Ingredient review
RH-Polypeptide-45
INCI: RH-Polypeptide-45
A lab-made peptide that may help reduce fine lines and improve skin firmness, but human studies are limited.
In plain English
RH-Polypeptide-45 is a short chain of amino acids (the building blocks of proteins) made in a lab to mimic natural signaling molecules in your skin. When applied in a cream or serum, it sends a message to skin cells to produce more collagen and elastin, which are the proteins that keep skin plump and firm. Think of it as a gentle nudge to your skin's repair system, not a magic eraser.
Review score
Safety, usefulness, and evidence
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
Quick decision guide
Useful, but context matters
RH-Polypeptide-45 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 RH-Polypeptide-45.
- 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
moderateThere is useful support, but formula details and claim strength still matter.
What it is
RH-Polypeptide-45 is a synthetic peptide, specifically a recombinant human polypeptide, meaning it's engineered to be identical to a natural human signaling peptide. It belongs to a class of ingredients called 'matrikines' that are designed to stimulate collagen synthesis.
How it works
In a cosmetic product, RH-Polypeptide-45 penetrates the upper layers of the skin and binds to receptors on fibroblasts (the cells that make collagen). This binding triggers a cascade of signals that upregulate the production of collagen and other extracellular matrix components, potentially leading to firmer, smoother skin over weeks of consistent use.
Pros
Gentle on skin
RH-Polypeptide-45 has a low irritation and comedogenic risk, making it suitable for most skin types, including sensitive skin.
Targeted anti-aging support
It works by mimicking natural signals to boost collagen, which can help improve skin firmness and reduce fine lines over time.
Cons and cautions
Limited human evidence
Most research on this specific peptide is from lab or animal studies; robust human clinical trials are scarce, so the real-world efficacy is less certain.
Slow, subtle results
You won't see changes overnight. It typically takes 8–12 weeks of daily use to notice any visible improvement, and results are often modest.
Best for
- Adults looking for a gentle anti-aging ingredient to add to their routine
- People with mild to moderate fine lines who want a non-irritating option
Use caution if
- Those with known allergies to synthetic peptides (rare)
- Anyone expecting instant or dramatic results from a single product
Usage tips
Safety summary
RH-Polypeptide-45 is considered safe for topical cosmetic use at typical concentrations. No significant adverse effects have been reported in available safety assessments, but long-term human data is limited.
Research notes
Evidence for RH-Polypeptide-45 is primarily from in vitro (lab) studies showing collagen stimulation. Human studies are limited, but the mechanism is similar to other well-studied peptides. More clinical research is needed to confirm its anti-aging benefits.
Common label clues
- Typical concentration
- Typically used at 0.1% to 2% in leave-on formulations
- Regulatory status
- Approved for use in cosmetics in the EU, US, and other major markets. It is not classified as a drug ingredient.
- 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 biodegradable.
Good to know
- Peptides are often listed near the end of ingredient lists because they are effective at low concentrations.
- RH-Polypeptide-45 is not the same as growth factors; it's a signaling peptide, not a hormone.
Common questions
What is RH-Polypeptide-45 in beauty products?
RH-Polypeptide-45 is a short chain of amino acids (the building blocks of proteins) made in a lab to mimic natural signaling molecules in your skin. When applied in a cream or serum, it sends a message to skin cells to produce more collagen and elastin, which are the proteins that keep skin plump and firm. Think of it as a gentle nudge to your skin's repair system, not a magic eraser.
What does RH-Polypeptide-45 do in a beauty product?
In a cosmetic product, RH-Polypeptide-45 penetrates the upper layers of the skin and binds to receptors on fibroblasts (the cells that make collagen). This binding triggers a cascade of signals that upregulate the production of collagen and other extracellular matrix components, potentially leading to firmer, smoother skin over weeks of consistent use.
Is RH-Polypeptide-45 safe for most people?
RH-Polypeptide-45 is considered safe for topical cosmetic use at typical concentrations. No significant adverse effects have been reported in available safety assessments, but long-term human data is limited.
Who should be careful with RH-Polypeptide-45?
Those with known allergies to synthetic peptides (rare) Anyone expecting instant or dramatic results from a single product
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.