Ingredient review
SH-Tetrapeptide-39 Acetate
INCI: SH-Tetrapeptide-39 Acetate
A lab-made peptide that may help firm skin by signaling collagen production, but human studies are limited.
In plain English
SH-Tetrapeptide-39 Acetate is a short chain of amino acids (a peptide) made in a lab. In skincare, it's added to products like serums and creams with the goal of encouraging your skin to produce more collagen, which can help reduce fine lines and improve firmness. Because it's a large molecule, it needs to be formulated carefully to reach deeper skin layers. While early research is promising, most evidence comes from lab studies rather than large human trials.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is still emerging, so marketing claims deserve extra caution.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- synthetic
- Evidence
- emerging
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
SH-Tetrapeptide-39 Acetate is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging SH-Tetrapeptide-39 Acetate.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
emergingThe ingredient may be promising, but claims should be treated more cautiously.
What it is
A synthetic tetrapeptide (four amino acids linked together) modified with an acetate group for stability. It belongs to a class of signal peptides designed to mimic natural collagen fragments and trigger skin repair responses.
How it works
The peptide is thought to bind to receptors on skin cells (fibroblasts) and signal them to produce more collagen and other structural proteins. This can help reinforce the skin's support network, leading to a firmer, more resilient appearance over time.
Pros
Gentle on skin
Low irritation and comedogenic risk make it suitable for most skin types, including sensitive skin.
Targeted collagen support
Designed to specifically signal collagen production, which is key for maintaining skin firmness and youthfulness.
Cons and cautions
Limited human evidence
Most research is in lab settings or small studies; large-scale human trials are lacking, so real-world effectiveness is not fully proven.
Requires careful formulation
As a peptide, it can be unstable and may not penetrate skin well without a proper delivery system, which affects how well it works.
Best for
- Adults looking for gentle anti-aging support
- Those with mild to moderate skin laxity or fine lines
Use caution if
- Anyone allergic to peptide ingredients
- Those expecting fast or dramatic results
Usage tips
Safety summary
Generally considered safe for topical use at typical cosmetic concentrations. No significant irritation or allergy signals have been reported in available data.
Research notes
Preclinical studies suggest collagen-stimulating activity, but peer-reviewed human trials are scarce. The evidence is emerging and promising but not yet strong.
Common label clues
- Typical concentration
- 0.001% to 0.1%
- Regulatory status
- Approved for cosmetic use in the EU, US, and other major markets. Not classified as a drug ingredient.
- Common uses
- Anti-aging serums, Firming creams, Eye treatments
- Environmental note
- Synthetic peptides are produced in labs with minimal environmental footprint compared to plant extracts, but their biodegradability is not well studied.
Good to know
- Peptides are often listed near the end of ingredient lists because they are used at very low concentrations.
- SH-Tetrapeptide-39 Acetate is a relatively new ingredient; more research is expected in the coming years.
Common questions
What is SH-Tetrapeptide-39 Acetate in beauty products?
SH-Tetrapeptide-39 Acetate is a short chain of amino acids (a peptide) made in a lab. In skincare, it's added to products like serums and creams with the goal of encouraging your skin to produce more collagen, which can help reduce fine lines and improve firmness. Because it's a large molecule, it needs to be formulated carefully to reach deeper skin layers. While early research is promising, most evidence comes from lab studies rather than large human trials.
What does SH-Tetrapeptide-39 Acetate do in a beauty product?
The peptide is thought to bind to receptors on skin cells (fibroblasts) and signal them to produce more collagen and other structural proteins. This can help reinforce the skin's support network, leading to a firmer, more resilient appearance over time.
Is SH-Tetrapeptide-39 Acetate safe for most people?
Generally considered safe for topical use at typical cosmetic concentrations. No significant irritation or allergy signals have been reported in available data.
Who should be careful with SH-Tetrapeptide-39 Acetate?
Anyone allergic to peptide ingredients Those expecting fast or dramatic results
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.