Ingredient 3 of 3
L-Arginine HCl in Melonex: What an Arginine Hydrochloride Supplement Can Hold at 167 mg
L-arginine HCl is the third name in the Melonex proprietary blend. Label order caps it at 167 mg per capsule, as a salt, so the arginine itself is less. Studies of arginine alone mostly used several grams a day. Mayo Clinic, MSK and Cleveland Clinic advise against arginine after a heart attack.
Written by the Melonex label deskUpdated
The third name01
What is L-arginine HCl in an arginine hydrochloride supplement?
L-arginine HCl is the amino acid arginine paired with hydrochloride, which makes a salt that dissolves well. It is the last of the three names in the Melonex blend.
The label prints it as "L - Arginine HCL". Arginine is an amino acid the body makes and also gets from meat, fish and nuts (Cleveland Clinic, L-arginine). The chloride half adds weight, so a gram of the salt holds less than a gram of arginine.
The body makes its own nitric oxide, which helps keep vessels open (Cleveland Clinic, Endothelial Dysfunction). The idea behind arginine products is that arginine feeds related pathways. That is not a finding about Melonex.
A second arginine form is in the same capsule; see the arginine AKG page.
Quick profile02
What does the label say about Melonex L-arginine?
The label lists L-arginine HCl last inside one 500 mg proprietary blend and prints no amount.
Federal rules let a company show one blend weight and leave out the parts (21 CFR 101.36, Supplement Facts). Melonex does that.
| Name on the label | L - Arginine HCL |
|---|---|
| What it is | Amino acid arginine as its hydrochloride salt |
| Place in the blend list | 3 of 3, most to least by weight |
| Amount per capsule | not printed; the label order caps it at 167 mg of the 500 mg blend |
| Amount used in research | Pooled trials of L-arginine alone mostly used grams a day; no further change above 9 g a day |
| Strength of evidence | Small average drops in pooled trials of arginine alone; Mayo says it might help, MSK calls the evidence mixed and limited |
| Marketed or traditional use | Sold for blood-vessel support |
| Main caution | Not recommended after a recent heart attack (Mayo, MSK, Cleveland Clinic). Can add to blood-pressure medicines; Mayo also names nitrates, sildenafil and potassium-sparing diuretics. |
The panel is typed out on the supplement facts page.
Label math03
What amount of L-arginine HCl does one Melonex capsule hold?
The label does not say. Label order caps L-arginine HCl at 167 mg per capsule, about a third of the blend.
Worked example: names in a blend run from heaviest to lightest, and the blend number is their total (21 CFR 101.36, Supplement Facts). The third name cannot outweigh the first two. If all three were equal, each would be 500 divided by 3, or about 167 mg.
The two arginine names together are capped too: the first name takes at least 167 mg, leaving at most 333 mg for both.
500 mgone Proprietary Blend per capsule, amounts of the three names not printed
Proprietary Blend 500 mg- L-Citrulline DL-Malate167 to 500 mg
- L-Arginine alpha-ketoglutarateup to 250 mg
- L-Arginine HClup to 167 mg
Bars show the widest range the label order allows for each name (21 CFR 101.36, Supplement Facts). The real split is not printed.
That is salt weight, so the arginine is less. These are limits, not measurements.
Amounts vs research04
Is the arginine in Melonex close to the amounts studied?
No. Studies of arginine alone mostly used several grams a day, and the L-arginine HCl in Melonex is at most 167 mg per capsule.
A pooled analysis of 22 trials found small average blood pressure drops from arginine given by itself, and no further change above 9 g a day (Shiraseb 2022, arginine and BP).
| One capsule, ceiling | 167 mg of L-arginine HCl |
|---|---|
| Two capsules, ceiling | 334 mg a day |
| 3 g a day (3,000 mg) | About 18 times the one-capsule ceiling |
| 9 g a day (9,000 mg) | About 27 times the two-capsule ceiling |
That is arithmetic, not a verdict. No study tested Melonex.
Evidence05
What does research say about L-arginine for blood pressure?
The evidence is mixed and limited. Small average drops appear in pooled trials of arginine alone, at grams a day (Shiraseb 2022, arginine and BP).
It put systolic about 6.40 mm Hg lower and diastolic about 2.64 lower on average. Averages hide wide differences between people.
