# 111SKIN Y Theorem Repair Light Serum NAC Y2 for mature skin

**Lovi Fit: Average fit for mature skin.**
Normal Skin Fit: High · Effectiveness: Average · Safety: Excellent.

Page: https://lovi.care/skincare/ie/p/111skin/y-theorem-repair-light-serum-nac-y2/for/mature-skin

The Lovi Fit is the same in every country; only the stores and prices differ, and the ones here are for Ireland.

Brand: [111SKIN](https://lovi.care/skincare/ie/brands/111skin)
Category: [Serums and treatments](https://lovi.care/skincare/ie/best/serums)

This fit is calculated for the concerns frequently associated with mature skin: fine lines, wrinkles, and loss of firmness. For scores based on a full skin profile (12D face scan, goals, preferences), use the Lovi app.

Works for mature skin; other serums fit it better.

## Why this fit

- Offers moderate benefits for your normal skin, as acetyl cysteine and niacinamide enhance barrier resilience and even skin tone, while glycerin and aloe barbadensis extract provide hydration.
- While it offers general skincare benefits, it lacks specialized ingredients to effectively target your wrinkles and fine lines.
- The product is safe for your normal skin due to the absence of harsh ingredients and the presence of soothing agents like Aloe Barbadensis Extract and Calendula Officinalis Extract.

## Fit by skin type

- [Oily skin](https://lovi.care/skincare/ie/p/111skin/y-theorem-repair-light-serum-nac-y2/for/oily-skin): Average
- [Dry skin](https://lovi.care/skincare/ie/p/111skin/y-theorem-repair-light-serum-nac-y2/for/dry-skin): Average
- [Combination skin](https://lovi.care/skincare/ie/p/111skin/y-theorem-repair-light-serum-nac-y2/for/combination-skin): Average
- [Sensitive skin](https://lovi.care/skincare/ie/p/111skin/y-theorem-repair-light-serum-nac-y2/for/sensitive-skin): Average
- [Acne-prone skin](https://lovi.care/skincare/ie/p/111skin/y-theorem-repair-light-serum-nac-y2/for/acne-prone-skin): Average
- [Skin with dark spots](https://lovi.care/skincare/ie/p/111skin/y-theorem-repair-light-serum-nac-y2/for/dark-spots): Average
- [Mature skin](https://lovi.care/skincare/ie/p/111skin/y-theorem-repair-light-serum-nac-y2/for/mature-skin): Average (this page)
- [Dry sensitive skin](https://lovi.care/skincare/ie/p/111skin/y-theorem-repair-light-serum-nac-y2/for/dry-sensitive-skin): Average
- [Oily acne-prone skin](https://lovi.care/skincare/ie/p/111skin/y-theorem-repair-light-serum-nac-y2/for/oily-acne-prone-skin): Average

## Key ingredients

Nac Y2, Niacinamide, Calendula Officinalis Extract, Aloe Barbadensis Extract, Acetyl Cysteine

