Ingredients
What Are the Melonex Ingredients? The Full List and What Each One Is
The Melonex ingredients list has three active names in one 500 mg proprietary blend: L-citrulline DL-malate, L-arginine alpha-ketoglutarate and L-arginine HCl. Three more ingredients make the capsule: hydroxypropyl methylcellulose, microcrystalline cellulose and magnesium stearate. The label prints no amount for any of the three amino acid forms.
Written by the Melonex label deskUpdated
The list01
What is in Melonex capsules?
Melonex capsules contain one 500 mg proprietary blend of three amino acid forms, packed in a capsule made with three other ingredients.
The label lists the blend names in this order: L-Citrulline DL-Malate, L-Arginine (Alpha-Ketoglutarate dihydrate) and L-Arginine HCL. Below the panel, it lists the other ingredients: Hydroxypropyl methylcellulose (capsule), microcrystalline cellulose, magnesium stearate. No allergen statement is printed, so we do not call the capsule allergen-free.
Citrulline and arginine are amino acids, the building blocks of protein (Cleveland Clinic, Amino Acids). Each name on the label is an amino acid joined to a second part, which makes a salt. The idea behind such products is that the body uses these amino acids in pathways linked to blood vessel tone. No source we found shows that this happens with Melonex.
At a glance02
What does each Melonex ingredient do?
Each Melonex ingredient is sold for a reason, but the evidence for each is thinner than the sales copy suggests, and none was tested inside Melonex.
The table gives the label name, what it is, and what the research shows when the ingredient is given by itself.
| Label name | What it is | What research shows |
|---|---|---|
| L-Citrulline DL-Malate | Citrulline joined to malic acid | Mixed on blood pressure: a systolic drop of 4.10 mm Hg in one analysis (Barkhidarian 2019, citrulline and BP), no change in another (Mirenayat 2018, citrulline and BP). Small, low-certainty exercise effect (Wang 2026, citrulline malate and exercise). |
| L-Arginine alpha-ketoglutarate | Arginine joined to alpha-ketoglutarate | Little human evidence; a review notes clinical evidence is lacking (Devulapalli 2026, AKG review). One sports trial used 4 g per dose (Campbell 2006, L-arginine AKG trial). |
| L-Arginine HCl | Arginine as its hydrochloride salt | Pooled trials of arginine alone: systolic -6.40 and diastolic -2.64 mm Hg at grams a day (Shiraseb 2022, arginine and BP). Mayo says it might help (Mayo Clinic, L-arginine); MSK calls evidence mixed and limited (MSK, Arginine). |
These are results for each amino acid alone. No study tested this blend, so they describe the ingredients, not Melonex.
The label order03
How much of each ingredient does a Melonex capsule hold?
The label does not say how much of each Melonex ingredient is in a capsule, but the order of the names sets a ceiling and a floor.
US rules list the members of a blend in descending order by weight (21 CFR 101.36, Supplement Facts). The blend is 500 mg, so the first name weighs at least 167 mg. The second weighs at most 250 mg. The third weighs at most 167 mg.
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.
These figures describe salt forms. The actual citrulline or arginine is lower. They are limits from arithmetic, not measured amounts.
Ingredient pages04
Where can you read about each ingredient?
Each of the three active names has its own page, with the research and the cautions that go with it.
-
167to 500 mglabel order, of 500 mg01
L-Citrulline DL-Malate
#1 in the blend list: 167 mg or more
Amino acid citrulline joined to malic acid (a salt)
Evidence: Small average systolic drops in pooled trials, no effect in one analysis; small, low-certainty exercise benefitPer capsulenot printed; the label order puts it at 167 mg or more of the 500 mg blend
Studied at3 to 8 g (3,000 to 8,000 mg) a day of citrulline for 1 to 16 weeks
Watch forPossible bloating, cramping, diarrhea, sweating (Cleveland Clinic). That page lists no drug interactions; ask your pharmacist anyway.
Full profile -
up to 250mglabel order, of 500 mg02
L-Arginine AKG
#2 in the blend list: 250 mg at most
Amino acid arginine joined to alpha-ketoglutarate (a salt)
Evidence: Little human evidence; one review says clinical evidence is lackingPer capsulenot printed; the label order caps it at 250 mg of the 500 mg blend
Studied at4 g per dose, 12 g a day, in one sports trial of 35 men
Watch forNo authoritative safety page for alpha-ketoglutarate was found. Arginine cautions apply: blood-pressure medicines, nitrates, recent heart attack.
Full profile -
up to 167mglabel order, of 500 mg03
L-Arginine HCl
#3 in the blend list: 167 mg at most
Amino acid arginine as its hydrochloride salt
Evidence: Small average drops in pooled trials of arginine alone; Mayo says it might help, MSK calls the evidence mixed and limitedPer capsulenot printed; the label order caps it at 167 mg of the 500 mg blend
Studied atPooled trials of L-arginine alone mostly used grams a day; no further change above 9 g a day
Watch forNot 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.
