nail care kit
Day & Night Duo

Regular price
$25
Regular price
$30
Sale price
$25
201 reviews

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The day & night routine for soft, damaged-looking nails  — an express treatment designed to strengthen, nourish, and restore. This routine includes:

  • The Keratin Booster, a 10% keratin concentrated serum to instantly help repair fragile nails
  • The S.O.S. Nail Mask, an overnight care to intensely hydrate nails

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4.6/5 – Trusted by 160,000+ customers globally

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Description

The day & night routine
7 days to visibly repair soft and damaged-looking nails, with the combined action of two expert care treatments

Day care - The Keratin Booster:
The miracle nail strengthening serum that instantly hardens and regenerates soft and damaged-looking nails.

10% concentrated care formula:

  • Plant-based Keratin: Intensely nourishes fragile nails
  • AHA & Gluconolactone: gently exfoliate the nail plate
  • Silicon: helps strengthen the nail
  • Biotin (Vitamin B8): helps harden and fortify the nail
  • Vitamin C: protects the nail from external aggressions

Proven visible results:

  • 85% found their nails harder*
  • 81% found their nails stronger*
  • 81% found their nails were less likely to split*

Its fluid texture is instantly absorbed, leaving the nail with no greasy or sticky finish.

*Clinical test conducted under dermatological supervision on 25 individuals after two weeks of use.

Night care - The S.O.S. Nail Mask:
The overnight mask intensely hydrates very damaged-looking nails. Its unique formula, highly concentrated in emollients and fortifying agents, forms a protective film on the nail surface to boost cell repair overnight.

Proven visible results:

  • 80% found their nails more hydrated**
  • 75% found their nails harder**
  • 75% found their nails stronger**

**Test conducted on a panel of 20 people over 14 days.

How-to-use the Day & Night Routine?

Your 7-day care routine, to repair soft and damaged-looking nails:

  • Day care: On bare nails, apply the Keratin Booster 1 to 3 times a day using the brush. Let it dry until fully absorbed.
  • Night care: On bare nails, apply the S.O.S. Mask 2 to 3 nights a week in a thick layer. Let it dry. The next morning, remove it by peeling it off or washing with soapy water.


Pro tip
✨

To complete the routine, nourish the cuticles daily with the Nourishing Nail Pen.

Sustainable Packaging

Green S.O.S Base Coat

Glass Bottle: Emptied, cleaned and dried bottles can either be reused or placed in a recycling bin seperate from other materials to avoid contamination. If your local manicapality does not accept glass for recycling, bottles can be brought to a collection center. No need to remove labeling.

Plastic Cap (Plastic-type #5 - Polypropylene): Clean and remove cap from brush attachment and place in recycling bin or bring to a local collection center.

Nail Brush (Plastic-type #4 - Low Density Polyethylene): Clean and remove cap from brush and place in recycling bin or bring to a local collection center.

Label: No need to remove label as glass recycling processes will remove any labelilng

Box (Kraft Paper Box): Paper box can be unfolded and added to paper recycling bin or brought to a local collection center, Kraft paper box can also be added to any compost bin.

As always, verify your local municipality's recycling regulations and procedures and for more information please go to berecycled.org/search or search.earth911.com

Green Oil

Glass Bottle: Emptied, cleaned and dried bottles can either be reused or placed in a recycling bin seperate from other materials to avoid contamination. If your local manicapality does not accept glass for recycling, bottles can be brought to a collection center. No need to remove labeling.

Glass Dropper: Remove product completely and seperate from lid. Once emptied, cleaned and dried, glass can be placed in a recycling bin seperate from other materials to avoid contaimination. If your local manicapality does not accept glass for recycling, glass dropper can be brought to a collection center.

Plastic Lid (Plastic type #5: Polypropylene and Nirtile): Seperated, cleaned and dried lid attachment and pressure squeeze attachment can be added to recycling bin seperate from other materials to avoid contaimination or taken to a collection center.

Label: No need to remove label as glass recycling processes will remove any labelilng

Box (Kraft Paper Box): Paper box can be unfolded and added to paper recycling bin or brought to a local collection center, Kraft paper box can also be added to any compost bin.

As always, verify your local municipality's recycling regulations and procedures and for more information please go to berecycled.org/search or search.earth911.com

Ingredients (INCI)

Super ingredients

INCI list

Nail Strengthening Serum:
ALCOHOL DENAT., AQUA (WATER), PRUNUS ARMENIACA (APRICOT) KERNEL OIL, DIMETHYL SULFONE, PARFUM (FRAGRANCE), GLYCOLIC ACID, POLYACRYLATE CROSSPOLYMER-6, PHAEODACTYLUM TRICORNUTUM EXTRACT, HYDROLYZED CICER SEED EXTRACT, CHENOPODIUM QUINOA SEED EXTRACT, LENS ESCULENTA (LENTIL) SEED EXTRACT, PENTYLENE GLYCOL, GLUCONOLACTONE, ISOPROPYL ALCOHOL, ACETYL CYSTEINE, MAGNESIUM ASCORBYL PHOSPHATE, BIOTIN

96,5% natural origin ingredients*

S.O.S. Nail Mask:
AQUA (WATER), ALCOHOL DENAT., POLYVINYL ALCOHOL, PANTHENOL, PARFUM (FRAGRANCE), ALCOHOL, TRIS(TETRAMETHYLHYDROXYPIPERIDINOL) CITRATE, CI 14700 (RED 4)

80,5% ingredients from natural origins*

*Calculation based on the international ISO 16128 standards.