## What the research says

- Niacinamide significantly decreased hyperpigmentation and increased skin lightness compared with vehicle alone after 4 weeks of use in women by inhibiting melanosome transfer. ([The British Journal of Dermatology, 2002](https://pubmed.ncbi.nlm.nih.gov/12100180/))
- Topical post-laser application of human adipocyte-derived mesenchymal stem cell media combined with niacinamide significantly improved wrinkle index, melanin index, patient satisfaction, and investigator esthetic improvement scores compared to vehicle cream in patients with aging skin. ([Journal of Cosmetic Dermatology, 2021](https://pubmed.ncbi.nlm.nih.gov/33103316/))
- Glutathione amino acid precursors effectively increase cellular glutathione levels, reducing oxidative stress, ATP depletion, and DNA damage in human keratinocytes, clinical subjects, and ex vivo skin compared to controls. ([Journal of the European Academy of Dermatology and Venereology, 2024](https://pubmed.ncbi.nlm.nih.gov/38189670/))
- Topical glutathione improves hyperpigmentation, reduces ultraviolet-induced erythema and wrinkles, decreases transepidermal water loss, and enhances antioxidant capacity. ([The Journal of Clinical and Aesthetic Dermatology, 2025](https://pubmed.ncbi.nlm.nih.gov/41416233/))
- RayGel reduced skin reaction severity with a lower average score of 93.7 compared to 123.3 for the placebo group in patients undergoing whole breast external-beam irradiation. ([American Journal of Surgery, 2005](https://pubmed.ncbi.nlm.nih.gov/15862509/))
- Topical nicotinamide prevented solar-simulated UV-induced immunosuppression in healthy volunteers, and men experienced immunosuppression at solar-simulated UV doses three times lower than those required for women. ([The Journal of Investigative Dermatology, 2008](https://pubmed.ncbi.nlm.nih.gov/17882270/))
- Topical 5% niacinamide applied twice daily for 12 weeks reduced fine lines and wrinkles, hyperpigmented spots, red blotchiness, and skin sallowness, and improved skin elasticity compared to vehicle control in 50 female white subjects with facial photoaging. ([Dermatologic Surgery, 2005](https://pubmed.ncbi.nlm.nih.gov/16029679/))
- Topical 2% niacinamide significantly decreased sebum excretion rate in Japanese individuals and casual sebum levels in Caucasian individuals compared to placebo or baseline. ([Journal of Cosmetic and Laser Therapy, 2006](https://pubmed.ncbi.nlm.nih.gov/16766489/))
- Topical application of Calendula officinalis extract cream significantly improved skin hydration and firmness (reflected in significant changes in R0 and R6 parameters) in 21 healthy human volunteers compared to a base cream. ([Acta Poloniae Pharmaceutica, 2011](https://pubmed.ncbi.nlm.nih.gov/21928714/))
- Treatment with standardized extract of Calendula officinalis L. led to a shorter epithelization time and faster healing speed compared to mineral oil in patients with acute skin loss wounds of the hand and fingers healing by secondary intention. ([Tissue Barriers, 2022](https://pubmed.ncbi.nlm.nih.gov/34674610/))
- Topical administration of Calendula provides weak evidence of effectiveness in acute and chronic wounds compared to standard treatments based on a narrative review of available trials. ([Wounds, 2008](https://pubmed.ncbi.nlm.nih.gov/25941793/))
- A cream combining propolis, tea tree oil, and Aloe vera reduced erythema scars, acne severity index, and total lesion count better than erythromycin cream in sixty patients with mild to moderate acne vulgaris compared to placebo. ([Clinical Pharmacology, 2018](https://pubmed.ncbi.nlm.nih.gov/30588129/))
- Topical aloe vera gel significantly accelerated split-thickness skin graft donor-site healing compared to placebo in 12 patients, but showed no significant difference in pain relief. ([Plastic and Reconstructive Surgery, 2018](https://pubmed.ncbi.nlm.nih.gov/29649056/))
- Topical application of Aloe vera cream reduced postoperative pain at rest and during defecation, accelerated wound healing at two weeks, and decreased analgesic requirements in patients after open hemorrhoidectomy compared to placebo. ([Journal of Alternative and Complementary Medicine, 2010](https://pubmed.ncbi.nlm.nih.gov/20569031/))
- Topical N-acetylcysteine plus doxycycline achieved significantly greater improvements in total lesion count, inflammatory lesion count, IGA, GAGS, and CADI scores compared to benzoyl peroxide plus doxycycline in 40 patients with moderate acne vulgaris. ([Dermatology Practical & Conceptual, 2026](https://pubmed.ncbi.nlm.nih.gov/42190184/))
- Topical application of alpha-tocopherol, l-ascorbic acid, alpha-lipoic acid, glutathione ethylester, and N-acetylcysteine decreased UVB-radiation-induced cell death, apoptosis, and lipid peroxidation in ex vivo pig skin explants compared to untreated controls. ([Radiation Research, 2003](https://pubmed.ncbi.nlm.nih.gov/12537526/))
- Topical vitamin C, vitamin E, and acetylcysteine showed similar effects on the healing of experimentally created corneal wounds in rabbits, with no statistically significant differences compared to each other. ([Indian Journal of Ophthalmology, 2020](https://pubmed.ncbi.nlm.nih.gov/33229673/))

## Why other serums fit mature skin better

- Caviar oil enhanced adipocyte differentiation in vitro, reduced MMP expression while increasing collagen and elastin formation ex vivo, and improved skin moisture, elasticity, and density in 102 participants over four weeks of Cavi Balm usage compared to baseline. ([In Vivo, 2023](https://pubmed.ncbi.nlm.nih.gov/37652485/))
- Chronomodulated daytime application of baicalin and nighttime application of palmitoyl tripeptide-1 synergistically improved skin luminance by 16.29%, nasolabial fold depth by -36.35%, and firmness by 24.35% in 30 female participants. ([Journal of Cosmetic Dermatology, 2026](https://pubmed.ncbi.nlm.nih.gov/41527525/))
- A topical serum containing vitamin C, vitamin E, and raspberry leaf cell culture extract improved skin color, elasticity, radiance, smoothness, scaliness, and wrinkles compared to the untreated contralateral side in fifty female volunteers. ([Journal of Cosmetic Dermatology, 2020](https://pubmed.ncbi.nlm.nih.gov/31975502/))

## What reviewers say

Users with oily, combination, or humid-climate skin praise the serum's lightweight, water-like texture for providing deep hydration without greasiness, often noting significant improvements in redness, inflammation, and post-procedure healing. A notable portion of reviewers feel the extremely high price point is unjustified, citing strong fragrance and a lack of dramatic anti-aging results as key drawbacks compared to more affordable alternatives.

