What is it? L-Arginine is an amino acid with a basic pH—it’s useful for boosting the pH of our formulations.

It has moisturizing, skin conditioning, and barrier boosting properties, but if used at pH-adjusting amounts those benefits are unlikely to be noticeable in a finished product. The formulations I’ve found that use it as an active ingredient use it at 0.5–2%. Your mileage may vary, though! Depending on the formulation you may be able to work in enough L-Arginine to get skin benefits and a perfect pH.

INCI Arginine
Appearance White crystaline powder
Usage rate As needed to get the pH of your formulation where you want it; generally less than 1%.
Scent Nothing noticeable at pH-adjusting levels.
pH A 10% L-Arginine solution has a pH between 10.5–12.
Solubility L-Arginine is water-soluble.
Why do we use it in formulations? L-Arginine is used to raise the pH of our formulations; I find I’m most likely to need it when working with acid-based natural preservatives that dramatically lower the pH of a formulation.
Do you need it? No, but you should have something to raise the pH of your formulations and this L-Arginine is a good choice if you can get it.
Refined or unrefined? L-Arginine only exists as a refined ingredient.
Strengths An easy, gentle ingredient for raising the pH of our formulations.
Weaknesses It’s not terribly easy to find.
Alternatives & Substitutions A 10% NaOH (lye) solution or triethanolamine will work, but not in the same amounts—if you’re following a formulation that includes L-Arginine to adjust the pH you’ll have to test and adjust with the new base/pH raising ingredient.
How to Work with It L-Arginine isn’t super strong, so you can add the straight powder to some formulations, or make a dilution—whatever works for each formulation. I keep a 10% solution and the pure powder on hand.
Storage & Shelf Life Stored somewhere cool, dark, and dry,
Tips, Tricks, and Quirks Cosmetic grade L-Arginine is not the same as food, dietary supplement, or pharmaceutical grade. I’m unsure if L-Arginine purchased from the drug store would be a good workaround if you can’t purchase cosmetic grade L-Arginine.
Recommended starter amount 30g (1.06oz)
Where to Buy it I’ve only found cosmetic grade L-Arginine at Skin Chakra (Germany) and Essential Wholesale (USA).

Some Formulations that Use L-Arginine


Posted on

September 7, 2021