Ingredient review

Nonapeptide-37

INCI: Nonapeptide-37

A synthetic peptide that may help soften expression lines by temporarily relaxing facial muscles, similar to but milder than neurotoxins.

beautyskincareanti-aging

In plain English

Nonapeptide-37 is a lab-made protein fragment (a peptide) designed to mimic the action of certain natural proteins that relax facial muscles. When applied in a cream or serum, it can temporarily reduce the intensity of muscle contractions that cause expression lines, like crow's feet or forehead wrinkles. Think of it as a very gentle, topical alternative to injectable treatments—it won't freeze your face, but it may help lines look less noticeable over time.

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

Nonapeptide-37 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 Nonapeptide-37.
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

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

Nonapeptide-37 is a synthetic peptide composed of nine amino acids. It belongs to a class of peptides known as 'neurotransmitter-inhibiting peptides' because they interfere with the release of acetylcholine, a chemical that signals muscles to contract.

How it works

When applied to the skin, Nonapeptide-37 is absorbed into the upper layers where it can reach the nerve endings around facial muscles. It works by blocking the release of acetylcholine, which reduces the intensity of muscle contractions. This leads to a temporary smoothing of expression lines without paralyzing the muscles.

Pros

Gentle muscle relaxation

Nonapeptide-37 works by temporarily reducing muscle contractions, which can soften expression lines without the numbness or downtime of injectables.

Low irritation risk

As a synthetic peptide, it is generally well-tolerated by most skin types, including sensitive skin, with minimal reports of irritation.

Cons and cautions

Subtle, gradual results

Unlike injectable treatments, the effects are mild and build up over weeks of consistent use. You won't see an overnight change.

Requires ongoing use

The anti-wrinkle effect is temporary and fades once you stop using the product, so it needs to be part of your daily routine to maintain results.

Best for

People looking for a gentle, non-invasive way to soften expression lines
Those who want to complement their anti-aging routine with a peptide serum

Use caution if

Anyone with known allergies to synthetic peptides (rare)
Those expecting dramatic, immediate results similar to injectables

Usage tips

Apply to clean, dry skin before heavier creams to maximize absorption.

Use consistently twice daily for at least 8-12 weeks to see noticeable improvement.

Pair with a broad-spectrum sunscreen to protect the skin and prevent new wrinkles from forming.

Safety summary

Nonapeptide-37 is considered safe for topical cosmetic use at typical concentrations. It has a low irritation and comedogenic risk, making it suitable for most skin types. There are no known serious side effects, but as with any ingredient, patch testing is recommended for those with very sensitive skin.

Research notes

Clinical studies on neurotransmitter-inhibiting peptides like Nonapeptide-37 show modest improvements in wrinkle depth and skin smoothness after 4-8 weeks of use. Most evidence comes from small-scale studies and ingredient manufacturer data. While promising, more independent peer-reviewed research is needed to confirm long-term efficacy.

Common label clues

Typical concentration: Typically used at 0.5% to 2% in leave-on products
Regulatory status: Approved as a cosmetic ingredient in the EU, US, and most major markets. It is not classified as a drug and cannot claim to treat or cure medical conditions.
Common uses: Anti-aging serums, Eye creams, Facial moisturizers
Environmental note: As a synthetic peptide, it is produced in a lab, which reduces the need for animal-derived ingredients. However, its environmental impact depends on the manufacturing process.

Good to know

Nonapeptide-37 is often used alongside other peptides like Matrixyl for a more comprehensive anti-aging effect.
It is stable in most formulations but may be less effective in very low pH products.

Common questions

What is Nonapeptide-37 in beauty products?

What does Nonapeptide-37 do in a beauty product?

Is Nonapeptide-37 safe for most people?

Who should be careful with Nonapeptide-37?

Anyone with known allergies to synthetic peptides (rare) Those expecting dramatic, immediate results similar to injectables

Research sources

Cosmetic Ingredient Review (CIR) - Safety of PeptidesOpen PubMed - Peptides in CosmeticsOpen INCI Database - Nonapeptide-37Open

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.