Ingredient profile
L-Citrulline in VapoCept: HCl, Malate and the Gram-Sized Studies
L-citrulline is an amino acid the body converts into arginine. VapoCept's panel, as listed, has two lines: 100 mg L-citrulline HCl and 100 mg L-citrulline malate. Studies mostly used 6,000 to 8,000 mg a day and looked at exercise and blood pressure. The two lines together are at most about 3% of those doses, and no cited study tested citrulline for thinking.
Written by the VapoCept label deskUpdated
The basics01
What is L-citrulline, and what are HCl and malate?
L-citrulline is an amino acid. Your kidneys turn it into arginine, which is why the two often appear together in supplements.
HCl and malate are the "partners" attached to it. HCl means hydrochloride, a salt form. Malate is citrulline paired with malic acid. VapoCept's panel, as listed (check your bottle), has 100 mg of each. Part of each weight is the partner, so the citrulline itself is less than 200 mg.
| Name in the panel | L-Citrulline HCl |
|---|---|
| What it is | An amino acid that the body converts into arginine, here as a hydrochloride salt |
| Amount as listed | 100 mg |
| Share of the adult RDA (our arithmetic) | No RDA for this line |
| Amount used in research | 6,000 to 8,000 mg a day in exercise and blood pressure studies |
| Strength of evidence | Studied for exercise and blood vessels; small or mixed effects; no cognition trial found at 100 mg |
| Marketed or traditional use | Amino acid the body turns into arginine |
| Main caution | Usually well tolerated at studied amounts. Same blood pressure and nitrate cautions as arginine. |
| Name in the panel | L-Citrulline Malate |
|---|---|
| What it is | Citrulline paired with malic acid (malate) |
| Amount as listed | 100 mg |
| Share of the adult RDA (our arithmetic) | No RDA for this line |
| Amount used in research | 6,000 to 8,000 mg of citrulline malate in exercise studies |
| Strength of evidence | Studied for exercise repetitions; mixed; no cognition trial found at 100 mg |
| Marketed or traditional use | Citrulline with malic acid |
| Main caution | Usually well tolerated at studied amounts; some people get an upset stomach. Same cautions as citrulline. |
Label vs studies02
How much citrulline do studies use?
Mostly 6,000 to 8,000 mg a day. A review of 13 exercise trials found 8,000 mg of citrulline malate was the most common dose (Citrulline, perceived exertion and soreness meta-analysis (2020)).
The two VapoCept lines add up to 200 mg of salts. That is at most 2.5% of 8,000 mg and 3.3% of 6,000 mg. This is arithmetic from the numbers on the panel, not a verdict on your body.
| Item | Amount a day | 200 mg is at most |
|---|---|---|
| Citrulline malate in exercise trials | 8,000 mg | 2.5% |
| Dose where diastolic pressure fell | 6,000 mg or more | 3.3% |
| VapoCept, both lines together | 200 mg of salts | Not applicable |
The brand's information does not say how the two lines were chosen. We found no study of this pairing.
The proposed pathway03
Does citrulline raise nitric oxide and blood flow?
It is proposed that citrulline becomes arginine, arginine becomes nitric oxide, and nitric oxide relaxes blood vessels. That route was studied mostly in exercise and blood pressure, not in the brain.
NIH's Office of Dietary Supplements says citrulline raised blood markers of nitric oxide in some studies, but that did not line up with better performance (NIH ODS, Exercise and athletic performance (health professional)). Tap a panel line below to see the proposed route.
Pathways
200 mg + 200 mg + 100 mg + 100 mg · as listed in the brand's panel
Four of the seven lines (two arginine, two citrulline) feed the proposed nitric oxide route: arginine, or citrulline turned into arginine, is the raw material for nitric oxide, which relaxes blood vessel walls. Studies use grams a day (arginine 2,000 to 24,000 mg, citrulline 6,000 to 8,000 mg), mostly for blood pressure and exercise. The listed amounts are 100 to 200 mg.
Illustration of a proposed mechanism, studied mostly in exercise research. It is not a measured effect on mind, and it is not what happens in your body. Sources: (MSK, Arginine (About Herbs)) (Trexler 2019, Citrulline and strength/power meta-analysis) (ISSN position stand, Beta-alanine) (NIH ODS, Niacin (consumer))
What studies found04
What do citrulline studies actually show?
Small effects, in small studies, at gram doses. None of them measured memory, focus or clarity.
Strength and power
A review of 12 studies and 198 people found a small gain in high-intensity effort. The effect size was 0.20 and its interval barely cleared zero (Trexler 2019, Citrulline and strength/power meta-analysis).
Effort and soreness
In 13 trials with 206 people, rated effort and 24-hour soreness were lower (Citrulline, perceived exertion and soreness meta-analysis (2020)).
