Arginine HCl
AKA: 1119-34-2, Arginine Hydrochloride, L-ARGININE HCL, R-Gene, R-gene 10, L-Arginine, Monohydrochloride, Hydrochloride
Synthetic
Skin Conditioner
Amino Acid
Not Clean
Arginine is an essential amino acid that is physiologically active in the L-form. In mammals, arginine is formally classified as a semiessential or conditionally essential amino acid, depending on the developmental stage and health status of the individual. Infants are unable to effectively synthesize arginine, making it nutritionally essential for infants. Adults, however, are able to synthesize arginine in the urea cycle. Arginine can be considered to be a basic amino acid as the part of the side chain nearest to the backbone is long, carbon-containing and hydrophobic, whereas the end of the side chain is a complex guanidinium group. With a pKa of 12.48, the guanidinium group is positively charged in neutral, acidic and even most basic environments. Because of the conjugation between the double bond and the nitrogen lone pairs, the positive charge is delocalized. This group is able to form multiple H-bonds. L-arginine is an amino acid that has numerous functions in the body. It helps
Effective at 9.0%
Formula
C6H15ClN4O2
Mol. Weight
210.66
CAS #
1119-34-2
Form
Powder
State
Dry Powder
Functions
Skin Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
Locks in moisture
Traditional Use
L-arginine, a naturally occurring amino acid identified in the late 19th century, used in modern skincare for its role in collagen synthesis, skin hydration, and wound healing.
EWG
4
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
Not Phototoxic
medical-approval
all-shades-safe
Concentration Guide
2e-05%
18.0%
0%100%
Reported use
CIR reported use: 0.00002-18 | 0.004-0.1
Regulatory Agencies
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory1 listing →
🛡️Safety-assessed1 review →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR