Citrulline Malate Supplementation for Powerlifters

Citrulline malate is a supplement used to increase strength and endurance. The main benefit of citrulline malate is an increase in nitric oxide levels, which can improve blood flow to muscles. How does it benefit powerlifters?

Citrulline malate contains L-citrulline bonded with malic acid. 

L-Citrulline is an amino acid which gets converted by the body into L-arginine. Arginine is converted into nitric oxide. Nitric oxide promotes the relaxation and opening of blood vessels which increases blood and oxygen flow through the body. 

Citrulline malate enhances creatine phosphate regeneration – meaning quicker recovery between sets. Research doesn’t appear to support that this happens for L-citrulline alone, so this aspect is attributed to the malic acid. 

The reason why citrulline malate is used instead of arginine supplementation is that it actually raises blood arginine levels more effectively than arginine supplementation since arginine is more poorly absorbed. Taking high enough dosages of arginine to reach appropriate levels is possible, but often leads to GI distress. 

It’s also unclear whether addingcitrulline malate into other supplements provides an additive effect.Caffeine,creatine andbeta-alanine supplementation each individually could provide benefits for lifters. 

It has been interesting watching the research evolve over the years. Up until 2016, the research was mostly promising for citrulline malate. Since then there have been some studies showing mixed results: See here, here, here, and here. 

If you look at any of those studies individually without context, it will look like citrulline malate supplementation was ineffective. When you look at it in the context of the overall body of research, there is a different conclusion. 

In general, the studies produce results that are relatively small. This is pretty normal for supplements. No sports supplements are producing massive improvements in performance across the board. 

When looking at the overall body of research, citrulline malate appears to produce improvements in line with the results that caffeine and beta-alanine produce, on average. Both of those are considered to be evidence-based supplements that consistently produce good results, so I would add citrulline malate into that category as well. 

To quote a 2019meta-analysis by Trexler et al on citrulline supplementation: “In this analysis of 12 studies, citrulline modestly improved strength endurance (based on 8 studies), while marginally enhancing power outcomes. This occurs in both trained and untrained lifters. 

An effect size of .3 for strength endurance highlights a small-modest benefit, but we should examine this effect in context. 

For comparison, creatine supplementation yields an ES of .42 for upper, and .21 for lower body strength. Meanwhile, similar supplements log effect sizes of .41 (acute caffeine), .40 (bicarbonate), .19 (nitrate), and .17 (beta-alanine) for 45 second-8 minute exercise performance. As such, citrulline malate provides effects comparable to those of other ergogenic supplements. Therefore, citrulline probably won’t make a major difference, but it might help.” 

From one perspective citrulline malate is by far the most researched form of citrulline. That alone is enough to make me prefer it. We know that it has benefits in this form, while we are less sure about how much benefit you get from L-Citrulline alone. 

There is also speculation that malic acid has independent performance benefits related to ATP production. 

Being realistic though, it does appear that most of the benefits come from the citrulline itself. But citrulline malate is relatively cheap and widely available. 

The only way I could see that citrulline malate would be inferior to L-citrulline is if the ratio of citrulline to malic acid is low, or if the total dosage is too low. It appears that a 2:1 ratio of citrulline to malate seems solid. 

Frustratingly enough though, it is worth being aware that some companies have misreported their dosages in the past (based on US data). In one study,five different products that claimed to have a 2:1 ratio actually had anywhere between a 1:1 and 1.9:1 ratio. 

To the best of my knowledge, there is nothing to indicate a lack of safety when utilised by healthy people at the effective dosages that have been studied. 

No long-term studies have been done though, so this might change in the future.

The dosage I would recommend is 8g citrulline malate (with a 2:1 ratio of citrulline to malic acid) taken 30-120 minutes prior to training. 

Peak arginine levels appear to be reached 1.4-2.3 hours after supplementation which lines up well with this recommendation. 

There isone study comparing timing which reported no difference between consumption one hour or two hours prior to training. 

And to put things in perspective since a lot of people also like a food first approach: Watermelon is one of the highest food sources of citrulline. Per 100g, watermelon contains 0.7-3.6g of citrulline. Since the ideal ratio is ~2:1 and the total dosage of citrulline malate is 8g, that means that 5.3g of citrulline is the desired dosage. It would take a minimum 200g of watermelon (and potentially a lot more) to achieve that dosage. 

Citrulline malate quite clearly improves performance when taking multiple sets to failure, by allowing additional reps to be completed. 

If your goal is to increase the number of reps completed, then it would be worthwhile taking citrulline malate. It’s relatively affordable and doesn’t have any noticeable downsides. 

From another perspective, if your goal is hypertrophy or to improve your strength for one rep max attempts, then it is questionable as to whether citrulline malate will help. Personally, as a powerlifter, I don’t use citrulline malate, but if the research starts to indicate that it will increase one rep max performance, I would definitely consider it.