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111SKIN Y Theorem Repair Light Serum NAC Y2 for dry skin

Rated by Lovi · Unbiased, science-based skincare AI trained on real user outcomes

111SKIN Y Theorem Repair Light Serum NAC Y2

Average

  • AverageDry Skin Fit
  • AverageEffectiveness
  • HighSafety

Works for dry skin; other serums fit it better.

This fit is calculated for the concerns frequently associated with dry skin: flakiness, tightness, dehydration, fine lines, and wrinkles. For scores and recommendations based on your full skin profile, including your 12D face scan results and any goals or preferences you have, please use the Lovi app.

Page built Nov 8, 2026How the Fit score works

Lovi Assistant explains

  • Offers moderate suitability for your dry skin, as glycerin and panthenol provide humectant action to attract moisture, but it lacks sufficient emollient ingredients like apricot kernel oil to fully address dryness.
  • The serum provides excellent skin repair due to niacinamide and acetyl cysteine, enhancing barrier resilience, and offers general hydration benefits from aloe barbadensis extract.
  • The safety profile is excellent, with no risks of irritation for your dry skin due to the absence of prohibited or harsh ingredients.

How to apply

  • Apply this serum PM, starting 3×/week and working up to daily use as your skin adjusts.
  • Place the serum after cleansing and toner, but right before your moisturizer.
  • Gently press 2-3 drops of the serum into your skin and let it absorb for a minute.
  • Apply the serum on slightly damp skin to help lock in extra moisture.
  • Avoid the eye area and do a patch test before your first use.

People Say

★4.2Overall rating based on 200+ reviews

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.

Highlights

  • Lightweight & fast-absorbing Mostly Mentioned
    • “absorbs almost instantly”
    • “water-like texture”
    • “not sticky or tacky”
    • “perfect for oilier skin”
  • Extremely expensive Mostly Mentioned
    • “not worth the money”
    • “terrible for money”
    • “understandable to balk at the price”
    • “overpriced for what it is”
  • Hydrating & plumping Often Mentioned
    • “skin was baby-soft”
    • “beaming with light”
    • “hydrates and plumps”
    • “woke up looking radiant”
  • Soothing & healing Often Mentioned
    • “calms my very sensitive skin”
    • “heals and evens out acne scars”
    • “reduced redness”
    • “great for post-procedure”
  • Good for oily skin Sometimes Noted
    • “didn't leave me feeling greasy”
    • “perfect for oilier skin types”
    • “balanced my oily skin”
  • Lack of visible results Sometimes Noted
    • “just ok”
    • “none of them did anything”
    • “didn't see a difference”
    • “all hype”
  • Strong fragrance Sometimes Noted
    • “smells absolutely revolting”
    • “wish it wasn't fragranced”
    • “strong floral scent”
    • “smell is too much”
  • Potential irritation Rarely Noted
    • “winced when applied”
    • “not for sensitive skin”
    • “caused a reaction”

Sources: lovi.care, sephora.co.uk, spacenk.com, cultbeauty.co.uk, dermstore.com, neimanmarcus.com, and more

Questions and answers

How well does Y Theorem Repair Light Serum work for dry skin?

This serum offers moderate suitability for dry skin because glycerin and panthenol draw in moisture, but it lacks enough rich, softening ingredients to fully address dryness. A treatment for dry skin needs rich, softening ingredients and skin-restoring additions like ceramides, peptides, or propolis to deeply nourish and maintain a healthy glow.

Clinical, Cosmetic and Investigational Dermatology, 2017The Journal of Dermatological Treatment, 2017

Which ingredients make this serum a good fit for dry skin?

Glycerin and panthenol help this serum fit dry skin by drawing in moisture, while niacinamide and acetyl cysteine strengthen the skin barrier. To suit dry skin best, a product of this type needs rich softening ingredients like apricot kernel oil alongside soothing hydrators, antioxidants, ceramides, and peptides.

Clinical, Cosmetic and Investigational Dermatology, 2017The Journal of Dermatological Treatment, 2017

What does Nac Y2 do for dry skin?

