Thin, flat hair has a habit of falling for every volumising promise going, then falling flat again by lunchtime. Redken's Acidic Grow Full System Densifying Shampoo is the litre-sized opening act in a routine built to cleanse the scalp, settle the drama and leave fine hair looking fuller from the very first wash.
TL;DR: A lightweight, vegan densifying shampoo for thin, flat, fine and colour-treated hair. Powered by azelaic acid, caffeine and prebiotics, it gently cleanses without stripping and rebalances the scalp — the foundational first step of Redken's Acidic Grow Full System, now in a generous 1L salon size.
Product Details and Benefits
- Densifying shampoo formulated for thin, flat and fine hair, plus hair prone to fall and breakage from brushing.
- Suitable for all colour-treated hair.
- Azelaic acid rebalances the scalp mantle's natural acidic pH.
- Caffeine energises and helps awaken the scalp.
- Prebiotics moisturise the scalp's acid mantle for a healthier feel.
- Lightweight formula that gently cleanses without stripping the scalp's protective barrier.
- Warm citrus fragrance: Italian lemon up top, neroli through the middle, vanilla bean at the base.
- Vegan (no animal-derived ingredients) and never tested on animals.
- As the first step of the complete Acidic Grow Full System (shampoo, conditioner, serum and spray), it contributes to instantly fuller, thicker-looking hair that is 2X stronger with 2X less breakage*, and hair that 91% of GLP-1 users experiencing hair loss agreed felt thicker.**
- Generous 1L / 33.8 fl oz salon size — built for high rotation and busy bathrooms.
How to Use
- Wet hair thoroughly with warm (not scalding) water.
- Work a small amount into the scalp and massage into a rich lather.
- Rinse well, then repeat if your hair's had a big week of styling, dry shampoo or gym sessions.
- Follow with the rest of the Acidic Grow Full System — Densifying Conditioner, Scalp & Hair Serum and Instant Densifying Spray — for the full effect.
Pro tip: This is a scalp-first formula, so let the lather sit on your scalp for 30 to 60 seconds before rinsing. That gives the azelaic acid, caffeine and prebiotics time to do their work where it actually counts — at the roots, not just the lengths.
Why You'll Love It
If your hair reads more faint whisper than full volume, this is where the conversation changes. Add the litre of Redken Acidic Grow Full System Densifying Shampoo to your cart and give thin, flat hair the fresh start it's been quietly asking for.
*Strength and reduced-breakage results are based on using the complete Acidic Grow Full System of shampoo, conditioner, serum and spray, compared with a non-conditioning shampoo. Source: redken.com.
**Based on a consumer test using the complete Acidic Grow Full System of shampoo, conditioner, serum and spray, among GLP-1 users experiencing hair loss. Source: redken.com.
