- Thermal protection up to 230°C for hair dryers and straighteners
- Frizz control maintained for up to 10 washes
- 5% keratin formula that seals the fiber in depth
L'Oréal Professionnel Paris
A professional keratin serum that smoothes, disciplines and protects your hair for up to 10 washes - for mirror-like, light and silky hair every day.
Properties of Keratin Alpha Sleek serum from L'Oréal
- Thermoactive formula which seals the hair fiber in depth
- Frizz and volume control maintained for up to 10 washes
- Thermal protection up to 230°C for use with hair dryers or straighteners
- Anti-humidity shield effective up to 80% ambient humidity
- Amplified results as a complete routine: gentleness and discipline for up to 2 weeks
- No artificial colors, no alcohol for respectful care of the hair fiber
- Suitable for all hair types, including colored or weakened hair
L'Oréal Keratin Alpha Sleek serum: a professional gesture, a mirror result
With age, hair can become more porous, more sensitive to humidity and more difficult to manage on a daily basis. The Keratin Alpha Sleek Mirror Serum was designed to meet these needs precisely: its thermoactive formula, enriched with 5% keratin, acts as a real sealant on the internal structure of the hair. By penetrating the fiber, it reconstitutes the natural binder of keratin, restores the curve and suppleness of each strand, and creates a smooth surface which reflects light like a mirror.
Its application is a real care ritual. A few drops are enough to nourish and wrap the lengths and ends. The heat from the hair dryer or straightener activates the formula and increases its effects: frizz fades, excessive volume is tamed, and hair regains a silky feel that lasts. For even more lasting results, combined with the complete routine of the Série Expert Alpha Sleek range, this serum lastingly transforms hair texture for up to two weeks, even in humid weather.
What distinguishes this serum from classic treatments is the precision of its development by the L'Oréal Professionnel laboratories: a controlled concentration, a light texture which does not overload fine hair, high-performance thermal protection at 230°C, and a refined formula, without alcohol or artificial colorings. A salon product, available to enhance your beauty ritual at home.
Also find all our shampoos, care and styling to compose your ideal hair routine and prolong the benefits of your serum over time.
We love : Hair visibly smoother, shinier, more manageable even on humid days.
- Shake the bottle before use
- Distribute the product between your palms: 2 to 4 sprays for fine hair, 6 to 8 for thick hair
- Apply to clean, damp hair, from mid-lengths to ends, massaging gently to ensure the treatment is fully absorbed.
- Do not rinse
- Blow dry or use a straightener to activate the thermoactive formula and enhance the result
| Features | Values |
|---|---|
| Capacity | 50ml |
| Hairdressing ranges | Keratin Alpha Sleek |
| Brand | L'Oréal Professionnel Paris |
| Treatment | Smoothing |
| Hair type | All hair types |

| SKU | Designation | |
|---|---|---|
|
072000300238 | Sleek Alpha Keratin Mirror Serum Série Expert |