The Manucurist Day  Night Duo, featuring two nail treatments, is displayed side by side on a pale background.
Two bottles of Manucurist’s Day  Night Duo are shown on a pink background. Text highlights clinical results: 85% saw harder nails and 80% observed more hydration after using this nail treatment and keratin serum.
Side-by-side images show a finger’s dry, peeling cuticles before and smooth, healthy cuticles after using Manucurist Day  Night Duo. Each image is labeled to highlight the transformation.
A close-up of a person applying Manucurist&
Two clear Manucurist Day  Night Duo nail care bottles with white caps are set against a soft pink background. The duo includes a keratin serum booster and Masque S.O.S nail mask, both for effective nail treatment.
Three manicure products for nail care on a light pink background: a square bottle of Manucurist Nail Strengthening Serum, a square bottle of Masque S.O.S. overnight nail mask, and a tube of Concentré perfecteur.
Day  Night Duo by Manucurist: two luxurious manicure treatments presented on a light beige background, representing premium nail care from the esteemed Parisian brand.

Day & night routine for soft, damaged-looking nails

Strengthens and regenerates
nails

A simple black outline of a magic wand with a star at the tip, surrounded by small lines representing sparkles or magical effects, on a light gray background.

Repairs fragile
nails

Simple black line drawing of an open right hand facing upward with three lines above it, suggesting receiving, offering, or presenting something.

Intensely hydrates
the nail plate

FAQs

Les questions les plus fréquemment posées par nos utilisatrices et notre communauté !

Can I use the Keratin Booster with a base coat?

The Keratin Booster should be applied on bare nails only. If you wish to use a base coat, apply it after the care, once the nail has been cleansed.

Can I use the Keratin Booster several times a year?

Yes, you can repeat the care several times a year. It’s recommended to take a break between each care and monitor your nail’s condition over time.

If I want to apply more treatment base coat, should I remove the old coat first?

When using a treatment base coat, there's no need to remove the previous coat.

Can I apply the Keratin Booster under Green™ or Green Flash™ polish?

Yes, but it’s essential to cleanse the nail surface after the product has been absorbed to ensure optimal polish adhesion.

 

Our customers talk about us!

Our reviews are collected 28 days after any purchase and these are the reviews of verified buyers only

Overall rating: 4.6453204 / 5 from 203 reviews.

AI Generated Review Summary

Day & Night Duo offers a dual-action routine for damaged nails, featuring a keratin booster for immediate strength and an overnight mask for hydration. Users report varied results, with some experiencing improved nail health and others noting dryness.

Summary topics

  • Keratin Booster Effectiveness (10%): It was highlighted by customers that the keratin booster quickly makes nails stronger and more solid after a few applications.
  • Nail Health (42%): The feedback is varied, with some users reporting stronger and healthier nails, while others experienced dryness and peeling.

Review topics: ["smell","feel","look","problem","improvement","absorbs","nails","result","mask","treatment","duo","difference","keratin booster","effect","care","routine","application","polish","become","combo","works","use","damage","film","grow","ridges","drying","shine","splitting","serum"].

Review highlights

  • "Keratin Booster absorbs very quickly and leaves no film on the nails." — Christine S.
  • "I use them in addition to Glossy Booster and my nails look and feel so much stronger, healthier, and shinier." — Antoinette
  • "Nails look healthy again" — Mary G.

Reviews

Assez bluffant : le "kératine

"Assez bluffant : le "kératine booster" disparaît immédiatement, comme bu par les ongles. Et le masque est la toute dernière chose à faire, avant de se coucher. J'attends beaucoup de ces 2 produits ! Et il me semble bien que mes ongles ont meilleure apparence ✌️"

— Catherine H. (5/5)

Incredibile, mia figlia l'ottava con

"Incredibile, mia figlia l'ottava con le unghie deboli e che si sfaldavano da ormai due anni. In 3 settimane di trattamento ha risolto. Pensavo migliorasse, non risolvesse. . . Sono stupita. Ora lo fa ogni tanto, giusto per tenerle curate"

— Silvia C. (5/5)

Tenía las uñas muy deterioradas,

"Tenía las uñas muy deterioradas, se me abrían en capas y se me rompian. He conseguido que me crezcan sin q se rompan tanto. Se ven más sanas."

— Esperanza R. (5/5)

Really impressed with this duo

"Really impressed with this duo of treatments - using them daily & while it’s taking time my nails feel smoother & tougher although nails still slow to grow"

— Jill H. (4/5)

Fantastici entrambi! Sia la maschera

"Fantastici entrambi! Sia la maschera che il rafforzamento di keratina🙏❤️"

— Alessandra P. (5/5)

Excellente routine de soins. Le

"Excellente routine de soins. Le masque sos: résultat bluffant"

— Marie-Christine J. (5/5)

Bonjour, j’ai beaucoup aimé car

"Bonjour, j’ai beaucoup aimé car produits très efficaces. Je recommande vivement"

— davidclaire2103@gmail.com ‎. (5/5)

These were not sent. It

"These were not sent. It took 6 emails etc to get a reply. In the meantime I punched another product. I asked for a refund. I was promised the Green Oil free to make up for the problems. This of course did not arrive either. I have not as yet used the product so cannot comment on if it works."

— bishosborne@gmail.com ‎. (5/5)

C'est soins sont supers. Facile

"C'est soins sont supers. Facile a appliquer. Je les recommande les yeux fermés"

— Laure D. (5/5)

Mes ongles ont changés du

"Mes ongles ont changés du tout au tout !genial"

— Charlotte M. (5/5)

Q&A