Blood pressure
Two meta-analyses found systolic pressure fell about 4 mm Hg, from few and small trials (Yang 2019, L-citrulline and blood pressure meta-analysis) (Citrulline and blood pressure meta-analysis (Avicenna J Phytomed)).
No cited study tested citrulline for thinking. We found only rat work and patents, and those are not sources. We cannot say citrulline improves memory, focus or clarity.
VapoCept: 30 capsules, 30-day bottleOne capsule a day · 2, 3 or 6 bottles · $49 to $79 a bottle per the brand information, confirm at checkout
See packsSafety05
Is L-citrulline safe, and who should ask first?
At studied amounts it is usually well tolerated. Some people get an upset stomach, and it may lower blood pressure.
Because arginine and citrulline lower blood pressure at gram doses, treat the cautions as shared with the arginine lines. Ask a doctor or pharmacist first if you take blood pressure medicine, a nitrate or a sildenafil-type medicine.
A supplement is not a drug. Keep taking prescribed medicine. Sudden confusion or trouble speaking needs a 911 call, not a capsule.
Claims06
Does the VapoCept formula have clinical proof for citrulline?
No. "Clinically studied" would mislead here, because the studies used about 30 to 40 times the amount on the panel.
The FTC says research on one ingredient does not automatically back a finished product, since dose and combination must match. The seller's front wording is "Clinical Memory Restoration", and no source we found shows it. See our research review for the full line-by-line check.
FAQ08
VapoCept questions people ask
How much L-citrulline is in VapoCept?
As listed in the brand's panel (check your bottle), one capsule has 100 mg L-citrulline HCl and 100 mg L-citrulline malate. The citrulline content is lower than 200 mg because the partner parts have weight too.
What is the difference between citrulline HCl and malate?
Both carry the same amino acid. HCl is a hydrochloride salt, and malate pairs citrulline with malic acid. Most exercise studies used the malate form at 6,000 to 8,000 mg a day.
Does citrulline improve blood flow?
Gram doses lowered systolic blood pressure by about 4 mm Hg in small meta-analyses. Nothing we found shows that 200 mg changes blood flow, and none of it measured the brain.
Does citrulline help memory or focus?
No cited study tested that. The research we found looks at exercise and blood pressure, so any memory claim for the label amount is untested.
Can citrulline interact with medicines?
It may add to blood pressure drugs, nitrates and sildenafil-type medicines. Ask your pharmacist before combining them, and keep taking your prescriptions.
Are citrulline and arginine the same?
No, but related. The body converts citrulline to arginine. VapoCept lists both, plus an arginine AKG line, and no source studied that mix together.
Sources (8)
- ArginineMemorial Sloan Kettering Cancer Center (About Herbs), 2022
- Effect of oral L-citrulline on brachial and aortic blood pressure defined by resting status: evidence from randomized controlled trialsYang HH, Li XL, Zhang WG, Figueroa A, Chen LH, Qin LQ. Nutrition & Metabolism 2019;16:89, 2019
- Effects of L-citrulline supplementation on blood pressure: A systematic review and meta-analysisBarkhidarian B, et al. Avicenna Journal of Phytomedicine (ajp.mums.ac.ir); authors and year are from general knowledge, as the fetched page showed only affiliations (Iranian universities) and a search date of November 16, 2017, 2019
- Acute Effects of Citrulline Supplementation on High-Intensity Strength and Power Performance: A Systematic Review and Meta-AnalysisTrexler ET, Persky AM, Ryan ED, Schwartz TA, Stoner L, Smith-Ryan AE. Sports Medicine 2019;49(5):707-718 (abstract via Duke Scholars), 2019
- Effect of citrulline on post-exercise rating of perceived exertion, muscle soreness, and blood lactate levels: A systematic review and meta-analysisJournal of Sport and Health Science 2020 (authors not shown on the fetched PubMed page; Rhim HC et al. from general knowledge), 2020
- International Society of Sports Nutrition position stand: beta-alanineTrexler ET, Smith-Ryan AE, Stout JR, et al. Journal of the International Society of Sports Nutrition 2015;12 (abstract via Northumbria University repository), 2015
- Dietary Supplements for Exercise and Athletic Performance: Fact Sheet for Health ProfessionalsNIH Office of Dietary Supplements, 2026
- Niacin: Fact Sheet for ConsumersNIH Office of Dietary Supplements, 2021
Who wrote this09
Written and reviewed by
Pages built from the brand information, the brand's images and linked NIH, FDA, FTC and peer-reviewed sources.
Last updated . Read our editorial standards and how we check reviews. This website is the information site of Vapocepts, the U.S. stocking partner for VapoCept. It is not the manufacturer and it is not the sales page. We earn money when you buy through our order links.
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