Ingredient 2 of 3
L-Arginine Alpha-Ketoglutarate (AAKG) in Melonex: Second in the Blend
L-arginine alpha-ketoglutarate, or AAKG, is the second name in the Melonex blend, so by label order it is at most 250 mg of the 500 mg. It joins arginine to a compound the body uses in energy metabolism. A 7-day trial of 12 g a day of an AAKG product did not raise nitric oxide markers or blood flow.
Written by the Melonex label deskUpdated
What is arginine alpha-ketoglutarate?
AAKG is L-arginine bound to alpha-ketoglutarate, a compound the body makes in the Krebs cycle of energy metabolism. The label spells it as a dihydrate.
| Name on the label | L-Arginine (Alpha-Ketoglutarate dihydrate) |
|---|---|
| What it is | Amino acid arginine joined to alpha-ketoglutarate (a salt) |
| Place in the blend list | 2 of 3, most to least by weight |
| Amount per capsule | not printed; the label order caps it at 250 mg of the 500 mg blend |
| Amount used in research | 4 g per dose, 12 g a day, in one sports trial of 35 men |
| Strength of evidence | Little human evidence; one review says clinical evidence is lacking |
| Marketed or traditional use | Sold for exercise and blood flow |
| Main caution | No authoritative safety page for alpha-ketoglutarate was found. Arginine cautions apply: blood-pressure medicines, nitrates, recent heart attack. |
Arginine is an amino acid the body uses to make nitric oxide, a gas molecule that signals blood vessels to widen 7. Alpha-ketoglutarate is the partner, and a 2026 review notes that much of the evidence for it comes from model organisms and that oral forms combined with calcium and arginine have drawn attention 3. Sports brands sell AAKG with the idea that it delivers arginine plus an energy compound.
Where is it in the Melonex blend?
It is second in the list. The order caps it at 250 mg of the 500 mg, and the real figure is not printed.
The cap follows from the rule that names run from most to least by weight 8. Part of the weight is the alpha-ketoglutarate partner, so the arginine inside this line is less than the line itself. See the proprietary blend page for the order math.
What did studies of AAKG find?
The two best-known studies were small and in men; neither was a heart-health trial.
| Study | Who and what | Finding |
|---|---|---|
| Pharmacokinetic and 8-week study | Men aged 30 to 50; 4 g doses in the first study | Looked at blood levels, safety and exercise; see the paper for the exact outcomes 1 |
| 7-day study | 24 active men, 12 g a day or placebo | Plasma arginine rose; NOx, blood flow and related markers did not 2 |
The 7-day trial is the one closest to the nitric oxide idea, and it did not support it. That does not prove that AAKG never works. It shows the claim needs more than the chemistry.
How does the label dose compare with study doses?
The studies used 4 g and 12 g a day. A Melonex capsule holds at most 250 mg of AAKG, by label order.
That is about one sixteenth of the 4 g dose and one forty-eighth of the 12 g dose, even at the ceiling. So study results do not carry over to a capsule.
What do reviews of arginine say?
NCCIH says some research suggests oral arginine may lower blood pressure, and that evidence is mixed and limited. Memorial Sloan Kettering and others say the same.
A meta-analysis of 22 randomized trials found a pooled systolic drop of 6.40 mm Hg, but with doses of grams a day 10. A 2006 trial of 153 people after a first heart attack was stopped when more people on arginine died, which is why heart-attack patients are told not to take it without a cardiologist 11. Those facts come from other products. Read the benefits page.
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See packsHow do you read arginine AKG on the whole label?
Read it as one line out of three, under a total of 500 mg, with a plain rule about order and no promise about amount.
The label gives three facts: the name, its place and the total. It leaves out the milligrams of this line, the source of the ingredient, and any lab result. The brand's claims on the front, Heart Support* and Circulation Support*, are starred to the FDA statement that the claims are not evaluated and that the product is not meant to treat, cure or prevent any disease 12.
That matters because it is easy to move from "AAKG delivers arginine" to "so the capsule does this for me". The chain has missing links: the amount, the form, the person and the length of use. A published trial answers a question about its own capsule, its own dose and its own volunteers.
What should you ask before you buy?
Ask for the amount, the lot's lab report and the maker's name, and ask your pharmacist about your own medicines.
- What is the milligram amount of this line in my lot?
- Is there a certificate of analysis I can read, and who issued it?
- Is the facility named anywhere, or only called FDA registered?
- Does this fit with the medicines I take now?
Contact details sit on the contact page. Pharmacists check interactions for free in most pharmacies, and it takes a few minutes 13. Our testing and quality page shows which proofs the brand shows and which it does not.
If you decide to try the product anyway, write down the start date, take the label dose, and keep your home blood-pressure log, as described on the home reading page. That log helps your clinician more than any capsule can.
Is AAKG safe?
Short trials in healthy men reported it was tolerated, but long-term data are missing. People with heart or kidney conditions need advice first.
Check with a pharmacist if you take blood-pressure medicine, nitrates, sildenafil-type medicine, blood thinners, diabetes medicine or a potassium-sparing diuretic 45. See the side effects page.
FAQ01
Melonex questions people ask
What is AAKG?
It is L-arginine bound to alpha-ketoglutarate. Sports supplements often use it; the Melonex label lists it second in the blend.
How much AAKG is in Melonex?
At most 250 mg of the 500 mg blend, by label order. The real amount is not printed.
Is AAKG the same as L-arginine?
It contains arginine, but it is a different compound, because the alpha-ketoglutarate adds weight. The arginine inside is less than the listed weight.
Does AAKG raise nitric oxide?
A 7-day trial of 12 g a day in active men did not show a rise in nitric oxide markers or blood flow, though plasma arginine rose.
Is AAKG safe with blood-pressure medicine?
Ask a pharmacist first. Arginine can add to the effect of blood-pressure medicines, and the combination can lower pressure too far.
Why does the label say dihydrate?
Dihydrate means the compound holds two water molecules in its crystal. It is a chemistry detail that affects weight slightly.
Who wrote this02
Written and reviewed by
Pages built from the label, the sales page and linked NIH, FDA, CDC, FTC and peer-reviewed sources.
Last updated . Read our editorial standards and how we check reviews. This website is the information site for a USA Authorized Melonex Retailer. It is not the manufacturer or the distributor named on the label. We earn money when you buy through our order links.
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