Lysine HCl
molecular structure · PubChem
AKA: L-Lysine hydrochloride, 657-27-2, L-Lysine monohydrochloride, Lysine hydrochloride, L-Lysine, Monohydrochloride, L-(+)-Lysine Monohydrochloride
Synthetic
Skin Conditioner
Hair Care
Amino Acid
Not Clean
L-lysine hydrochloride is the hydrochloride salt of L-lysine. It contains a L-lysine.
Effective at 0.35%
Formula
C6H15ClN2O2
Mol. Weight
182.65
CAS #
657-27-2, 10098-89-2, 22834-80-6
Form
Powder
State
Solid; [Merck Index] White powder; [Sigma-Aldrich MSDS]
Functions
Hair Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
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-lysine was identified as an essential amino acid in the early 20th century. Its use in skincare is a modern application developed to support collagen formation and skin barrier function.
EWG
4
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
Not Phototoxic
medical-approval
all-shades-safe
Concentration Guide
2e-05%
0.7%
0%100%
Reported use
CIR reported use: 0.0009-0.001 | 0.00002-0.7 | 0.00003-0.6
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