SH-Polypeptide-3 is a recombinant human keratinocyte growth factor used in skincare. Learn what it does, the evidence behind it, and safety basics.
SH-Polypeptide-3 is a bioengineered, recombinant form of human keratinocyte growth factor (KGF), also known as FGF-7. It shows up in topical serums and creams sold for barrier repair, skin renewal, and post-procedure recovery. It is a cosmetic ingredient rather than an approved drug, and most of its supporting science comes from laboratory and animal research rather than large clinical trials in people.
What SH-Polypeptide-3 Actually Is
The "sh" prefix stands for "synthetic human," the INCI convention for a human peptide sequence produced in a laboratory host cell. Manufacturers insert the human gene into bacteria or yeast, let those cells manufacture the peptide, and then purify it. The finished molecule is designed to match the naturally occurring human signaling protein.
In other words, SH-Polypeptide-3 shares the same polypeptide structure as the KGF your own keratinocytes respond to, with the same amino acid chain and folding. The distinction between polypeptide vs protein is mostly about length and complexity: peptides are short amino acid chains, while proteins are longer chains folded into a stable three-dimensional shape.
KGF is a 163-amino-acid signaling molecule, so by strict size definitions it sits closer to the protein end of that spectrum. Cosmetic regulators still file it inside the "polypeptide" naming family, which is why the label reads the way it does.
How It Works in the Skin
Keratinocytes are the cells that build the outer layer of your skin. In the body, KGF is released by fibroblasts in the dermis and binds to FGFR2b receptors on keratinocytes, signaling them to divide, migrate, and rebuild the barrier. This pathway is a normal part of wound re-epithelialization.
Applied topically, the story gets more complicated. KGF is a relatively large, water-soluble molecule, and large molecules cross intact skin poorly. Formulators work around that limit with liposomes, penetration enhancers, and delivery systems, but how much peptide actually reaches living keratinocytes from a real serum is an open question.
SH-Polypeptide-3 vs Other Growth Factor Peptides
Growth factor peptides are named by number, not by function, so the INCI list gives you almost no clue about what each one does. The table below maps the most common entries.
| INCI name | Commonly described as | Primary cell target |
|---|---|---|
| sh-Oligopeptide-1 | Epidermal growth factor (EGF) | Keratinocytes and fibroblasts; epidermal turnover |
| sh-Polypeptide-1 | Basic fibroblast growth factor (FGF-2) | Fibroblasts in the dermis; matrix support |
| sh-Polypeptide-3 | Keratinocyte growth factor (KGF / FGF-7) | Keratinocytes in the epidermis; barrier signaling |
| Copper tripeptide-1 (GHK-Cu) | A copper-binding carrier peptide, not a growth factor | Collagen and repair signaling |
Supplier technical dossiers, not the INCI name, are the only reliable source of function. The entry sh polypeptide 2 belongs to the same recombinant family but carries its own documentation, and sh-polypeptide 123 is a newer listing sold mainly in firming and barrier-support products. Do not assume that similarly numbered ingredients behave alike.
What the Research Shows, and What It Does Not
There is a solid reason KGF appears in so many formulas: its biology is real and well studied. Recombinant human KGF was developed as an injectable drug called palifermin and received FDA approval in 2004 to prevent severe oral mucositis in chemotherapy patients. That product was later discontinued by its manufacturer for commercial reasons, not because of a safety finding.
That history does not transfer to a face cream. Approval of an injectable drug says nothing about whether a topical serum delivers a useful dose to the epidermis, and no large independent trial has shown that a topical KGF product reverses wrinkles or repairs sun damage in humans. Most published work is in vitro or animal-based.
SH-Polypeptide-3 is not FDA-approved for human use as a topical drug, and cosmetic products containing it are not reviewed by the FDA for effectiveness before they are sold.
Safety, Side Effects, and Cautions
Topically applied peptides in this family have a good safety record in cosmetics. Reported problems are usually mild and local, such as redness, stinging, itching, or irritation, and they often come from other ingredients in the formula rather than the peptide itself.
Skip growth factor products on broken skin, active eczema or psoriasis flares, open wounds, and any area with a skin infection. Anyone with a history of skin cancer or a precancerous lesion should talk with a dermatologist before using signaling peptides on a regular basis.
Searches for sh-polypeptide-121 pregnancy safe reflect the same data gap: there are no controlled human studies of topical growth factor peptides during pregnancy. If you are pregnant or breastfeeding, ask your obstetrician or dermatologist before starting one.
Never inject a cosmetic peptide serum. Unregulated injectable "growth factor" products are not sterile drugs and carry real risks of infection and granuloma formation.
How to Read a Label and Use It Well
- Check the position. Ingredients are listed in descending order of concentration, so a peptide near the end of a long list is likely present in trace amounts.
- Look at the packaging. Peptides are fragile. Airless pumps, opaque bottles, and single-dose ampoules protect them better than a wide-mouth jar.
- Patch test first. Apply to the inner forearm for 24 to 48 hours before using it on your face.
- Start slowly. Once daily at night is enough for most people, and more frequent use has not been shown to work better.
- Layer sensibly. Apply after cleansing and before moisturizer, and separate it from strong acids or retinoids by about 20 to 30 minutes.
- Keep sunscreen in the routine. No peptide outperforms daily UV protection when it comes to visible skin aging.
Bottom Line
- SH-Polypeptide-3 is a recombinant human keratinocyte growth factor (KGF / FGF-7) used as a cosmetic ingredient in topical skincare.
- Its wound-healing biology is well documented, but evidence that topical serums visibly rejuvenate skin is thin and largely indirect.
- SH-Polypeptide-3 is not FDA-approved as a drug, and no topical cosmetic containing it has been proven to reverse wrinkles.
- Topical use is generally well tolerated, but pregnant and breastfeeding users should clear it with a clinician first.
- Real-world results depend heavily on formulation and delivery, so the INCI name alone says very little about a product's quality.
Frequently Asked Questions
Is sh-polypeptide-3 the same thing as a growth factor?
Yes. SH-Polypeptide-3 is the INCI name for a recombinant human keratinocyte growth factor, also called KGF or FGF-7. It is produced by inserting the human gene into a host cell, and the resulting peptide mimics the signaling molecule your skin makes naturally.
Is sh-polypeptide-3 safe to put on your face?
Topical peptides in this family are generally well tolerated, and irritation is usually mild and temporary. Patch test first, avoid broken or infected skin, and check with a dermatologist if you are pregnant, breastfeeding, or being treated for a skin condition.
Does sh-polypeptide-3 actually reduce wrinkles?
There is no large, independent human trial showing that a topical KGF product visibly reverses wrinkles. The ingredient has well-documented wound-healing biology, but results depend on how well a formula delivers a large peptide into living skin, which is difficult.
This page provides educational research information and does not replace medical advice, diagnosis, or treatment.