# 111SKIN Y Theorem Repair Light Serum NAC Y2 for acne-prone skin

**Lovi Fit: Average fit for acne-prone skin.**
Combination Skin Fit: High · Effectiveness: Average · Safety: High.

Page: https://lovi.care/skincare/ie/p/111skin/y-theorem-repair-light-serum-nac-y2/for/acne-prone-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 acne-prone skin: breakouts, blackheads, and post-acne marks. For scores based on a full skin profile (12D face scan, goals, preferences), use the Lovi app.

Works for acne-prone skin; other serums fit it better.

## Why this fit

- Offers moderate suitability for your combination skin as niacinamide and aloe barbadensis extract provide seboregulation and humectant action, though these ingredients are not specifically targeted for acne, blemishes, and breakouts.
- The serum provides excellent skin repair with niacinamide and acetyl cysteine, enhancing barrier resilience and reducing visible signs of aging, which are general skincare benefits.
- The product is safe for your acne-prone skin, with no risks of irritation 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 (this page)
- [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
- [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

- Topical genistein and N-acetyl cysteine prevent ultraviolet-induced photoaging signaling pathways in human skin in vivo by inhibiting specific kinase activities and antioxidant mechanisms without acting as sunscreens. ([The Journal of Investigative Dermatology, 2003](https://pubmed.ncbi.nlm.nih.gov/12713590/))
- 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/))
- 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/))
- 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/))
- 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/))
- Formulations containing 0.10%, 0.25%, and 0.50% freeze-dried Aloe vera extract increased stratum corneum water content compared with the vehicle in 20 female subjects, while transepidermal water loss was not modified. ([Skin Research and Technology, 2006](https://pubmed.ncbi.nlm.nih.gov/17026654/))
- 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 acne-prone skin better

- Topical nicotinamide plus an antibacterial adhesive agent and zinc-pyrrolidone carboxylic acid combined with adapalene significantly reduced noninflammatory acne lesions by the second week of therapy compared to placebo with adapalene in patients with moderate acne vulgaris. ([The Journal of Clinical and Aesthetic Dermatology, 2020](https://pubmed.ncbi.nlm.nih.gov/32983333/))
- 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/))
- Niacinamide and ferulic acid incorporated in a stable multiple emulsion successfully reduced melanin, sebum, and skin erythema while improving skin elasticity and hydration in human skin compared to a placebo. ([BioMed Research International, 2022](https://pubmed.ncbi.nlm.nih.gov/35342760/))

## 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 your serum as part of your PM routine and start 3x/week before working up to daily use.
- Apply this treatment after cleansing and toner, and before your moisturizer.
- Gently press 2-3 drops of the serum into your skin and let it absorb for a minute.
- Apply the product on clean, dry skin to help manage your breakouts safely.
- Avoid the eye area and do a patch test before your first use.
- Video: https://storage.pora.ai/c879dda8655a61c19d3d8c9ebad6b06d.mp4

## Questions and answers

### How well does 111SKIN Y Theorem Repair Light Serum work for acne-prone skin?

This serum works moderately well for acne-prone skin because niacinamide and aloe vera help balance oil and add moisture, though they do not specifically target breakouts. An acne-prone skin treatment needs targeted ingredients like propolis or zinc PCA that directly clear blemishes while keeping the skin balanced and calm.
Sources: [The Journal of Investigative Dermatology, 2003](https://pubmed.ncbi.nlm.nih.gov/12713590/), [Journal of Cosmetic Dermatology, 2021](https://pubmed.ncbi.nlm.nih.gov/33103316/)

### Which ingredients make this serum a good fit for acne-prone skin?

Niacinamide and aloe barbadensis extract make this serum an average fit for your acne-prone skin by helping balance oil and adding moisture, though it lacks ingredients specifically targeted for breakouts. To work best for this skin type, a treatment needs ingredients like propolis or zinc PCA that directly target acne and blemishes while keeping skin balanced.
Sources: [Clinical Pharmacology, 2018](https://pubmed.ncbi.nlm.nih.gov/30588129/)

### What does Nac Y2 do for acne-prone skin?

NAC Y2 helps calm irritation and supports the skin barrier for acne-prone skin. It is unlikely to clog pores and may reduce redness associated with breakouts. A product for this type of skin needs soothing ingredients and antioxidants to keep it clear and calm.

### What does Niacinamide do for acne-prone skin?

Niacinamide helps acne-prone skin by reducing both inflamed and uninflamed breakouts and calming redness. It is also very helpful for keeping oily skin balanced by cutting down on excess oil production, and it is well tolerated by most people.
Sources: [Journal of Cosmetic Dermatology, 2024](https://pubmed.ncbi.nlm.nih.gov/38299457/), [Cureus, 2024](https://pubmed.ncbi.nlm.nih.gov/38725769/)

### Where does this serum go in a skincare routine for acne-prone skin?

This treatment serum goes in your evening routine after cleansing and before moisturizing. While it is safe and helps with skin repair, acne-prone skin needs products with ingredients specifically targeted for breakouts, blemishes, and acne.

