressure medicine, nitrates or drugs for erections? Ask your doctor first.
Ready to buy:
Nutricost Pure L-Citrulline$0.33 for 6 g. It is pure citrulline, so every gram counts. Why it is our pick.
Costs are brand prices, checked October 19, 2026.
Which L-citrulline is right for you?
Other ways to get 6 g:
Get drug-tested for sport? Pick one on a banned-substance list.
Kaged L-Citrulline is on Informed Sport, which tests for substances banned in sport. A scoop is 2 g, so 3 scoops make 6 g. That costs $0.60 at the brand’s price, about 1.8 times our pick.
Kaged L-Citrulline
On Informed Sport · 2 g a scoop
Want the lowest cost per gram? Use more scoops of malate.
Its label says 2 g of citrulline per 3 g scoop, so 6 g takes 3 scoops (9 g of powder) and costs $0.31, 2 cents less than our pick.
BulkSupplements Citrulline Malate 2:1
2 g citrulline in 3 g
Hate powder? Capsules work, but you take a lot.
8 capsules give 3 g. 6 g takes 16 capsules and costs $1.53, about 5 times the powder.
BulkSupplements L-Citrulline Capsules
3 g in 8 capsules
Over 60? Start low.
Our suggestion is 3 g, then 6 g if your stomach is fine. What trials found.
Take nitrates or ED drugs? Don’t, unless your doctor says yes.
With nitrates for the heart or ED drugs (for erections) like sildenafil, blood pressure may drop too far (WebMD). We found no trial that tested these mixes. Take any blood pressure medicine? Ask your doctor first.
How much L-citrulline by goal
- Blood pressure: 3 to 9 g a day in trials. The top number fell about 4 points in a review of 8 trials and the bottom number did not fall by a clear amount (Barkhidarian 2019). Another review found no effect (Mirenayat 2018). It is not a treatment for high blood pressure.
- Workout: 6 to 8 g of malate, 40 to 60 minutes before. About 3 more reps, a small effect (Vårvik 2021).
- Erections: 1.5 g a day. Better in 12 of 24 men with mild problems, against 2 of 24 on placebo, in one small trial where everyone took the placebo first (Cormio 2011).
L-citrulline for adults over 60
Trials in older adults used 3 to 10 g a day, most often 6 or 10 g. Starting at 3 g and moving to 6 g if your stomach is fine is our suggestion, not something a trial tested. The results were small:
- Blood pressure: about 4 points lower on the top number in a review of citrulline and watermelon trials in middle-aged and older adults (Luo 2025). In women past menopause with high blood pressure, 10 g a day gave a small drop (Maharaj 2022).
- Muscle: it did not raise muscle protein building in men aged 65 to 80 after one meal (Churchward-Venne 2014), or in people aged 80 to 92 over 3 weeks, though lean mass rose in a subgroup of the women (Bouillanne 2019).
- With exercise: people over 65 doing interval training who took 10 g a day walked faster than those doing the same training with a placebo, in a secondary analysis (Buckinx 2020).
Citrulline malate: how much is citrulline?
Citrulline malate is citrulline mixed with malic acid. A true 2:1 mix is at most 72% citrulline, so 6 g of citrulline takes about 8.3 g of powder. Labels can overstate it: in a lab test of five 2:1 powders sold in the UK, an 8 g dose held 5.3 g of citrulline in the best and 4.2 g in the worst (Chappell 2018). If a label gives grams of citrulline, use that number.
Work out the citrulline in your product
How to take it
- Mix the powder in water, every day. One scoop of our pick is 3 g.
- If your stomach gets upset, split the dose in two. After 8 g of malate, about 1 in 7 men had stomach discomfort (Pérez-Guisado 2010).
Is it safe?
There is no official upper limit. In one trial, healthy men (average age about 41) took up to 24 g a day for 4 weeks with no harm found (Miura 2023). Trials in older adults used up to 10 g a day, but none were built to test safety, and no trial tested it with medicines. WebMD says not to take it if you are pregnant or breastfeeding.
Questions people ask
How much L-citrulline should I take a day?
Many studies used 3 to 6 g of pure L-citrulline a day; some used up to 10 g. There is no official daily amount. 6 g is 2 scoops of our pick.
How much citrulline is in 6,000 mg of citrulline malate?
At most about 4.3 g. In a lab test of five 2:1 powders, an 8 g dose held 5.3 g down to 4.2 g of citrulline (Chappell 2018).
Related guides
Sources
- Barkhidarian B, et al. “Effects of L-citrulline supplementation on blood pressure: A systematic review and meta-analysis.” Avicenna J Phytomed. 2019. PubMed 30788274
- Vårvik FT, et al. “Acute Effect of Citrulline Malate on Repetition Performance During Strength Training: A Systematic Review and Meta-Analysis.” Int J Sport Nutr Exerc Metab. 2021. PubMed 34010809
- Cormio L, et al. “Oral L-citrulline supplementation improves erection hardness in men with mild erectile dysfunction.” Urology. 2011. PubMed 21195829
- Luo P, et al. “Does l-citrulline supplementation and watermelon intake reduce blood pressure in middle-aged and older adults? A systematic review and meta-analysis of randomized controlled trials.” Clin Nutr ESPEN. 2025. PubMed 40789388
- Maharaj A, et al. “Effects of L-Citrulline Supplementation on Endothelial Function and Blood Pressure in Hypertensive Postmenopausal Women.” Nutrients. 2022. PubMed 36297080
- Churchward-Venne TA, et al. “Citrulline does not enhance blood flow, microvascular circulation, or myofibrillar protein synthesis in elderly men at rest or following exercise.” Am J Physiol Endocrinol Metab. 2014. PubMed 24824653
- Bouillanne O, et al. “Impact of 3-week citrulline supplementation on postprandial protein metabolism in malnourished older patients: The Ciproage randomized controlled trial.” Clin Nutr. 2019. PubMed 29503060
- Buckinx F, et al. “High intensity interval training combined with L-citrulline supplementation: Effects on physical performance in healthy older adults.” Exp Gerontol. 2020. PubMed 32721549
- Chappell AJ, et al. “Citrulline malate supplementation does not improve German Volume Training performance or reduce muscle soreness in moderately trained males and females.” J Int Soc Sports Nutr. 2018. PubMed 30097067
- Pérez-Guisado J, Jakeman PM. “Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness.” J Strength Cond Res. 2010. PubMed 20386132
- Mirenayat MS, et al. “Effect of L-Citrulline Supplementation on Blood Pressure: a Systematic Review and Meta-Analysis of Clinical Trials.” Curr Hypertens Rep. 2018. PubMed 30284051
- Miura N, et al. “Subchronic tolerance trials of graded oral supplementation with ornithine hydrochloride or citrulline in healthy adults.” Amino Acids. 2023. PubMed 36571619
- WebMD. “L-citrulline.” Medically reviewed August 14, 2025. webmd.com
- Citrulline per serving and prices from each brand’s own label and store.