Ingredient review

SH-Polypeptide-55

INCI: SH-Polypeptide-55

SH-Polypeptide-55 is a lab-made peptide that may help reduce fine lines and improve skin firmness, but research is still emerging.

beautyskincareanti-aging

In plain English

SH-Polypeptide-55 is a short chain of amino acids (the building blocks of protein) made in a lab. When applied to skin, it signals cells to produce more collagen and elastin, which are the proteins that keep skin plump and firm. Think of it as a tiny messenger that tells your skin to act younger. It's commonly 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-55 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-55.
  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

SH-Polypeptide-55 is a synthetic peptide, meaning it's a man-made fragment of a protein. It belongs to a class of ingredients called signal peptides, which are designed to mimic natural peptides that trigger collagen synthesis in the skin.

How it works

When applied topically, SH-Polypeptide-55 penetrates the outer layer of skin and binds to specific receptors on fibroblasts (the cells that produce collagen). This binding sends a signal to increase the production of collagen and other structural proteins, which can help reduce the appearance of fine lines and improve skin firmness over time.

Pros

Gentle on skin

SH-Polypeptide-55 has a low irritation and comedogenic risk, making it suitable for most skin types, including sensitive skin.

Targeted anti-aging support

It specifically signals collagen production, which can help improve skin firmness and reduce fine lines over consistent use.

Cons and cautions

Slow to show results

Peptides like SH-Polypeptide-55 require regular use for several weeks to months before visible improvements appear.

Limited independent research

Most evidence comes from manufacturer studies, and independent peer-reviewed research on this specific peptide is still sparse.

Best for

  • Adults looking to reduce signs of aging
  • People with mild to moderate fine lines who want a gentle anti-aging option

Use caution if

  • Those with known allergies to synthetic peptides (rare)
  • Anyone seeking instant results—peptides take weeks to show effects

Usage tips

Apply products with SH-Polypeptide-55 to clean, damp skin to enhance absorption.
Use consistently twice daily for at least 8-12 weeks to see potential benefits.
Layer with a moisturizer containing ceramides or niacinamide to support the skin barrier.

Safety summary

SH-Polypeptide-55 is considered safe for topical use in cosmetics at typical concentrations. It has low irritation and comedogenic potential. However, as with any new ingredient, patch testing is recommended for those with very sensitive skin.

Research notes

Research on SH-Polypeptide-55 is primarily from manufacturer studies showing it can stimulate collagen production in vitro. Human clinical trials are limited, but existing evidence suggests it is a promising anti-aging ingredient with a good safety profile.

Common label clues

Typical concentration
Typically used at 0.1% to 2% in leave-on products
Regulatory status
SH-Polypeptide-55 is not specifically regulated by the FDA as a drug; it is considered a cosmetic ingredient and must be safe for its intended use. It is listed in the INCI database and used globally in cosmetics.
Common uses
Anti-aging serums, Firming creams, Eye treatments
Environmental note
As a synthetic peptide, its production involves chemical synthesis, which has a moderate environmental footprint compared to natural extracts, but it is not known to be bioaccumulative or toxic to aquatic life.

Good to know

  • SH-Polypeptide-55 is often combined with other peptides or antioxidants in anti-aging formulations.
  • It is stable in most pH ranges found in skincare, but avoid using with very low pH (under 4) products that may degrade it.

Common questions

What is SH-Polypeptide-55 in beauty products?

SH-Polypeptide-55 is a short chain of amino acids (the building blocks of protein) made in a lab. When applied to skin, it signals cells to produce more collagen and elastin, which are the proteins that keep skin plump and firm. Think of it as a tiny messenger that tells your skin to act younger. It's commonly found in anti-aging serums and creams.

What does SH-Polypeptide-55 do in a beauty product?

When applied topically, SH-Polypeptide-55 penetrates the outer layer of skin and binds to specific receptors on fibroblasts (the cells that produce collagen). This binding sends a signal to increase the production of collagen and other structural proteins, which can help reduce the appearance of fine lines and improve skin firmness over time.

Is SH-Polypeptide-55 safe for most people?

SH-Polypeptide-55 is considered safe for topical use in cosmetics at typical concentrations. It has low irritation and comedogenic potential. However, as with any new ingredient, patch testing is recommended for those with very sensitive skin.

Who should be careful with SH-Polypeptide-55?

Those with known allergies to synthetic peptides (rare) Anyone seeking instant results—peptides take weeks to show effects

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.