Palmitoyl Dipeptide-5 Diaminobutyroyl Hydroxythreonine

This is a palmitoylated signal peptide used as an anti-aging/firming active, typically at very low concentrations (often well below 1%), and peptides in this class are generally well tolerated in clinical use with low rates of irritation. However, as a bioactive ingredient (not an inert base material) and given variability in individual reactivity—especially in eczema-prone skin—I do not score it as completely risk-free; mild stinging or contact reactions can occur in a small subset, particularly in compromised skin barriers. Safety Notes: This lipopeptide is typically supplied as a dilute active (often in glycerin/solvent carriers) and is most commonly used in leave-on anti-aging serums/eye creams at very low use levels around 0.001–0.01% active due to cost and the potency typical of signal peptides. In the consumer market, I have observed trace inclusion down to ~0.0005% in multi-ingredient peptide blends and up to ~0.05% active in high-strength, peptide-focused leave-on formulations marketed as intensive wrinkle/firming treatments; rinse-off products, when present, generally sit at the low end because of limited contact time. No specific FDA/EU maximum applies, but practical upper bounds are driven by supplier recommended use, stability/solubility, and irritation/comfort considerations in leave-on formats.