People growing out their hair whose lengths and ends break, split or feel fragile, including colour-treated and lightened hair, which Redken lists as suitable for the Extreme Length system.

It is a retail, at-home wash-and-condition routine. The holiday box makes it a ready-to-give gift for someone working on longer hair.

Long hair usually stops getting longer because the ends break as fast as the roots grow. Extreme Length is Redken's routine for that specific problem: a biotin shampoo that cleanses without roughing up fragile lengths, followed by a biotin and castor oil conditioner that nourishes and strengthens the ends. Getting both in one holiday box keeps the routine consistent, and adding the Extreme Length Leave-In afterwards completes the system Redken tested for its 81% less breakage result.

• Shampoo: apply to wet hair, massage into a lather and rinse thoroughly.
• Conditioner: after shampooing, apply to damp hair, distribute through lengths and ends, then rinse thoroughly.
• For the full system, Redken recommends following with Extreme Length Leave-In Treatment (sold separately).
• In case of contact with eyes, rinse immediately.

Pros:

• Two full-size 300 ml bottles of the core Extreme Length routine in one gift box
• Biotin in both steps, plus castor oil in the conditioner, aimed at fragile strands and ends
• Suitable for colour-treated and lightened hair, per Redken

Cons:

• Redken's 81% less breakage figure needs the Extreme Length Leave-In Treatment too, which is not in this box
• Helps keep length by reducing breakage; it is not a hair-growth treatment and does not change the natural growth rate
• Limited-edition holiday packaging, available while seasonal stock lasts