Ingredient 2 of 3
L-Arginine AKG in Melonex: Alpha-Ketoglutarate, Explained
L-arginine alpha-ketoglutarate, or AAKG, is the second of three lines in the Melonex 500 mg blend, so one capsule holds at most 250 mg of it. In studies, 3,000 mg of AAKG did not improve strength, and a week of an AAKG product did not raise blood flow. No trial has tested Melonex.
Written by the Melonex numbers deskUpdated
01What it is
What is L-arginine alpha-ketoglutarate (AAKG)?
L-arginine alpha-ketoglutarate, written AAKG or arginine AKG, is the amino acid L-arginine paired with alpha-ketoglutarate.
Alpha-ketoglutarate is a Krebs-cycle compound. On the Melonex label it reads "L-Arginine (Alpha-Ketoglutarate dihydrate)". Sports products sell AAKG for "nitric oxide" and workouts.
It is second in the blend. Weight order means it can hold at most half of the 500 mg, so the ceiling is 250 mg per capsule (21 CFR 101.36 (proprietary blends)).
| Name on the label | L-Arginine (Alpha-Ketoglutarate dihydrate) |
|---|---|
| What it is | L-arginine paired with alpha-ketoglutarate, a Krebs-cycle compound (AAKG) |
| Place on the label | 2 of 3 in the 500 mg proprietary blend |
| Most per capsule | 250 mg (ceiling; real amount not printed) |
| At 2 capsules | at most 500 mg |
| Amount used in research | 3 g of AAKG before exercise (no benefit); 4-24 g a day of L-arginine in blood-pressure trials |
| What research found | No blood-flow or performance benefit in AAKG studies |
| Main caution | Not after a recent heart attack; may add to blood-pressure drugs, nitrates and sildenafil. |
02How much
How much arginine AKG is in one Melonex capsule?
At most 250 mg per capsule, or 500 mg at two capsules. The label prints no single amount.
An even split would give about 167 mg. The two arginine lines together cannot pass 333 mg, because the citrulline line must weigh at least as much as either of them. Those weights include the AKG part, so the arginine itself weighs less.
| 1 capsule | 2 capsules | |
|---|---|---|
| AAKG line, at most | 250 mg | 500 mg |
| Both arginine lines, at most | 333 mg | 667 mg |
03The studies
Does arginine AKG improve blood flow?
In the AAKG studies found here, no. A week of an AAKG product did not raise blood flow in 24 men.
The Baylor study had the men take an AAKG product for seven days. Blood flow after resistance exercise matched placebo, and exercise itself raised it (Baylor University, AAKG and blood flow). A second trial gave 16 men 3,000 mg of AAKG 45 minutes before lifting. One-rep max and total load did not change (J Int Soc Sports Nutr 2012, AAKG).
NIH adds that arginine at 2-20 g a day typically had no effect on nitric oxide or blood flow in exercise studies (NIH ODS, Supplements for Exercise). These were exercise studies in healthy men, not people with blood-pressure problems.
L-citrulline DL-malate
≤500 mgplace 1 of 3One capsule's ceiling is 17% of the low end of the studied dose. (Avicenna J Phytomed 2019, L-citrulline and BP meta-analysis)
Both arginine lines together
≤333 mglines 2 and 3 togetherOne capsule's ceiling is 8% of the low end of the studied dose. (Am Heart J 2011, L-arginine and BP meta-analysis)
L-arginine AKG
≤250 mgplace 2 of 3One capsule's ceiling is 8% of the low end of the studied dose. (J Int Soc Sports Nutr 2012, AAKG)
Coral bars: the most one capsule (and the 2-capsule label maximum) can hold, from the label order (21 CFR 101.36 (proprietary blends)). Real amounts are not printed and are likely lower. Teal bars: daily amounts used in studies; the pale extension shows a range. The weights on the label include the malate, alpha-ketoglutarate and HCl parts, so the pure amino acid is less again.
04Blood pressure
What do blood pressure trials say about arginine?
In 11 small trials with 387 people, L-arginine at 4-24 g a day was linked to about 5 mm Hg lower systolic pressure.
Diastolic pressure fell about 2.7 mm Hg (Am Heart J 2011, L-arginine and BP meta-analysis). The study used plain L-arginine, not AAKG, and doses in grams. One capsule's AAKG ceiling of 250 mg is about 6% of the 4 g low end. No trial tested Melonex.
Side effects at 9-30 g a day were stomach upset and slightly lower pressure (NIH ODS, Supplements for Exercise). Mayo Clinic lists nausea, bloating and diarrhea, and says do not combine arginine with potassium-sparing diuretics (Mayo Clinic, L-arginine).
05Safety
Who should avoid arginine?
Anyone with a recent heart attack. A trial of 9 g a day of arginine after a heart attack was stopped early.
That was 6 deaths (8.6%) against none (ACC, VINTAGE MI trial summary). The dose was grams, far above one capsule, but the advice stands: not after a recent heart attack. More on L-arginine HCl. Keep taking prescribed medicine as directed.
06FAQ
Arginine AKG questions
What is AAKG?
AAKG is arginine alpha-ketoglutarate, the amino acid L-arginine paired with a Krebs-cycle compound. It is sold in sports products for workouts and "nitric oxide". Melonex lists it as the second line of its 500 mg blend.
How much arginine AKG is in Melonex?
At most 250 mg per capsule, because it sits second in a 500 mg blend listed by weight (21 CFR 101.36 (proprietary blends)). At two capsules the ceiling is 500 mg. The label prints no single amount, so the real figure may be lower.
Does arginine AKG increase blood flow?
Not in the studies found here. A week of an AAKG product did not raise blood flow in 24 men (Baylor University, AAKG and blood flow). NIH also reports typically no effect of arginine on nitric oxide or blood flow in exercise studies (NIH ODS, Supplements for Exercise).
Does AAKG build muscle or strength?
One trial found no gain. In 16 men, 3,000 mg of AAKG before lifting did not change one-rep max or total load (J Int Soc Sports Nutr 2012, AAKG). One capsule of Melonex holds at most 250 mg of it.
Is arginine AKG safe with blood pressure medicine?
Ask first. Arginine can add to blood-pressure drugs, nitrates and sildenafil, and pressure may drop too low (Mayo Clinic, L-arginine). Keep taking prescribed medicine as directed, and show the bottle to your pharmacist.
Is arginine AKG safe after a heart attack?
No. Mayo Clinic does not recommend L-arginine after a recent heart attack (Mayo Clinic, L-arginine). In one trial, 6 of 153 patients on 9 g a day died, and none on placebo (ACC, VINTAGE MI trial summary). Ask your cardiologist.
07Who wrote this
Written and reviewed by
Pages built from the label, the seller's materials and linked NIH, FDA, CDC, AHA, FTC and peer-reviewed sources.
Last updated . Read how we write and how we check reviews. This website is run by Melonexheart, which describes itself as a U.S. authorized Melonex merchant. It is not the manufacturer or the label's distributor, and we cannot independently verify the 'authorized' status. We are paid when you buy through our order links.
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