NAC Y2 acts as an antioxidant that helps soothe and protect dry skin. It supports skin comfort and is unlikely to cause irritation when used in your daily routine.

Indian Journal of Dermatology, Venereology and Leprology, 2018The Journal of Dermatology, 2025

What does Niacinamide do for dry skin?

Niacinamide helps dry skin by strengthening the skin barrier, increasing hydration, and reducing water loss. It supports ceramide production and helps keep the surface smooth and calm. This ingredient tends to be very well tolerated and is unlikely to irritate dry skin.

Journal of Cosmetic Dermatology, 2004Journal of Cosmetic Dermatology, 2026

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

This serum goes in your evening routine, applied after cleansing and before your moisturizer. It is unlikely to cause irritation on dry skin, but dry skin of this type needs rich softening ingredients like apricot kernel oil to fully lock in moisture.

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

You can use this treatment with retinol by applying the serum first in your evening routine, followed by your retinol and moisturizer. This product is unlikely to irritate dry skin due to its safe ingredients, but dry skin needs extra rich smoothing ingredients like apricot kernel oil to truly thrive.

How often should I use this serum?

This treatment serum works best in your evening routine for simplicity and extra safety around sun exposure. Dry skin needs a product of this type to include rich smoothing ingredients like apricot kernel oil to fully address dryness.

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

This serum is unlikely to cause breakouts or clog pores for dry skin, as its safety profile is excellent and it lacks harsh ingredients. It helps keep skin calm and hydrated, though a product for this skin also needs richer, softening oils to fully lock in moisture.

Clinical, Cosmetic and Investigational Dermatology, 2017The Journal of Dermatological Treatment, 2017

Is this serum fragrance-free and alcohol-free?

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

What the research says

  • 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

  • A new topical panthenol-containing emollient significantly improved transepidermal water loss reduction, stratum corneum hydration, and intercellular lipid lamellae length compared with control in healthy subjects without negatively impacting bacterial viability.

    The Journal of Dermatological Treatment, 2017

  • Topical dexpanthenol acts as a moisturizer, improves stratum corneum hydration, accelerates wound healing and epidermal regeneration, reduces erythema, and improves symptoms of skin irritation compared to vehicle or no pretreatment.

    American Journal of Clinical Dermatology, 2002

  • 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

  • A panthenol-enriched mask significantly decreased erythema and hyperpigmentation, increased sebum and stratum corneum moisture, and reduced transepidermal water loss compared to a saline dressing in 60 subjects undergoing facial laser treatment.

    Journal of Cosmetic Dermatology, 2025

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

Why other serums fit dry skin better

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

Behind this fit score

Lovi calculates every fit score from the full ingredient list with brand-independent rules our 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.

  • Nadia Kapleva, MS

    Nadia Kapleva, MS

    Co-founder, Medical Director

    Cosmetic chemist, cosmetologist, aesthetic products developer

  • Alexey Shagraev, PhD

    Alexey Shagraev, PhD

    Co-founder, CEO and CTO

    PhD in computer science, 3x US patent holder, ex-Google, ex-Yandex

  • Dr. Sofía Perea Pérez, MD, MSc

    Dr. Sofía Perea Pérez, MD, MSc

    Medical Board

    Aesthetic medicine practitioner, MSc in Longevity and Anti-Aging Medicine

  • Aishani Shah, MD

    Aishani Shah, MD

    Medical Board

    Specialist dermatologist, MBBS, MD, IFAAD

  • Asya Zubkova, MS

    Asya Zubkova, MS

    Medical Board

    Cosmetic chemist, SCS, IFSCC member

  • Hanna Kurets, MD

    Hanna Kurets, MD

    Medical Board, Medical Advisor

    Dermatology MD

  • Elina Nazarenko, MD

    Elina Nazarenko, MD

    Medical Board

    Dermatology and diagnostic consultant

  • Victoria Derkova, MS

    Victoria Derkova, MS

    Medical Board

    Cosmetic chemist, cosmetic development technologist

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How does it fit your skin?

Scan your face, then any product: Lovi shows how well it fits you and what fits even better.

QR code: get the Lovi app
Download on theApp Store Get it onGoogle Play