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

Yes, you can use this serum with retinol, applying the treatment after your retinol or as part of your evening routine. It is unlikely to irritate your skin thanks to soothing ingredients like aloe and calendula. Acne-prone skin often benefits from products that specifically target blemishes and breakouts while helping keep pores clear.
Sources: [Journal of Cosmetic Dermatology, 2024](https://pubmed.ncbi.nlm.nih.gov/38102855/), [Clinical Pharmacology, 2018](https://pubmed.ncbi.nlm.nih.gov/30588129/)

### How often should I use this serum?

This serum works well in your evening routine, where you can apply it once a day. For acne-prone skin, a product of this type needs targeted ingredients that actively clear blemishes and breakouts.

### Can this serum clog pores, cause breakouts or purging for acne-prone skin?

This serum is unlikely to clog pores or cause breakouts for your acne-prone skin, as it contains soothing ingredients like aloe and calendula without harsh irritants. However, because it lacks targeted blemish-fighting ingredients, acne-prone skin often does better with a treatment that includes acne-specific active ingredients to actively clear breakouts.
Sources: [Clinical Pharmacology, 2018](https://pubmed.ncbi.nlm.nih.gov/30588129/)

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

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

## Alternatives for acne-prone skin

- [Beauty of Joseon Propolis + Niacinamide Glow Serum](https://lovi.care/skincare/ie/p/beauty-of-joseon/propolis-niacinamide-glow-serum/for/acne-prone-skin) — Superior fit — €14.94 at Amazon
- [Neogen Dermalogy Real Niacinamide 15% Firming Serum](https://lovi.care/skincare/ie/p/neogen-dermalogy/real-niacinamide-15-firming-serum/for/acne-prone-skin) — Superior fit — €52.57 at Amazon
- [SkinCeuticals C E Ferulic](https://lovi.care/skincare/ie/p/skinceuticals/c-e-ferulic/for/acne-prone-skin) — Superior fit — €185.00 at Amazon

## Pairs well with

- Cleanser: [B.LAB Matcha Hydrating Foam Cleanser](https://lovi.care/skincare/ie/p/b-lab/matcha-hydrating-foam-cleanser/for/acne-prone-skin) — Superior fit — €13.40 at Amazon
- Hydrating Toner: [SOME BY MI Snail Truecica Miracle Repair Toner](https://lovi.care/skincare/ie/p/some-by-mi/snail-truecica-miracle-repair-toner/for/acne-prone-skin) — Superior fit — €19.99 at Amazon
- Moisturizer: [Some By Mi Yuja Niacin Brightening Moisture Gel Cream](https://lovi.care/skincare/ie/p/some-by-mi/yuja-niacin-brightening-moisture-gel-cream/for/acne-prone-skin) — Superior fit — €18.99 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/acne-prone-skin
- United Kingdom: https://lovi.care/skincare/uk/p/111skin/y-theorem-repair-light-serum-nac-y2/for/acne-prone-skin
- Ireland: https://lovi.care/skincare/ie/p/111skin/y-theorem-repair-light-serum-nac-y2/for/acne-prone-skin (this page)
- Germany: https://lovi.care/skincare/de/p/111skin/y-theorem-repair-light-serum-nac-y2/for/acne-prone-skin
- France: https://lovi.care/skincare/fr/p/111skin/y-theorem-repair-light-serum-nac-y2/for/acne-prone-skin
- Italy: https://lovi.care/skincare/it/p/111skin/y-theorem-repair-light-serum-nac-y2/for/acne-prone-skin
- Netherlands: https://lovi.care/skincare/nl/p/111skin/y-theorem-repair-light-serum-nac-y2/for/acne-prone-skin
- Spain: https://lovi.care/skincare/es/p/111skin/y-theorem-repair-light-serum-nac-y2/for/acne-prone-skin
- Canada: https://lovi.care/skincare/ca/p/111skin/y-theorem-repair-light-serum-nac-y2/for/acne-prone-skin
- Australia: https://lovi.care/skincare/au/p/111skin/y-theorem-repair-light-serum-nac-y2/for/acne-prone-skin
- Singapore: https://lovi.care/skincare/sg/p/111skin/y-theorem-repair-light-serum-nac-y2/for/acne-prone-skin
- Saudi Arabia: https://lovi.care/skincare/sa/p/111skin/y-theorem-repair-light-serum-nac-y2/for/acne-prone-skin
- United Arab Emirates: https://lovi.care/skincare/ae/p/111skin/y-theorem-repair-light-serum-nac-y2/for/acne-prone-skin