Ingredient review

Kojyl Carboxy Dipeptide-23

INCI: Kojyl Carboxy Dipeptide-23

A synthetic peptide that may help brighten skin and fade dark spots, but research is still limited.

beautyskincarebrightening agent

In plain English

Kojyl Carboxy Dipeptide-23 is a lab-made ingredient that combines a kojic acid derivative with a peptide. It is designed to help reduce the appearance of dark spots and uneven skin tone by interfering with the production of melanin, the pigment that gives skin its color. Think of it as a gentler alternative to some stronger brighteners, but with less scientific backing so far.

Review score

Safety, usefulness, and evidence

3.8Good
3.8/ 5

Potentially useful with some tradeoffs

The evidence base is still emerging, so marketing claims deserve extra caution.

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

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

Quick decision guide

Useful, but context matters

Kojyl Carboxy Dipeptide-23 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 Kojyl Carboxy Dipeptide-23.
  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

emerging

The ingredient may be promising, but claims should be treated more cautiously.

What it is

A synthetic peptide conjugate, meaning a small protein fragment (dipeptide) is chemically linked to a kojic acid derivative. Kojic acid is a well-known skin brightener from fungi, and the peptide part is meant to improve stability and delivery into the skin.

How it works

It is believed to inhibit tyrosinase, an enzyme involved in melanin production. By slowing down this enzyme, the ingredient can help prevent excess pigment from forming, leading to a more even skin tone over time. The peptide component may also support delivery deeper into the skin.

Pros

Gentle brightening

Unlike some harsh brighteners, this peptide is considered low-irritation and suitable for sensitive skin types.

Stable formula

The peptide conjugation may make the ingredient more stable in formulations compared to plain kojic acid, which can degrade in light and air.

Cons and cautions

Limited evidence

Most of the supporting data comes from lab or animal studies, not large human trials, so its real-world effectiveness is not fully proven.

Slow results

Brightening ingredients generally take consistent use over several weeks to show visible improvement, and this one is no exception.

Best for

  • People with mild to moderate dark spots or uneven skin tone
  • Those looking for a gentle brightening ingredient

Use caution if

  • Anyone allergic to kojic acid or peptides

Usage tips

Use consistently twice daily for best results.
Always follow with a broad-spectrum sunscreen during the day, as brightening ingredients can make skin more sensitive to UV.

Safety summary

Kojyl Carboxy Dipeptide-23 is considered safe for topical use with low irritation and comedogenic risk. However, long-term safety data is limited due to its relatively recent introduction.

Research notes

Research is preliminary. In vitro studies show tyrosinase inhibition, but there are few published human trials. More evidence is needed to confirm its efficacy compared to established brighteners.

Common label clues

Typical concentration
0.1% to 1%
Regulatory status
Generally recognized as safe for cosmetic use in the US and EU when used within recommended concentrations.
Common uses
Serums, Moisturizers, Spot treatments
Environmental note
As a synthetic ingredient, it does not rely on natural harvesting, which can be a plus for sustainability.

Good to know

  • This ingredient is often found in serums and spot treatments targeting hyperpigmentation.
  • It is not the same as pure kojic acid, so check the full ingredient list if you have a known sensitivity.

Common questions

What is Kojyl Carboxy Dipeptide-23 in beauty products?

Kojyl Carboxy Dipeptide-23 is a lab-made ingredient that combines a kojic acid derivative with a peptide. It is designed to help reduce the appearance of dark spots and uneven skin tone by interfering with the production of melanin, the pigment that gives skin its color. Think of it as a gentler alternative to some stronger brighteners, but with less scientific backing so far.

What does Kojyl Carboxy Dipeptide-23 do in a beauty product?

It is believed to inhibit tyrosinase, an enzyme involved in melanin production. By slowing down this enzyme, the ingredient can help prevent excess pigment from forming, leading to a more even skin tone over time. The peptide component may also support delivery deeper into the skin.

Is Kojyl Carboxy Dipeptide-23 safe for most people?

Kojyl Carboxy Dipeptide-23 is considered safe for topical use with low irritation and comedogenic risk. However, long-term safety data is limited due to its relatively recent introduction.

Who should be careful with Kojyl Carboxy Dipeptide-23?

Anyone allergic to kojic acid or peptides

Research sources

CosIng (EU Cosmetic Ingredient Database)OpenPubMed - Peptides in Skin BrighteningOpen

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.