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Melonex Arginine HCl: What the HCl Form Is and Where It Sits
Arginine HCl is the amino acid arginine bonded to hydrochloric acid to make a stable salt. On the Melonex label it comes third, so the labeling rule caps it at 167 mg of the 500 mg blend per capsule. The label prints no actual amount, and arginine carries real medicine cautions.
Written by the Melonex label deskUpdated · 4 min read
What does HCl mean on a label?
HCl stands for hydrochloride. It is arginine paired with hydrochloric acid, a common way to make an amino acid easy to handle in powder form.
The Melonex label prints it as "L-Arginine HCL". The arginine inside is the same amino acid as the other form on the label. Only the partner molecule differs. A salt form can change how a powder handles, how it tastes and how much of the weight is arginine. It does not turn it into a different nutrient.
Why is it capped at 167 mg?
Because it is third of three. By the labeling rule, the third name cannot be more than a third of the blend 1.
- 1L- Citrulline dl - Malate167 mg or more of the 500 mg blend
- 2L-Arginine (Alpha-Ketoglutarate dihydrate)under 250 mg of the 500 mg blend
- 3L - Arginine HCLunder 167 mg of the 500 mg blend
From the Supplement Facts panel, in label order. The label prints 500 mg for the whole Proprietary Blend and no amount for any name, so the limits shown come from the order alone. Other ingredients (hydroxypropyl methylcellulose capsule, microcrystalline cellulose, magnesium stearate) are not part of the blend.
One third of 500 mg is about 167 mg. It could be far less. The label does not print it. Part of the weight of any salt is the partner, so the arginine itself is a smaller share of whatever the true amount is.
How does it differ from the other two names?
By partner molecule and by place in the list.
| Place | Name | Label limit |
|---|---|---|
| First | L-Citrulline DL-Malate | At least 167 mg |
| Second | L-Arginine alpha-ketoglutarate | At most 250 mg |
| Third | L-Arginine HCl | At most 167 mg |
The arginine HCl page has the 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 packsWhat cautions apply?
Those of arginine in general: a recent heart attack, blood pressure medicine, nitrates, sildenafil and potassium-sparing diuretics 2.
Read the list
Compare every medicine you take to the interactions above, including over-the-counter products and other supplements.
Ask a pharmacist
Show the Supplement Facts, and say the amounts are not printed.
Start low
Take one capsule with 8 oz of water, not more than the label allows.
Never stop prescribed medicine. Call 911 for chest pain or stroke signs.
Does the HCl form change the decision?
Not much. It is the smallest slice of an undisclosed blend, and the label never says how small.
If the blend as a whole interests you, check the cautions first and confirm the guarantee terms. See the blend page for what is hidden. The guarantee asks for 30 days of continuous use, so read it before you open the first bottle.
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Order 6 bottlesPrices on the Melonex sales page, October 30, 2026 3. Two bottles are also sold for $158, plus $9.99 shipping. Check your medicines with your doctor or pharmacist before you order.
FAQ01
Melonex questions people ask
What is L-arginine HCl?
It is the amino acid arginine joined to hydrochloric acid, forming a salt. It is a common supplement form.
Is arginine HCl stronger than other arginine forms?
We found no source saying so. The label lists no amounts to compare.
How much arginine HCl is in Melonex?
Not printed. By the label order it can be at most 167 mg per capsule.
Does arginine HCl upset the stomach?
Arginine references list nausea, bloating and diarrhea as possible side effects. No data exist on this capsule.
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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