Redken Densifying Shampoo for Thinning Hair — Acidic Grow 10.1 fl oz, Lightweight with Azelaic Acid

Redken Acidic Grow Full System Densifying Shampoo is a lightweight, 10.1 fl oz cleansing formula with a 7% Densifying Complex and azelaic acid designed to gently cleanse and help hair look fuller and thicker.

This shampoo is formulated for thin, thinning, or flat hair and created to work as part of the Acidic Grow Full System. It aims to cleanse without stripping the scalp barrier while delivering scalp-balancing ingredients, and it has been evaluated in consumer testing that included GLP-1 users. Use it alongside the matching conditioner, scalp & hair serum, and instant densifying spray for system results.

How does this shampoo support fuller-looking hair?

The formula combines a 7% Densifying Complex with azelaic acid to help create hair that appears thicker and more voluminous when used as part of the full Acidic Grow system. The lightweight texture avoids weighing down fine strands, so lift and body are more noticeable after styling. Results in testing were measured when the complete system—shampoo, conditioner, serum and spray—was used together.

• 7% Densifying Complex to target density and body
• Lightweight surfactants that cleanse without heavy residue
• Azelaic acid for scalp-suitable rebalancing support
• Designed to integrate with conditioner, serum, and spray

Will this shampoo be gentle on my scalp and color-treated hair?

The Acidic Grow shampoo is formulated to cleanse gently and preserve the scalp’s protective barrier, making it suitable for frequent use. It is labeled safe for color-treated hair, so you can expect minimal color fade from normal washing when combined with color-safe routines. The acidic pH helps maintain scalp balance without harsh stripping.

• Formulated to protect the scalp barrier while cleansing
• Safe for color-treated hair with routine use
• pH-balanced, lightweight texture to avoid dryness
• Non-heavy formula ideal for fine or flat hair

How should I use this shampoo for best results?

Apply to wet hair, lather gently at the scalp, and rinse thoroughly; repeat if desired. For optimal performance, follow with the Acidic Grow Full System—conditioner, Scalp & Hair Serum, and Instant Densifying Spray—as the tested regimen delivered the consumer results reported. Regular use helps maintain cleansing, scalp comfort, and the fuller appearance created by the system.

• Use on wet hair, massage into scalp, rinse fully
• Combine with Acidic Grow conditioner, serum, and spray
• Suitable for daily or routine cleansing as needed
• 10.1 fl oz bottle for multiple weeks of regular use

What evidence supports its performance for people experiencing thinning?

Consumer testing included GLP-1 users and showed that participants using the full four-step Acidic Grow system reported thicker-feeling hair. The testing context used the complete system—shampoo, conditioner, serum and spray—so the product is positioned to perform best in combination with the other steps. Individual results vary by hair type and usage habits.

• Tested in a consumer study that included GLP-1 users
• Reported thicker-feeling hair when the full system was used
• Systemic approach: shampoo plus conditioner, serum, spray
• Performance depends on consistent use and hair condition

Who is this for: Redken Acidic Grow Full System Densifying Shampoo is aimed at people with fine, thin, or flattening hair who want a lightweight cleanser that supports a fuller look and a balanced scalp. It’s a fit for those who prefer a system-oriented approach to hair density and for color-treated hair needing gentle cleansing. If you’re seeking lift without added weight and plan to use a coordinating conditioner, serum, and spray, this 10.1 fl oz shampoo is formulated to fit into that routine.

Ingredients

AQUA / WATER / EAU, SODIUM LAURETH SULFATE, COCAMIDOPROPYL BETAINE, SODIUM CHLORIDE, PROPYLENE GLYCOL, PARFUM / FRAGRANCE, CITRIC ACID, COCAMIDE MEA, SODIUM BENZOATE, SODIUM HYDROXIDE, HEXYLENE GLYCOL, BIFIDA FERMENT LYSATE, SACCHAROMYCES/RICE FERMENT FILTRATE, SODIUM LAURYL SULFATE, HYDROXYPROPYL GUAR HYDROXYPROPYLTRIMONIUM CHLORIDE, CAFFEINE, AZELAIC ACID, LINALYL ACETATE, CARVONE, PENTYLENE GLYCOL, LINALOOL, LIMONENE, CITRUS LIMON PEEL OIL, CITRUS AURANTIUM BERGAMIA PEEL OIL, CITRAL, CITRUS AURANTIUM PEEL OIL, PINENE, PHENOXYETHANOL, SALICYLIC ACID