KERASYS Serums
KERASYS Serums are concentrated leave-in actives applied after washing to address specific hair concerns without rinsing. The 15-SKU range covers argan oil (shine and frizz), ceramide repair (Keramide Extreme Damage), advanced ampoule serums (10X Repair and Moisture), a curl-defining serum, a total recovery serum, and a scalp essence-each delivering a targeted active to where the hair needs it most between wash sessions.
By Skinsli editorial Updated
Buying guide
KERASYS Hair Serums: Which One to Use and How
KERASYS hair serums are leave-in concentrated formulas applied after washing to deliver specific actives without rinsing. Unlike in-shower treatments, serums stay on the hair and scalp through drying and styling, providing ongoing active delivery between washes. This guide covers each KERASYS serum variant, what it does, and how to apply it correctly.
What a Hair Serum Does (and How It Differs from a Treatment)
Hair serums and in-shower treatments address the same concerns-damage, dryness, frizz-but through different mechanisms and at different times in the routine. In-shower treatments deposit actives when the cuticle is slightly open from warm water and washing. Serums deposit actives on towel-dried or dry hair, where the cuticle is more closed and the product stays on the surface longer.
This means serums are better at providing continuous protection through the day (heat protection, humidity resistance, anti-frizz) and at delivering actives that benefit from longer contact time (ceramide, scalp essences). Treatments are better at short-term intensive loading per wash session. For maximum active delivery, use both: treatment at the wash step, serum as a leave-in after drying.
Argan Oil Hair Serum 100 ml
The largest serum format in the range. Argan oil's oleic acid and vitamin E profile provides surface smoothing, frizz reduction, shine, and light thermal protection. Applied as a lightweight leave-in:
- On damp hair before blow-drying: 2-3 drops worked through mid-lengths and ends provides thermal protection and helps the hair dry smoother.
- On dry, styled hair: 1 drop smoothed over the surface controls flyaways and adds shine without making hair look greasy.
The 100 ml size reflects that argan serum is used daily or near-daily. It is one of the most versatile formats in the KERASYS serum range and works across most hair types.
Ceramide Serums: Keramide Extreme Damage Range
Three ceramide serum variants address different intensity levels of structural damage:
- Keramide Extreme Damage Clinic Serum 70 ml: current standard-concentration ceramide leave-in for moderately damaged hair.
- Keramide Extreme Damage Rich Serum 70 ml (and the identically-formulated Keramide Extreme Damage Serum Rich 70 ml): heavier ceramide and emollient loading for coarse, thick, or severely damaged hair.
- Advanced Keramide Rich Hair Serum 70 ml: highest ceramide concentration in the range, for hair with serious structural damage that hasn't responded to standard-strength ceramide products.
Apply 2-4 drops to towel-dried mid-lengths and ends. The ceramide serums work progressively-each application deposits a small amount, and the cuticle-barrier improvement accumulates over 6-8 weeks of consistent use.
Advanced 10X Ampoule Serums: Repair and Moisture
The Advanced 10X Ampoule Serums (80 ml each) carry a 10X concentration of repair or moisture actives relative to standard KERASYS serums. Two variants:
- Advanced 10X Repair Ampoule Serum: focused on structural damage repair-protein-loss, cuticle integrity, breakage reduction. Best for chemically damaged or heavily heat-styled hair.
- Advanced 10X Moisture Ampoule Serum: focused on hydration and moisture retention. Best for hair that is dry but not structurally damaged-coarse hair in dry climates, naturally low-moisture hair types.
The 10X concentration means a smaller amount goes further than a standard serum-start with 2 drops and build up if needed. Over-application of concentrated serums can make hair look heavy or greasy.
Advanced 10X Curling Serum 150 ml
The Curling Serum is the only styling-focused product in the KERASYS serum range. At 150 ml it is larger than the other serums, reflecting its role as a styling product used at each session rather than a treatment applied in drops. Key functions:
- Defines and separates curls and waves rather than smoothing them flat.
- Reduces frizz within the curl pattern without making curls stiff or crunchy (unlike gel-type curl definers).
- Provides humidity resistance so the curl definition holds in moist conditions.
Apply to wet or damp hair after washing, section by section through the curls, then air dry or diffuse. Do not rub or scrunch after application-let the serum set the curl as the hair dries. For fine curls, use sparingly; for thick or dense curl patterns, more product is needed for full coverage.
Advanced Total Recovery Serum 80 ml
The Total Recovery Serum is a comprehensive multi-benefit formula rather than a single-target product. It combines repair actives, moisture-binding agents, and surface-coating ingredients in a serum format designed to address multiple damage signs simultaneously. It is suited for hair with overlapping issues-damaged and dry, or dry and frizzy-where targeting a single concern would leave others unaddressed.
Apply to towel-dried mid-lengths and ends as a daily leave-in. The broad-spectrum formula makes it a good daily maintenance serum for anyone who doesn't want to choose between the Repair and Moisture ampoule variants.
Scalp Spa Scalp Essence Serum 70 ml
The only scalp-targeted product in the KERASYS serum range. Scalp essences are applied directly to the scalp (not to the lengths) and absorbed without rinsing-they function like a toner or essence in skincare, delivering actives directly to the follicle environment. The Scalp Spa Essence focuses on scalp vitality and is appropriate for people experiencing scalp dryness, mild irritation, or thinning at the scalp level.