- Liked: Lightweight & fast-absorbing (mostly mentioned)
- Disliked: Extremely expensive (mostly mentioned)
- Liked: Hydrating & plumping (often mentioned)
- Liked: Soothing & healing (often mentioned)
- Liked: Good for oily skin (sometimes noted)
- Disliked: Lack of visible results (sometimes noted)
- Disliked: Strong fragrance (sometimes noted)
- Disliked: Potential irritation (rarely noted)

## How to apply

- Use this serum in your PM routine. Start by applying it 3 times a week, and work up to daily use if your skin likes it.
- Apply this serum after your toner and before your moisturizer.
- Gently press 2-3 drops of the serum into your skin and let it absorb for a minute.
- You can apply the serum on dry skin for the best results against fine lines.
- Always do a patch test before your first use and avoid the sensitive eye area.
- Video: https://storage.pora.ai/c879dda8655a61c19d3d8c9ebad6b06d.mp4

## Questions and answers

### How well does 111SKIN Y Theorem Repair Light Serum work for mature skin?

This serum works moderately well for mature skin, helping to even skin tone and provide hydration, but it lacks specialized ingredients to effectively target wrinkles and fine lines. A product of this type needs high-quality anti-aging ingredients, potent antioxidants, peptides, and deep moisturizers to smooth lines and improve skin elasticity.
Sources: [The British Journal of Dermatology, 2002](https://pubmed.ncbi.nlm.nih.gov/12100180/)

### Which ingredients make this serum a good fit for mature skin?

Acetyl cysteine and niacinamide help make this serum a good fit for mature skin by supporting skin barrier resilience and evening out skin tone, while glycerin and aloe provide hydration. Because it lacks specialized ingredients to effectively target wrinkles and fine lines, a treatment for mature skin needs potent antioxidants, peptides, and high-quality ingredients that specifically improve skin firmness and hydration.
Sources: [The British Journal of Dermatology, 2002](https://pubmed.ncbi.nlm.nih.gov/12100180/)

### What does Nac Y2 do for mature skin?

NAC Y2 helps support mature skin by acting as an antioxidant that protects against environmental damage and helps smooth the look of lines. It is unlikely to cause irritation and works well to keep skin looking calm and healthy.
Sources: [The Journal of Investigative Dermatology, 2003](https://pubmed.ncbi.nlm.nih.gov/12713590/), [Indian Journal of Dermatology, Venereology and Leprology, 2018](https://pubmed.ncbi.nlm.nih.gov/30246706/)

### What does Niacinamide do for mature skin?

Niacinamide helps mature skin by smoothing out fine lines and wrinkles, reducing dark spots, and improving overall skin elasticity. It is also very well tolerated and supports a strong skin barrier to keep skin looking healthy.
Sources: [Antioxidants, 2021](https://pubmed.ncbi.nlm.nih.gov/34439563/), [Journal of Cosmetic Dermatology, 2004](https://pubmed.ncbi.nlm.nih.gov/17147561/)

### Where does this serum go in a skincare routine for mature skin?

This serum goes in the evening routine after cleansing and before your moisturizer. Treatments with actives are placed in the evening for simplicity and extra safety around sun exposure.

### Can I use this serum with retinol, and in what order?

You can use this treatment alongside retinol by applying the serum first and following it with your retinol product, or by alternating the nights you use each one. Because this product is safe for your skin and helps soothe irritation, layering them is unlikely to cause discomfort.

### How often should I use this serum?

You can use this serum in your evening routine. A product of this type for mature skin needs powerful anti-aging ingredients like retinoids or peptides to effectively smooth fine lines and wrinkles.

### Can this serum clog pores, cause breakouts or purging for mature skin?

This serum is unlikely to clog pores or cause breakouts for mature skin because it avoids heavy oils and includes soothing ingredients like aloe and calendula. A product of this type needs specialized anti-aging ingredients like peptides or retinoids along with rich hydrators to truly smooth and firm mature skin.

### Is this serum fragrance-free and alcohol-free?

It contains fragrance (benzyl alcohol and parfum) and drying alcohol (alcohol).

