Researchers pooled 13 randomized trials of citrulline taken within 2 hours before exercise, covering 206 healthy, active adults. People who took citrulline rated the exercise as less hard and reported less muscle soreness a day later than those on placebo. Soreness at 72 hours and blood lactate levels were no different between groups.
Citrulline is a non-essential amino acid found mainly in watermelon. Two mechanisms interest sports researchers. It feeds the urea cycle, which clears ammonia, a waste product tied to fatigue. It also converts to arginine in the kidney, which the body uses to make nitric oxide, a compound that widens blood vessels and aids muscle repair. Earlier work pooled citrulline studies on strength and power. Nobody had pooled studies on how hard exercise feels, how sore people are afterwards, or blood lactate.
A systematic review and meta-analysis following PRISMA guidelines. The team searched PubMed, Web of Science and ClinicalTrials.gov up to April 2019. Studies had to be randomized, placebo-controlled, blinded trials in healthy people, using L-citrulline or citrulline malate within two hours before exercise, and reporting perceived exertion, muscle soreness or blood lactate. Two reviewers screened independently and graded quality with the Cochrane risk of bias tool. A random effects model was used because designs varied. Numbers shown only in graphs were extracted with WebPlotDigitizer, a manual plotting tool.
Thirteen studies with 206 participants were included. Sample sizes ran from 7 to 41. All participants were young and healthy, most in their twenties, and either recreationally active or resistance trained. Citrulline malate doses ran from 6 g to 12 g, with 8 g most common, and L-citrulline from 3 g to 6 g. Nine studies used anaerobic exercise such as bench press and chin-ups, two cycling, one running.
No publication bias was detected on Begg's or Egger's tests. Of the 13 studies, 8 reported on side effects and six found none. In one, 15 percent of participants had stomach discomfort after 8 g of citrulline malate.
The evidence base is small: 13 trials, 206 people, an average of 16 each. Heterogeneity was severe for the two positive outcomes, and the authors say the effect size should not be read too closely. Two studies were not double-blinded, and doses and timing varied. Only one study used aerobic exercise, so the authors caution against applying the result there. None of the studies had a prespecified protocol. Supplementation was limited to two hours before exercise, so nothing here speaks to longer-term use. Funding came from a Korean Ministry of Trade, Industry and Energy program on a medical device patch, unrelated to supplements. The authors declare no competing interests. The article is open access under a Creative Commons Attribution NonCommercial NoDerivatives 4.0 license.
Read this as a mixed result, not a clean positive. Two outcomes moved, perceived exertion and soreness at 24 hours, both measured by asking people how they felt. Three did not: soreness at 48 and 72 hours, and lactate. The 48-hour result only turned significant after one study was removed. The lactate finding is a clear null. Participants were young healthy people doing mostly resistance exercise, so the findings say nothing about older adults, untrained people, clinical groups or endurance sport.
That depends on the specific medication and formula. A few, like blood thinners with CurQLife or blood pressure medication with MaxiNOs, are worth a direct conversation with your doctor first. Check each formula's own FAQ section for specifics, or ask your health coach.
No, and we'd rather be upfront about it. Bacopa, the plant in BacoZest, has published human studies, though they used other bacopa extracts. OptiNOs and MaxiNOs each have human studies sponsored by their maker, Laila Nutraceuticals, which haven't been published in a journal. CurQLife's research is still early, from lab and animal studies, and we label it that way.
It depends on what you're building your routine around. BacoZest is built around bacopa, which is studied for memory.* OptiNOs supports strength and muscular endurance alongside resistance training.* MaxiNOs was studied for healthy blood vessel function.* CurQLife's research is still at the lab stage. Your health coach can help you pick a starting point.
All four are built around plant extracts. OptiNOs was reported as well tolerated in its human study, and published bacopa studies reported no serious side effects. CurQLife's safety data so far comes from lab and animal testing. Check with your doctor first if you're pregnant, nursing, on medication, or managing a health condition.
Because the patented ingredients behind our four formulas went through dedicated research, and research costs real money. A generic curcumin or bacopa supplement hasn't been tested in the form you get from us. You're paying for an ingredient with research behind it, not just a label.
Generic ingredients often haven't been studied in the specific form you're buying. Our four core formulas use patented ingredients, and we show you the research behind each one, including where it's still early.
It depends on the formula. In its study, MaxiNOs blood vessel response was higher than placebo 2 to 3 hours after the first dose.* OptiNOs and bacopa were studied over 6 and 12 weeks of daily use, so give them time. CurQLife is meant to be taken daily.
Yes. BacoZest, OptiNOs, MaxiNOs, and CurQLife are built for different goals, and none of them contain stimulants. They haven't been studied together, so ask your health coach how to fit them into your routine.
