| 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). |
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