NIOXIN System 2 Leave-In Scalp & Hair Thickening Treatment, 6.7 fl oz — Niacinamide & Biotin for Thinning Natural Hair

Designed as the final step in Nioxin's three-part System 2 regimen, this leave-in treatment supports a refreshed scalp environment and improved hair structure without rinsing. The lightweight formula combines niacinamide, biotin, antioxidants and botanicals to target the scalp and hair shaft, helping reduce breakage and promote the appearance of fuller, denser hair when used consistently with the matching Cleanser and Scalp Therapy Conditioner.

How does this treatment support fragile, thinning natural hair?

The formula focuses on strengthening hair from the scalp to the strand by delivering nutrients and protective agents where they matter most. It aims to reduce breakage that contributes to visible thinning and to create a healthier surface for hair to appear fuller.

• Niacinamide and biotin help fortify the hair fiber and support scalp function.
• Antioxidants and botanicals soothe and nourish the scalp, reducing buildup.
• Lightweight, non-greasy leave-in texture leaves hair manageable and primed for styling.

What results can I expect and when might I see them?

Clinical feedback and consumer studies on the Nioxin System report visible changes in hair thickness and density with routine use. Individual timelines vary, but many users notice improved fullness and reduced breakage within weeks of following the full System 2 routine.

• Visible thickening and increased hair fullness reported by many users in about 30 days.
• Reductions in breakage with consistent daily application to the scalp.
• Scalp clarity and healthier-looking hair as the system removes excess sebum and debris.

How do I use this leave-in treatment for best effect?

Apply directly to a clean scalp as the final step in the System 2 three-part program. Gentle massage distributes the formula; do not rinse—style as usual. Daily use is recommended for ongoing scalp nourishment and hair resilience.

• Use after Nioxin System 2 Cleanser Shampoo and Scalp Therapy Conditioner for complete results.
• Apply evenly across the entire scalp, then massage in; no rinsing required.
• Use every day to maintain a refreshed scalp environment and help minimize breakage.

Can this treatment be combined with styling products and color services?

Yes. The treatment is formulated to sit comfortably beneath styling products and can be used alongside regular salon color or chemical services, though professional advice is recommended for complex treatments. Its non-heavy finish helps preserve style while delivering scalp-targeted benefits.

• Compatible with daily styling products; won’t weigh hair down when used sparingly.
• Works with salon color, but consult your stylist for personalized timing and sequencing.
• Protective antioxidants and UV-protecting ingredients help guard hair during exposure.

Who is this for: Nioxin System 2 Scalp & Hair Thickening Leave-In Treatment is intended for people with natural hair experiencing progressed thinning who want a salon-backed, daily leave-in that targets scalp health and reduces breakage. It’s best for those following Nioxin’s System 2 regimen and anyone seeking a lightweight, professional-strength product to enhance hair density appearance and support stronger strands.

Ingredients

Water/Aqua, Phenylbenzimidazole Sulfonic Acid, Niacinamide, Benzophenone-4, Caffeine, Polysorbate 20, Sodium Hydroxide, Benzyl Alcohol, Sodium Benzoate, Phenoxyethanol, Peg-12 Dimethicone, Citric Acid, Cocamidopropyl Betaine, Acetamide Mea, Isopropyl C12-15-Pareth-9 Carboxylate, Propylene Glycol, Tetrasodium Edta, Methyl Nicotinate, Sodium Chloride, Parfum, Polysorbate 60, Polysorbate80, Mentha Piperita Oil, Menthol, Mentha Arvensis Leaf Oil, Peg-23m, Camellia Sinensis Leaf Extract, Limonene, Cystine Bis-Pg-Propyl Silanetriol, Biotin, Lecithin, Tocopheryl Acetate, Citrus Paradisi, Peel Extract, Humulus Lupulus Flower Extract, Urtica Dioica Leaf Extract, Silica, Faex extract, Acer Saccharum Extract, Citrus Limon Peel Extract, Saccharum Officinarum Extract, Vaccinum Myrtillus Leaf Extract, Citrus Aurantium Dulcis Fruit Extract, Potassium Sorbate