Redken Extreme Length Leave-In Treatment — Biotin Leave-In for Hair Growth, Seals Split Ends & Reduces Breakage

Redken Extreme Length Leave-In Treatment is a biotin- and soy-protein-infused leave-in that strengthens fragile hair, seals split ends, and helps reduce breakage so strands can grow longer and healthier-looking.

Designed by the professional haircare brand Redken, this lightweight leave-in treatment is part of the Extreme Length system and targets weak, damaged hair. It combines Redken's Length Care Complex with biotin and soy protein to reinforce the hair fiber, smooth the cuticle, and improve manageability and shine without weighing hair down. Use it after washing or as a targeted repair step to reduce friction from brushing and support longer-looking hair.

How does this leave-in help hair resist breakage?

The formula strengthens hair along the root, core and tip to lower everyday breakage from styling and brushing. Protein and biotin work to fortify weakened areas while the sealer action smooths cuticle edges that lead to splits and snapping.

• Biotin and soy protein reinforce strand structure.
• Cuticle-smoothing ingredients reduce friction and tangling.
• Lightweight leave-in texture conditions without heaviness.
• Designed to integrate into a system for best results (shampoo, conditioner, treatment).

Will it actually reduce visible split ends and make hair longer?

While no topical product can fuse fully broken ends back together, this treatment seals and smooths split edges to reduce the appearance of split ends and help prevent new ones from forming. When used consistently as part of the Extreme Length regimen, it supports healthier hair surfaces so strands can retain length more effectively.

• Seals and smooths split ends for less visible fraying.
• Helps prevent future breakage that shortens hair length.
• Improves manageability so you can detangle with less stress on strands.

How should I use it for best results?

Apply to towel-dried hair after shampooing and conditioning, concentrating on mid-lengths and ends. Comb through to distribute, then style as usual; no need to rinse. For targeted repair, you can use a small amount on dry hair to tame flyaways and smooth split edges between washes.

• Use on damp hair after cleansing and conditioning.
• Work a quarter-sized amount through lengths and ends; comb to distribute.
• Style regularly—reapply sparingly on dry hair for touch-ups.
• Best combined with Extreme Length shampoo and conditioner for optimal reduction in breakage.

Is it suitable for my hair type and color-treated hair?

The leave-in is formulated for weak, damaged, or fragile hair but works on most hair types that need strengthening and split-end care. It is compatible with color-treated hair; however, always patch-test new products or consult your stylist if you have very porous or chemically treated hair.

• Safe for color-treated hair when used as directed.
• Lightweight enough for fine hair yet nourishing for thick, coarse textures.
• Suitable for chemically treated or heat-styled hair seeking repair support.

Who is this for? Redken Extreme Length Leave-In Treatment is made for anyone with fragile, damaged, or breakage-prone hair who wants to protect existing length and improve hair surface health. If you regularly heat-style, chemically process, or struggle with split ends and snapping strands, this treatment offers daily-strengthening and smoothing benefits as part of a regular care routine. Professional-grade and science-backed, it pairs best with the full Extreme Length system for cumulative results.

Ingredients

AQUA / WATER / EAU</div><div>AMODIMETHICONE</div><div>CETEARYL ALCOHOL</div><div>TRIDECETH-5</div><div>POLYQUATERNIUM-37</div><div>PHENOXYETHANOL</div><div>PROPYLENE GLYCOL DICAPRYLATE/DICAPRATE</div><div>STEARETH-20</div><div>PARFUM / FRAGRANCE</div><div>SODIUM HYDROXIDE</div><div>CITRIC ACID</div><div>GLYCERIN</div><div>PHENYL TRIMETHICONE</div><div>CETYL HYDROXYETHYLCELLULOSE</div><div>TRIDECETH-10</div><div>PPG-1 TRIDECETH-6</div><div>CETYL ALCOHOL</div><div>PRUNUS AMYGDALUS DULCIS OIL / SWEET ALMOND OIL</div><div>BIOTIN</div><div>POLYQUATERNIUM-67</div><div>ARGININE</div><div>BEHENTRIMONIUM METHOSULFATE</div><div>CHLORHEXIDINE DIGLUCONATE</div><div>QUATERNIUM-33</div><div>SORBITAN OLEATE</div><div>ACETIC ACID</div><div>BENZYL BENZOATE</div><div>2-OLEAMIDO-1,3-OCTADECANEDIOL</div><div>HYDROLYZED SOY PROTEIN</div><div>LIMONENE</div><div>BENZYL ALCOHOL</div><div>LINALOOL</div><div>SILICA DIMETHYL SILYLATE</div><div>HYDRATED SILICA</div><div>POLYSORBATE 60</div><div>HYDROLYZED VEGETABLE PROTEIN PG-PROPYL SILANETRIOL</div><div>SODIUM ACETATE</div><div>SODIUM CHLORIDE</div><div>ISOPROPYL ALCOHOL</div><div>POTASSIUM SORBATE</div>