Ingredient review
Endonuclease V
INCI: Endonuclease V
A biotech enzyme that helps skin repair UV-damaged DNA, but its effectiveness in everyday skincare is still being studied.
In plain English
Endonuclease V is a lab-made enzyme originally from a virus that infects bacteria. In skincare, it's added to help your skin cells fix damage caused by UV rays from the sun. Think of it as a tiny repair crew that finds and snips out broken parts of your skin's DNA so your cells can patch them up. It's not a sunscreen or a cure for sunburn, but it may support your skin's natural repair process after sun exposure.
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
- biotech
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Endonuclease V 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 Endonuclease V.
- 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
Endonuclease V is a genetically engineered enzyme (T4 endonuclease V) that targets cyclobutane pyrimidine dimers, the most common type of DNA damage caused by UVB radiation. It is typically delivered in a liposomal formulation to help it penetrate the skin.
How it works
When applied to skin, the enzyme enters skin cells and scans the DNA for UV-induced damage. It cuts the damaged strand at the site of the dimer, initiating a natural repair process called nucleotide excision repair. This helps the cell remove and replace the damaged DNA segment.
Pros
Targeted DNA repair
Specifically addresses UV-induced DNA dimers, a key cause of skin aging and cancer risk.
Backed by clinical studies
Some research shows it reduces actinic keratosis and may lower skin cancer risk in high-risk individuals.
Cons and cautions
Limited consumer products
Endonuclease V is not widely available in over-the-counter skincare; most products are medical or professional-grade.
Delivery challenges
The enzyme must be properly formulated (often in liposomes) to penetrate skin, and not all products achieve this effectively.
Best for
- People concerned about sun damage and photoaging
- Those looking for advanced post-sun skincare support
Use caution if
- People with very sensitive or compromised skin barriers (due to lack of safety data)
- Those expecting immediate or dramatic results
Usage tips
Safety summary
Endonuclease V is considered safe for topical use in cosmetics at typical concentrations. It is non-irritating and non-sensitizing in most people. However, long-term safety data in healthy consumers is limited, and it should not be used on broken or severely damaged skin.
Research notes
Clinical studies, including a randomized controlled trial, show that topical T4 endonuclease V reduces the rate of new actinic keratoses and may lower the risk of basal cell carcinoma in patients with xeroderma pigmentosum. Evidence in healthy individuals is less robust but promising for supporting skin repair.
Common label clues
- Typical concentration
- 0.01% to 0.1% in leave-on formulations
- Regulatory status
- Generally recognized as safe for topical use in cosmetics in the US and EU, but not approved as a drug for treating or preventing skin cancer.
- Common uses
- Post-sun repair serums, Anti-aging treatments, Photodamage recovery products
- Environmental note
- Produced via biotechnology (fermentation of genetically modified E. coli), so it has a lower environmental footprint than animal-derived enzymes.
Good to know
- Endonuclease V is often paired with other DNA repair enzymes in 'photolyase' or 'repair enzyme' blends.
- It was originally studied for medical use in preventing skin cancer in organ transplant patients.
Common questions
What is Endonuclease V in beauty products?
Endonuclease V is a lab-made enzyme originally from a virus that infects bacteria. In skincare, it's added to help your skin cells fix damage caused by UV rays from the sun. Think of it as a tiny repair crew that finds and snips out broken parts of your skin's DNA so your cells can patch them up. It's not a sunscreen or a cure for sunburn, but it may support your skin's natural repair process after sun exposure.
What does Endonuclease V do in a beauty product?
When applied to skin, the enzyme enters skin cells and scans the DNA for UV-induced damage. It cuts the damaged strand at the site of the dimer, initiating a natural repair process called nucleotide excision repair. This helps the cell remove and replace the damaged DNA segment.
Is Endonuclease V safe for most people?
Endonuclease V is considered safe for topical use in cosmetics at typical concentrations. It is non-irritating and non-sensitizing in most people. However, long-term safety data in healthy consumers is limited, and it should not be used on broken or severely damaged skin.
Who should be careful with Endonuclease V?
People with very sensitive or compromised skin barriers (due to lack of safety data) Those expecting immediate or dramatic results
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.