## Alternatives for mature skin

- [SkinCeuticals C E Ferulic](https://lovi.care/skincare/ie/p/skinceuticals/c-e-ferulic/for/mature-skin) — Superior fit — €185.00 at Amazon
- [NEOGEN DERMALOGY REAL VITA C SERUM](https://lovi.care/skincare/ie/p/neogen-dermalogy/real-vita-c-serum/for/mature-skin) — High fit — €31.40 at Amazon
- [Augustinus Bader The Serum](https://lovi.care/skincare/ie/p/augustinus-bader/the-serum/for/mature-skin) — High fit — €385.99 at Amazon

## Pairs well with

- Cleanser: [Fresh Soy Face Cleanser](https://lovi.care/skincare/ie/p/fresh/soy-face-cleanser/for/mature-skin) — Superior fit — €56.86 at Amazon
- Hydrating Toner: [COSRX Propolis Synergy Toner](https://lovi.care/skincare/ie/p/cosrx/full-fit-propolis-synergy-toner/for/mature-skin) — Superior fit — €14.28 at Amazon
- Moisturizer: [Elizabeth Arden Ceramide Lift and Firm Night Cream](https://lovi.care/skincare/ie/p/elizabeth-arden/advanced-ceramide-lift-and-firm-night-cream/for/mature-skin) — Superior fit — €50.82 at Amazon

## Where to buy

No store in Ireland has a checked price for this product, so the page shows none.

## Ingredients

Water, Glycerin, Alcohol, Benzyl Alcohol, Aloe Barbadensis Extract, Calendula Officinalis Extract, Carbomer, Sodium Hydroxide, Aesculus Hippocastanum Extract, Sodium Ascorbyl Phosphate, Panthenol, Niacinamide, Thiamin, Riboflavin, Pyridoxine, Cyanocobalamin, Glycyrrhiza Glabra Root Extract Licorice Root Extract, Prunus Armeniaca Kernel Oil Apricot Kernel Oil, Acetyl Cysteine, Parfum
## About the Lovi Fit

Lovi: Unbiased, science-based skincare AI trained on real user outcomes.

Lovi calculates every fit score from the full ingredient list with brand-independent rules its dermatologists and cosmetic chemists build and review, and personalizes every pick with AI trained on the real results of millions of users. Lovi trains its fit score models on a proprietary dataset built from more than 10,000 expert-labeled products and more than 100,000 simulated examples, following an internally consistent methodology presented at Cosmoprof, AMWC, and Skin of Color Update. Levels from best to worst: Superior, High, Average, Low, Caution, Warning.

Behind this fit score: Nadia Kapleva, MS (Co-founder, Medical Director); Alexey Shagraev, PhD (Co-founder, CEO and CTO); Dr. Sofía Perea Pérez, MD, MSc (Medical Board); Aishani Shah, MD (Medical Board); Asya Zubkova, MS (Medical Board); Hanna Kurets, MD (Medical Board, Medical Advisor); Elina Nazarenko, MD (Medical Board); Victoria Derkova, MS (Medical Board).

Page built Nov 8, 2026.

More from Lovi: https://lovi.care/skincare/llms.txt

## This page in other countries

- United States: https://lovi.care/skincare/p/111skin/y-theorem-repair-light-serum-nac-y2/for/mature-skin
- United Kingdom: https://lovi.care/skincare/uk/p/111skin/y-theorem-repair-light-serum-nac-y2/for/mature-skin
- Ireland: https://lovi.care/skincare/ie/p/111skin/y-theorem-repair-light-serum-nac-y2/for/mature-skin (this page)
- Germany: https://lovi.care/skincare/de/p/111skin/y-theorem-repair-light-serum-nac-y2/for/mature-skin
- France: https://lovi.care/skincare/fr/p/111skin/y-theorem-repair-light-serum-nac-y2/for/mature-skin
- Italy: https://lovi.care/skincare/it/p/111skin/y-theorem-repair-light-serum-nac-y2/for/mature-skin
- Netherlands: https://lovi.care/skincare/nl/p/111skin/y-theorem-repair-light-serum-nac-y2/for/mature-skin
- Spain: https://lovi.care/skincare/es/p/111skin/y-theorem-repair-light-serum-nac-y2/for/mature-skin
- Canada: https://lovi.care/skincare/ca/p/111skin/y-theorem-repair-light-serum-nac-y2/for/mature-skin
- Australia: https://lovi.care/skincare/au/p/111skin/y-theorem-repair-light-serum-nac-y2/for/mature-skin
- Singapore: https://lovi.care/skincare/sg/p/111skin/y-theorem-repair-light-serum-nac-y2/for/mature-skin
- Saudi Arabia: https://lovi.care/skincare/sa/p/111skin/y-theorem-repair-light-serum-nac-y2/for/mature-skin
- United Arab Emirates: https://lovi.care/skincare/ae/p/111skin/y-theorem-repair-light-serum-nac-y2/for/mature-skin