L-Citrulline / Beetroot
L-Citrulline and Dietary Nitrate (Nitric-Oxide Pathway)
Evidence grade 3 of 5, Mixed. Read how the Atlas grades evidence.
The written rationale for this grade is still being prepared.
- FDA
- Not FDA-approved for testosterone; dietary supplements / foods
Reference only. Not medical advice.
What can go wrong
Generally safe; GI upset and mild blood-pressure lowering are the main effects, so caution is warranted with antihypertensives, nitrates, or PDE5 inhibitors. Beetroot can harmlessly turn urine and stool reddish (beeturia).
This is something to take to a clinician. The Atlas can tell you what is known about l-citrulline / beetroot in general. It cannot tell you what is happening in your body, and the difference matters most for exactly the symptoms that bring people to this page.
L-citrulline (an arginine precursor) and dietary nitrate from beetroot both raise nitric-oxide availability, improving vasodilation and exercise blood flow. A small RCT (Cormio et al., Urology, 2011) found L-citrulline improved mild erectile hardness versus placebo. These compounds belong to the erectile/performance toolkit, not the testosterone toolkit: they do not raise testosterone.
Real blood-flow and erection data; no real testosterone data.
What people take it for
These are the reasons people give for taking it. They are not effects it has been shown to have.
Combinations named above are how people use these compounds together, under names the community gave them. The combinations themselves have not been studied. Evidence for one compound is not evidence for a pair.
How it is supposed to work
L-citrulline is converted to L-arginine in the kidney, feeding nitric-oxide synthase and raising plasma arginine more effectively than oral arginine itself. Dietary nitrate from beetroot is reduced by oral bacteria to nitrite and then nitric oxide. The downstream effect is smooth-muscle vasodilation, which aids erections and exercise, not steroidogenesis.
What people get wrong
Often saidNitric-oxide boosters raise testosterone
ActuallyThey improve blood flow and erections; there is no evidence they raise testosterone.
Often saidL-arginine pills are the best NO source
ActuallyOral arginine is largely degraded before use; L-citrulline raises plasma arginine more reliably.
Who profits, and who pushes back
Nobody is named here yet, because we have not done that work on this entry. Read that as unfinished. Somebody almost certainly sells this, and somebody almost certainly disputes it. Assume both until we have checked.
What we do not know
- Can citrulline meaningfully augment PDE5 inhibitors for ED?
- What dose and timing of dietary nitrate is optimal for vascular benefit?
At a glance
- L-citrulline route
- Converts to arginine then nitric oxide
- Beetroot route
- Nitrate to nitrite to nitric oxide
- Erection data
- Small positive RCT (citrulline)
- T effect
- None demonstrated
What this entry does not yet cover
What follows is unfinished work on our side, not a finding about L-Citrulline / Beetroot. A short entry is not a safe entry.
- Timeline. We have not built the dated record of research and regulatory events.
- Cost and market. We have not documented what it sells for or who sells it.
- Supply chain. We have not mapped where it is made.
- Who uses it. We have not documented the user groups.
- What could change. No forward-looking summary yet.
- How it compares. We have not set it against the alternatives.
- Children and teenagers. We have not checked what is known about younger people.
Sources
The studies below are named and described, but not linked. You cannot open them from here and check our reading against them, which means this page is our summary of the literature rather than a document you can verify. Weigh it accordingly until the links exist.
The studies that matter
Cormio et al. (L-citrulline for mild ED, RCT)2011
Improved erection hardness score vs placebo in men with mild ED
Dietary nitrate / beetroot exercise trialsvarious
Improved blood flow and exercise efficiency; no testosterone endpoint