Mayo Clinic
Says arginine might help with blood pressure and is generally safe by mouth (Mayo Clinic, L-arginine).
MSK
Calls the evidence mixed and limited. One meta-analysis found no benefit on heart markers except perhaps in select patients (MSK, Arginine).
NCCIH
No dietary supplement has been shown to work like blood pressure drugs (NCCIH, Hypertension).
Only a cuff or clinic reading shows where you stand (NHLBI, What Is High Blood Pressure).
Melonex: from $49 a bottle60 capsules · 2, 3 or 6 bottles · free US shipping on 3 and 6 · 60-day money-back guarantee
See packsSafety06
Who should avoid L-arginine HCl?
Anyone who has had a recent heart attack should avoid arginine, according to Mayo Clinic, MSK and Cleveland Clinic (Mayo Clinic, L-arginine) (MSK, Arginine) (Cleveland Clinic, L-arginine).
In the VINTAGE MI trial, 6 of about 70 patients given arginine after a heart attack died, against none on placebo, and enrollment stopped (JAMA 2006, VINTAGE MI trial). The dose was about 9 g a day, far above this blend.
Possible side effects include nausea, abdominal pain, diarrhea and bloating (Mayo Clinic, L-arginine) (MSK, Arginine).
| Medicine | Named by |
|---|---|
| Blood pressure medicines | Mayo, MSK, Cleveland Clinic |
| Nitrates | Mayo, Cleveland Clinic |
| Sildenafil-type medicines | Mayo only |
| Potassium-sparing diuretics, blood thinners, diabetes medicines | Mayo only |
Never stop or change a prescribed medicine for a supplement (AHA, Managing BP Medications). Chest pain, trouble breathing or fainting means call 911 (AHA, Warning Signs of a Heart Attack).
Check yourself07
Is Melonex arginine right for me?
That depends on your medicines and history. Answer a few questions, then ask your doctor or pharmacist.
A checklist, not medical advice. See side effects.
Weighing it up08
Is Melonex a good way to get L-arginine?
Not if you want a known, studied amount. The arginine in Melonex is capped by label order and the true figure is not printed.
What you get is a one-capsule routine, a 60-day bottle and a described 60-day money-back guarantee, which you should confirm at checkout (Melonex sales page).
Two bottles are $158 plus $9.99 shipping. See the pricing page.
Keep reading09
Where do I read about the other Melonex ingredients?
The first name is citrulline malate, and the second is arginine AKG. The proprietary blend page shows how all three share 500 mg.
FAQ10
L-arginine HCl in Melonex: questions
What is the difference between L-arginine and L-arginine HCl?
L-arginine is the amino acid alone. L-arginine HCl is the same amino acid bonded to hydrochloride to form a salt. The chloride adds weight, so a gram of the salt holds less than a gram of arginine.
How many mg of L-arginine HCl are in Melonex?
The label does not print it. By label order, L-arginine HCl is at most 167 mg of the 500 mg blend per capsule, as salt weight. The arginine part is less than that.
How much L-arginine do studies use per day?
A 22-trial analysis found most studies used several grams a day, with no further change above 9 g. Melonex allows at most 334 mg of L-arginine HCl across two capsules.
Can you take L-arginine HCl after a heart attack?
Mayo Clinic, MSK and Cleveland Clinic all advise against arginine after a recent heart attack. In the VINTAGE MI trial, 6 of about 70 arginine patients died versus none on placebo. Ask your cardiologist before using Melonex.
Does arginine hydrochloride interact with blood pressure medicine?
It can. Mayo Clinic, MSK and Cleveland Clinic say arginine may add to blood pressure medicines. Mayo also names nitrates, sildenafil and potassium-sparing diuretics. Ask your pharmacist.
Is the arginine in Melonex enough to matter?
We cannot say. Amounts are hidden, and label order caps both arginine names together at 333 mg per capsule. Trials used grams, and none tested this blend.
Who wrote this11
Written and reviewed by
Pages built from the label, the sales page and linked NIH, FDA, CDC, FTC and peer-reviewed sources.
Last updated . See our editorial standards and how we check reviews. This website is the information site for the Official U.S. Melonex shop. It is not the manufacturer or the distributor named on the label. We make money when you buy through our order links.
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