Ingredient review

SH-Polypeptide-91

INCI: SH-Polypeptide-91

SH-Polypeptide-91 is a lab-made peptide that may help reduce fine lines by signaling skin cells to produce more collagen, though human studies are limited.

beautyskincareanti-aging

In plain English

SH-Polypeptide-91 is a tiny protein fragment made in a lab. When applied to skin, it acts like a messenger, telling skin cells to make more collagen and elastin. This can help plump up the skin and soften the look of fine lines over time. It's a gentle ingredient, unlikely to cause irritation, and is often found in anti-aging serums and creams.

Review score

Safety, usefulness, and evidence

4.0Good
4.0/ 5

Potentially useful with some tradeoffs

The evidence base is useful, but some claims depend heavily on the formula.

Risk flags are low for most users, though the finished product can still irritate.

Source
synthetic
Evidence
moderate
Irritation
low
Clogging risk
low
How reviews are scored

Quick decision guide

Useful, but context matters

SH-Polypeptide-91 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.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging SH-Polypeptide-91.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. 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

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

A synthetic peptide, specifically a hexapeptide (made of six amino acids), designed to mimic natural signaling molecules in the skin that stimulate collagen production.

How it works

It binds to receptors on skin cells (fibroblasts) and triggers a cascade of signals that increase the synthesis of collagen and other structural proteins. This helps reinforce the skin's support network, leading to firmer, smoother skin with continued use.

Pros

Gentle on skin

SH-Polypeptide-91 has a low irritation risk, making it suitable for sensitive skin types that may react to stronger anti-aging actives like retinol.

Supports collagen naturally

Instead of forcing collagen production, it signals your skin's own cells to produce more, which can lead to gradual, natural-looking improvements in firmness.

Cons and cautions

Subtle effects

Results are not dramatic or instant. You'll need to use it consistently for several weeks to notice a difference in fine lines and texture.

Less research than some peptides

Compared to well-known peptides like Matrixyl, SH-Polypeptide-91 has fewer published human studies, so its efficacy is less thoroughly documented.

Best for

  • Adults looking for a gentle anti-aging ingredient
  • Those with fine lines and early signs of aging

Use caution if

  • Anyone with a known allergy to synthetic peptides (rare)
  • Those seeking dramatic, immediate results

Usage tips

Apply after cleansing and before heavier creams to allow better absorption.
Use consistently twice daily for at least 8–12 weeks to see visible results.
Layer with a moisturizer containing ceramides or hyaluronic acid to support the skin barrier.

Safety summary

SH-Polypeptide-91 is considered safe for cosmetic use at typical concentrations. It has a low irritation and comedogenic risk, and no significant safety concerns have been reported in available literature.

Research notes

Evidence is primarily based on in vitro studies showing collagen stimulation. Human clinical data is limited but suggests potential for mild anti-aging benefits with regular use. More robust studies are needed to confirm efficacy.

Common label clues

Typical concentration
0.001% to 0.1%
Regulatory status
Approved as a cosmetic ingredient in the EU, US, and other major markets. It is not classified as a drug and cannot claim to treat or cure skin conditions.
Common uses
Anti-aging serums, Firming creams, Eye treatments
Environmental note
As a synthetic peptide, it is produced in controlled lab conditions, which reduces the environmental impact compared to harvesting from natural sources.

Good to know

  • Peptides are often listed near the end of ingredient lists because they are effective at very low concentrations.
  • SH-Polypeptide-91 is water-soluble, so it works well in gel-based or lightweight serum formulas.

Common questions

What is SH-Polypeptide-91 in beauty products?

SH-Polypeptide-91 is a tiny protein fragment made in a lab. When applied to skin, it acts like a messenger, telling skin cells to make more collagen and elastin. This can help plump up the skin and soften the look of fine lines over time. It's a gentle ingredient, unlikely to cause irritation, and is often found in anti-aging serums and creams.

What does SH-Polypeptide-91 do in a beauty product?

It binds to receptors on skin cells (fibroblasts) and triggers a cascade of signals that increase the synthesis of collagen and other structural proteins. This helps reinforce the skin's support network, leading to firmer, smoother skin with continued use.

Is SH-Polypeptide-91 safe for most people?

SH-Polypeptide-91 is considered safe for cosmetic use at typical concentrations. It has a low irritation and comedogenic risk, and no significant safety concerns have been reported in available literature.

Who should be careful with SH-Polypeptide-91?

Anyone with a known allergy to synthetic peptides (rare) Those seeking dramatic, immediate 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.