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

**Lovi Fit: Average fit for oily skin.**
Oily Skin Fit: High · Effectiveness: Average · Safety: High.

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

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

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

This fit is calculated for the concerns frequently associated with oily skin: shine, enlarged pores, blackheads, and blemishes. For scores based on a full skin profile (12D face scan, goals, preferences), use the Lovi app.

Works for oily skin; other serums fit it better.

## Why this fit

- Offers moderate benefits for your oily skin, as niacinamide and sodium ascorbyl phosphate help with seboregulation and antioxidant activity, while glycerin and aloe barbadensis extract provide general hydration and soothing effects.
- The presence of acetyl cysteine and niacinamide supports skin barrier resilience, though the formula does not specifically target oily shine concerns.
- The product is safe for your oily skin, with no identified risks of irritation due to the absence of harsh ingredients.

## Fit by skin type

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

- Combined ascorbyl palmitate and sodium ascorbyl phosphate treatment significantly reduced facial sebum secretions in healthy female volunteers compared to a placebo control over 90 days. ([Drug Research, 2017](https://pubmed.ncbi.nlm.nih.gov/27756097/))
- A single application of a moisturizing fluid containing hyaluronic acid 1%, glycerin 5%, and Centella asiatica stem cells extract significantly increased skin hydration by 29% and reduced transepidermal water loss at 24 hours compared to baseline and an untreated control site in twenty healthy women. ([Clinical, Cosmetic and Investigational Dermatology, 2017](https://pubmed.ncbi.nlm.nih.gov/28860834/))
- 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/))
- 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 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/))
- 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 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 oily skin better

- 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 this serum in your PM routine. Start by applying it 3 times a week and build up to daily use if your skin tolerates it well.
- Apply the serum after cleansing and toning, but right before your moisturizer for the best results.
- Gently press 2-3 drops of the serum into your skin. Let it absorb ⏱ for a minute before applying the next product.
- Apply the serum on clean and dry skin since your skin is not sensitive and you want to target oily shine. This helps control excess oil throughout the night.
- Avoid the delicate eye area and do a patch test before using the serum for the very first time.
- Video: https://storage.pora.ai/c879dda8655a61c19d3d8c9ebad6b06d.mp4

## Questions and answers

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

This serum works moderately well for oily skin by helping control oil and soothe the skin, though it does not specifically target oily shine. Treatments that fit oily skin better need ingredients like niacinamide and zinc PCA to manage excess oil and enlarged pores, along with soothing and hydrating extracts.
Sources: [Drug Research, 2017](https://pubmed.ncbi.nlm.nih.gov/27756097/)

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

This serum helps your oily skin with niacinamide and sodium ascorbyl phosphate for controlling oil and providing antioxidants, along with glycerin and aloe extract for soothing hydration. To be a top fit for oily skin, a treatment needs ingredients like niacinamide, zinc pca, and ferulic acid that specifically target excess shine and pores while keeping the skin barrier healthy.
Sources: [Drug Research, 2017](https://pubmed.ncbi.nlm.nih.gov/27756097/), [Clinical, Cosmetic and Investigational Dermatology, 2017](https://pubmed.ncbi.nlm.nih.gov/28860834/)

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

Nac Y2 acts as an antioxidant and helps calm oily skin, though its exact effects depend on the specific formulation. A product for oily skin typically needs lightweight, balancing ingredients that soothe without feeling heavy.
Sources: [Indian Journal of Dermatology, Venereology and Leprology, 2018](https://pubmed.ncbi.nlm.nih.gov/30246706/), [The Journal of Dermatology, 2025](https://pubmed.ncbi.nlm.nih.gov/38923010/)

### What does Niacinamide do for oily skin?

Niacinamide helps balance oily skin by significantly reducing excess oil production and shine. It is well tolerated and may improve skin texture without clogging pores.
Sources: [Journal of Cosmetic and Laser Therapy, 2006](https://pubmed.ncbi.nlm.nih.gov/16766489/), [Antioxidants, 2021](https://pubmed.ncbi.nlm.nih.gov/34439563/)

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

This treatment goes in the evening routine, after cleansing and toning and before moisturizing, for simplicity and extra safety around sun exposure. It works for your oily skin through ingredients like niacinamide and glycerin, though an oily skin product of this type needs stronger oil-controlling ingredients to manage shine.

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

You can use this treatment with retinol, applying the treatment first and following with your retinol once it absorbs. It is safe for your oily skin and is unlikely to cause irritation.

### How often should I use this serum?

You can use this serum in your evening routine, applying it after your cleansing toner and before your moisturizer. Oily skin works best with a treatment that specifically targets excess oil and shine while balancing hydration.

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

This serum is unlikely to cause breakouts or clog pores on oily skin, as it has a safe profile with no harsh ingredients that typically cause irritation. However, because it does not specifically target oily shine or extra oil, an oily skin routine often needs lightweight, oil-balancing ingredients like salicylic acid or zinc to truly help keep pores clear.

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

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

## Alternatives for oily skin

- [Beauty of Joseon Propolis + Niacinamide Glow Serum](https://lovi.care/skincare/au/p/beauty-of-joseon/propolis-niacinamide-glow-serum/for/oily-skin) — Superior fit — A$16.95 at Amazon
- [Neogen Dermalogy Real Niacinamide 15% Firming Serum](https://lovi.care/skincare/au/p/neogen-dermalogy/real-niacinamide-15-firming-serum/for/oily-skin) — Superior fit — A$52.32 at Amazon
- [NEOGEN DERMALOGY REAL VITA C SERUM](https://lovi.care/skincare/au/p/neogen-dermalogy/real-vita-c-serum/for/oily-skin) — High fit — A$50.60 at Amazon

## Pairs well with

- Cleanser: [CeraVe Foaming Facial Cleanser](https://lovi.care/skincare/au/p/cerave/foaming-facial-cleanser/for/oily-skin) — Superior fit — A$13.99 at Amazon
- Hydrating Toner: [SOME BY MI Snail Truecica Miracle Repair Toner](https://lovi.care/skincare/au/p/some-by-mi/snail-truecica-miracle-repair-toner/for/oily-skin) — Superior fit — A$34.66 at Amazon
- Moisturizer: [COSRX Oil-Free Ultra-Moisturizing Lotion with Birch Sap](https://lovi.care/skincare/au/p/cosrx/oil-free-ultra-moisturizing-lotion-with-birch-sap/for/oily-skin) — Superior fit — A$22.99 at Amazon

## Where to buy

- Amazon.com.au: A$397.77 (https://www.amazon.com.au/dp/B00U3CWDUK?tag=lovi-care-web-product-22&linkCode=osi&th=1&psc=1)
Prices checked 2 Nov 2026.

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