Full profile
Melonex: from $49 a bottle60 capsules · 2, 3 or 6 bottles · free US shipping on 3 and 6 · 60-day money-back guarantee
See packsDoses05
Are the Melonex ingredients used at studied doses?
No, not as far as the label shows. Studies use grams a day, and the whole Melonex blend is 500 mg per capsule.
Cleveland Clinic summarizes citrulline studies at 3 to 8 g a day (Cleveland Clinic, L-citrulline). A 35-man sports trial gave arginine alpha-ketoglutarate at 4 g per dose, 12 g a day (Campbell 2006, L-arginine AKG trial). Arginine on its own showed no further change in blood pressure above 9 g a day (Shiraseb 2022, arginine and BP).
At two capsules the blend is 1 g in total. Splitting that three ways leaves each name far below those studies.
| Name on the label | Place | Amount printed | What the label order allows (per capsule) | Amount used in research | Evidence |
|---|---|---|---|---|---|
| L- Citrulline dl - Malate | 1 of 9 | Not printed | 167 mg or more, under 500 mg | 3 to 8 g (3,000 to 8,000 mg) a day of citrulline for 1 to 16 weeks (Barkhidarian 2019, citrulline and BP) (Mirenayat 2018, citrulline and BP) (Luo 2025, citrulline/watermelon and BP) (Cleveland Clinic, L-citrulline) (Wang 2026, citrulline malate and exercise) | Small average systolic drops in pooled trials, no effect in one analysis; small, low-certainty exercise benefit |
| L-Arginine (Alpha-Ketoglutarate dihydrate) | 2 of 9 | Not printed | under 250 mg | 4 g per dose, 12 g a day, in one sports trial of 35 men (Campbell 2006, L-arginine AKG trial) (Devulapalli 2026, AKG review) (Mayo Clinic, L-arginine) (MSK, Arginine) (Cleveland Clinic, L-arginine) | Little human evidence; one review says clinical evidence is lacking |
| L - Arginine HCL | 3 of 9 | Not printed | under 167 mg | Pooled trials of L-arginine alone mostly used grams a day; no further change above 9 g a day (Mayo Clinic, L-arginine) (MSK, Arginine) (Cleveland Clinic, L-arginine) (JAMA 2006, VINTAGE MI trial) (Shiraseb 2022, arginine and BP) | Small average drops in pooled trials of arginine alone; Mayo says it might help, MSK calls the evidence mixed and limited |
Cautions06
Who should be careful with these ingredients?
Anyone on blood-pressure medicine, and anyone who has had a heart attack, should ask a doctor before taking arginine.
Mayo Clinic, MSK and Cleveland Clinic advise against arginine after a recent heart attack (Mayo Clinic, L-arginine) (MSK, Arginine) (Cleveland Clinic, L-arginine). Keep taking prescribed medicine as directed (AHA, Managing BP Medications). Chest pain or trouble breathing means 911.
Bottom line07
Is the Melonex ingredients list enough to judge it?
No. A list of names tells you what the capsule is made from, not how much, so the list alone cannot show whether it works.
Fair points: the three amino acids are well known, and the capsule is simple. Weak points: hidden amounts, study doses in grams, and no trial of the product. The sales page describes "targeted nutritional support for heart health, healthy blood pressure, and overall cardiovascular wellness" and cites no studies (Melonex sales page).
Read the supplement facts and the proprietary blend page next. NCCIH says no dietary supplement has been shown to work like blood-pressure drugs (NCCIH, Hypertension).
Melonex: from $49 a bottle60 capsules · 2, 3 or 6 bottles · free US shipping on 3 and 6 · 60-day money-back guarantee
See packsFAQ08
Melonex ingredients questions
What is the main ingredient in Melonex?
The label lists L-Citrulline DL-Malate first, so it is the heaviest name in the blend, at least 167 mg of the 500 mg. That is a floor from label order, not a printed amount. The actual citrulline is less, because the malate adds weight.
Is Melonex made with L-citrulline or L-arginine?
Both. The blend names L-citrulline DL-malate plus two arginine forms, arginine alpha-ketoglutarate and arginine HCl. Citrulline and arginine are amino acids. The label does not print how much of each the capsule holds.
Does Melonex contain herbs or vitamins?
No herbs, vitamins or minerals appear on the Supplement Facts panel. It lists only the proprietary blend of three amino acid forms, plus capsule ingredients. The label front says Natural Formula, but names no plant.
What is alpha-ketoglutarate in a supplement?
Alpha-ketoglutarate is a compound the body makes in normal metabolism. In Melonex it is joined to arginine as a salt. A 2026 review says human clinical evidence is lacking and the ideal dosage still needs research.
Are there fillers in Melonex capsules?
The label lists microcrystalline cellulose and magnesium stearate as other ingredients, with hydroxypropyl methylcellulose as the capsule. The label does not say what each is for. We found no source on them and make no claim.
Who wrote this09
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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