Hexapeptide-33 Basic Chemical Information

Field Name	Basic information
INCI Name	Hexapeptide-33
CAS No.	1192135-40-2
Synonyms	Hexapeptide-33; W3 peptide ; Ser-Phe-Lys-Leu-Arg-Tyr-NH2; SFKLRY
Key Benefits	Anti-pigmentation/Brightening

Hexapeptide-33 Powder Specification

Field Name	Basic information
Form	Powder
Appearance	White to off-white powder
Purity (HPLC)	≥ 95.0%, or ≥ 98.0%
Storage Conditions	Store sealed, protected from light and moisture. Long-term storage at -20°C is recommended.
Packaging	Glass/plastic sample bottles, or customized packages based on special requests.
Shipping	Express air freight with moisture-proof protection.
Inquiry	[Request a Quote / Order Samples]

Hexapeptide-33 Solution Specification

Field Name	Specification Details
Form	Liquid
Appearance	Clear Transparent Liquid
Peptide Content	500ppm – 1000ppm (Customizable)
Storage Conditions	Can transport at room temperature. Store in a dry, dark place at 2-8°C for long term storage.
Packaging	1Kg or 5kg, or customized packages based on special requests.
Inquiry	[Request a Quote / Order Samples]

Hexapeptide-33 intercepts melanin triggers via GPCR antagonism, inhibits tyrosinase, and prevents PIH for high-precision skin brightening.

Advantage and Benefit

Feature	Details
Signal Interception	Acts as a GPCR antagonist to block α-MSH, the primary “start” signal for melanin production.
Tyrosinase Inhibition	Directly reduces tyrosinase activity to prevent the conversion of DOPA into melanin.
PIH Prevention	Highly effective in calming the stress signals that lead to post-inflammatory hyperpigmentation.
Precision Brightening	Targets localized dark spots and uneven skin tone with surgical precision at a molecular level.
Safety Profile	Non-cytotoxic whitening approach that brightens the skin without damaging melanocyte health.

FAQs

Q1:What is the mechanism by which Hexapeptide-33 (SFKLRY-NH₂) delivers anti-pigmentation benefits for facial skin, and what in vitro evidence supports this?

A:Hexapeptide-33 (sequence Ser‑Phe‑Lys‑Leu‑Arg‑Tyr‑NH₂) inhibits melanin synthesis through two complementary pathways. It acts as a direct tyrosinase inhibitor, reducing melanin formation in B16 melanoma cells. Additionally, it functions as an endothelin‑1 receptor antagonist, blocking ET‑1 signaling that stimulates melanogenesis. In vitro, it reduces melanin production by over 40% and decreases tyrosinase protein levels in B16 cells. A 2009 study (Lee et al., Int J Pept Res Ther 15:281–286) first reported these anti‑melanogenic and antioxidant properties for this peptide.

Q2:How does Hexapeptide-33 inhibit melanin without the harshness of traditional acids?

A: Unlike AHAs or Vitamin C which can be irritating, Hexapeptide-33 is a Biomimetic Signal Blocker. It targets GPCRs (G-Protein-Coupled Receptors) on melanocytes to interrupt the “tanning command.” By blocking the signaling cascade that leads to melanin synthesis, it achieves a powerful brightening effect while remaining completely soothing and safe for sensitive skin.

Q3: Does it target Post-Inflammatory Hyperpigmentation (PIH)?

A: This is where Hexapeptide-33 truly shines. Because of its “Wound-repair” heritage, it is exceptionally effective at preventing and fading PIH (dark spots left by acne or procedures). It calms the inflammatory signals that usually trigger melanocytes to overproduce pigment, ensuring that repaired skin heals with a clear, even tone.

Q4: Can Hexapeptide-33 address existing dark spots and uneven skin tone?

A: Yes. By consistently inhibiting new melanin production and promoting healthy keratinocyte turnover, it prevents existing spots from darkening while allowing the skin to naturally shed pigmented cells. This leads to a visible “global brightening” effect and a more radiant, uniform complexion.

Q5: Is it compatible with other whitening actives like Niacinamide or Tranexamic Acid?

A: It is a perfect synergy partner. While Niacinamide blocks melanin transfer and Tranexamic Acid targets plasmin, Hexapeptide-33 works at the earliest signaling stage. Combining them creates a multi-layered defense against hyperpigmentation, covering every step from “signal” to “stain”.

Q6: Why is it recommended for “After-Sun” or “Post-Laser” whitening?

A: UV exposure and laser treatments trigger a massive release of α-MSH (melanocyte-stimulating hormone). Hexapeptide-33 steps in as a molecular shield, neutralizing the stress signals that cause “rebound” pigmentation. It’s the ideal active for ensuring that skin stays bright after being challenged by external stressors.