Nioxin Diameter System 4 Scalp & Hair Treatment is the targeted step 3 in the 3D Care System Kit 4, crafted for colored hair with progressed thinning. This color-safe formula works with your routine to strengthen hair resilience while balancing scalp moisture, unveiling thicker, fuller-looking strands.

Shake well before use. Apply evenly to the entire scalp. No rinse required — simply let it work as you go about your day.

• Scalp Access Delivery 2.0 with UV-protection ingredients to shield color-treated hair from sun damage.
• Enhances hair resilience and helps maintain moisture balance for softer, less brittle strands.
• Color-safe formula designed to preserve tone and vibrancy in dyed hair.
• No-rinse, convenient scalp treatment that fits into a quick morning or evening routine.
• Part of the Nioxin 3D Care System Kit 4, Step 3, tailored for progressed thinning.
• Compact 100 ml / 3.38 oz bottle ideal for home use and travel.

Discover the difference today with Nioxin Diameter System 4 and enjoy thicker, fuller-looking hair you can see and feel.