Application method: part the hair in sections, apply 1-2 drops per section directly to the scalp, and massage in with fingertips. Do not apply to the hair lengths. Use after washing and before any leave-in applied to the lengths. Can be used morning or evening on non-wash days as well for sustained scalp-level active delivery.
Using Multiple KERASYS Serums Together
If you want to layer multiple serums, apply them in order from lightest to heaviest and from scalp to ends:
- Scalp Spa Essence: applied to scalp first on parted sections. Does not interfere with any other product.
- Ampoule serum (Repair or Moisture 10X): heavier formula applied to mid-shaft and ends next.
- Ceramide serum or Total Recovery: can be applied over the ampoule layer, or on alternate days.
- Argan Oil Serum: lightest or used alone as a finishing step-last in the sequence if layering.
In practice, using two serums at once is sufficient for most hair types. Overloading with multiple serums at every session adds unnecessary weight and can cause buildup on fine hair.
FAQ
Frequently asked questions
FAQ
Frequently asked questions
Do I need both a KERASYS in-shower treatment and a serum, or is one enough?
For most hair types, either product alone provides benefit. Using both gives complementary active delivery: the in-shower treatment loads actives at the wash step when the cuticle is open, and the serum keeps delivering between washes. For moderately damaged or dry hair, a treatment alone is sufficient. For significantly damaged hair or when you want ongoing frizz control and protection through the day, adding a serum is worth it. Start with one product and add the other if you feel your hair needs more support.
Is the KERASYS Advanced 10X Ampoule Serum too strong to use every day?
The 10X Repair Ampoule Serum is safe for daily use-the concentrated actives are repair and conditioning agents, not anything that over-accumulates harmfully. However, a very small amount (2 drops) is sufficient per session; more does not provide additional benefit and can make hair look heavy or greasy. Apply 2 drops to towel-dried mid-lengths and ends daily or at each wash session, and no more.
Can the KERASYS Advanced 10X Curling Serum be used on wavy hair, not just curly?
Yes-the Curling Serum works for natural waves as well as curls. It defines and separates the wave or curl pattern while reducing frizz, without creating a hard or crunchy hold. Apply to wet or damp hair and allow to air dry without disturbing the wave pattern as it sets. Fine waves may need a small amount to avoid the serum weighing the wave down.
How do I use the KERASYS Scalp Spa Scalp Essence Serum correctly?
Part hair in sections and apply 1-2 drops directly to the scalp per section, not to the hair strands. Massage in gently with your fingertips. No rinsing needed. Apply after washing and towel-drying. The scalp essence can also be used on non-wash days if your scalp feels dry or irritated-just apply to a dry scalp and massage in. Do not apply to the hair lengths; this product is formulated for the scalp skin, not the hair shaft.
When should I choose the Keramide Extreme Damage Rich Serum over the standard Serum?
Choose the Rich Serum for thick, coarse, or very porous hair that absorbs products quickly and still feels dry or rough after applying a standard serum. The Rich version has a heavier emollient and ceramide loading that provides more noticeable softness and frizz reduction for dense hair types. For fine or medium hair, the standard Clinic Serum is a better fit-the Rich version may feel too heavy and could flatten fine hair with regular use.
Is the KERASYS Argan Oil Hair Serum safe to use every day?
Yes-argan oil serum is designed for daily leave-in use. Use 2-3 drops on damp hair before blow-drying, or 1 drop on dry styled hair as a finishing step. Daily use does not cause buildup for most hair types because argan oil absorbs well without leaving a heavy residue. If you notice hair looking greasy, reduce the amount per application rather than stopping use.
Who is the KERASYS Advanced Total Recovery Serum designed for?
The Total Recovery Serum is designed for hair with multiple overlapping concerns-for example, hair that is both damaged and dry, or dry and prone to frizz. Rather than targeting one issue precisely (like the Repair Ampoule for damage, or the Moisture Ampoule for dryness), Total Recovery provides a broad-spectrum approach. It works well as a daily all-in-one maintenance serum for people who want a single leave-in rather than two separate targeted products.
Can I apply KERASYS hair serums to my scalp?
Only the Scalp Spa Scalp Essence Serum is designed for scalp application. All other KERASYS serums (Argan Oil, Ceramide, Ampoule, Curling, Total Recovery) should be applied from mid-shaft to ends only. Applying a leave-in hair serum to the scalp can cause follicle-level buildup, accelerate scalp oiliness, and counteract the scalp-care work from your shampoo. The one exception is the Scalp Spa Essence, which is formulated specifically for scalp-level delivery.
How quickly will a KERASYS serum make a visible difference in my hair?
Surface effects (frizz reduction, shine, smoother texture) are noticeable from the first or second application. Structural improvement from the ceramide serums (stronger hair, less breakage) takes 6-8 weeks of consistent use because these changes require multiple growth and cuticle-reconstruction cycles to become visible. The Argan Oil serum's shine and frizz benefits are immediate; the Keramide serums' repair benefits are cumulative.
Are KERASYS serums shipped sealed to prevent leaking?
Yes-all KERASYS serums are shipped in sealed bottles with protective closures. The small formats (70-80 ml) are compact and travel-friendly once open. The 100 ml Argan Oil Serum and 150 ml Curling Serum ship as standard liquid personal care products. No restricted-shipping classification applies to these formulas. Standard delivery to US addresses takes 5-10 business days.