Redken Acidic Grow Full System Instant Densifying Shampoo

Your density routine starts here. This gentle, pH-rebalancing shampoo cleanses the scalp while laying the foundation for visibly fuller, thicker hair with every wash. Powered by a 5% Densifying Complex and formulated for fine, flat hair, it removes buildup without stripping — leaving the scalp balanced and hair primed for the fullness it delivers throughout the rest of the system.

✔ Thin, flat, or fine hair
✔ Hair prone to fall and breakage from brushing
✔ All hair types, including color-treated

KEY BENEFITS

• Visibly fuller, thicker-looking hair — the first step in the system designed to unlock the fullness of +5,000 hair fibers*
• 2X stronger strands — clinically tested to build resilience from the very first step
• 2X less breakage — from brushing and everyday styling
• Gentle, scalp-rebalancing cleanse — removes buildup without disrupting the scalp's natural acid mantle
• Clinically tested to hydrate the scalp — cleans and nourishes in one step
• Available in a 1L value size — In both Shampoo and Conditioner formats

*91% of users in a consumer study agreed hair feels thicker.

Acidic Grow Full System Shampoo, Conditioner, Serum & Densifying Spray

The full system. The full result. When all four Acidic Grow Full products work together, they unlock the fullness of +5,000 hair fibers* — cleansing, conditioning, rebalancing, and densifying at every step of your routine. This bundle gives you everything you need to go from flat and thinning hair to achieve visibly fuller, stronger, denser hair. 

Ideal For:

✔ Thin, flat, or fine hair
✔ Hair prone to fall and breakage from brushing
✔ Anyone starting or committing to a full density routine
✔ All hair types, including color-treated

Learn about this collection:

Acidic Grow Full Densifying Shampoo The system starts here. Gently cleanses and rebalances scalp pH while laying the foundation for visibly fuller hair with every wash.

Acidic Grow Full Densifying Conditioner Lightweight hydration that builds body without weight. Conditions strands from mid-length to ends, leaving hair softer, stronger, and primed for density.

Acidic Grow Full Scalp & Hair Serum The targeted treatment step. Sprays directly onto the scalp to energize the root environment, reduce breakage, and build long-term density where it starts.

Acidic Grow Full Instant Densifying Spray The finishing touch. A no-rinse leave-in that delivers immediate visible fullness while protecting hair from heat styling up to 450°F.

KEY BENEFITS:

Visibly fuller, thicker-looking hair — powered by the +5,000 hair fiber Densifying Complex*
2X stronger strands — clinically tested across the full system
2X less breakage — from brushing and everyday styling
Scalp pH rebalancing — Azelaic Acid targets the root cause of thinning at the source
Clinically tested to hydrate the scalp — every step nourishes as it treats

*91% of users in a consumer study agreed hair feels thicker.

HOW TO USE: 

Apply Acidic Grow Full Shampoo to wet hair. Lather and rinse. After shampooing, apply Acidic Grow Full Conditioner from mid-length to ends. Rinse. Spray Acidic Grow Full Scalp & Hair Serum half an inch away from the scalp on clean, damp hair. Massage into scalp. Spray Acidic Grow Full Densifying Spray six inches away from hair, on clean, damp hair. Comb through from mid-sections to ends.