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

This salon-developed leave-in concentrates nutrients, antioxidants and botanicals at the scalp to protect hair from breakage and support a fuller appearance. Formulated as the final step in Nioxin's System 2 routine, the treatment works alongside the cleanser and conditioner to amplify hair structure, improve manageability and create a healthier surface for hair to grow through.

How does this leave-in help hair that shows progressed thinning?

The treatment targets weakened strands and the scalp environment to reduce breakage and enhance the perception of density. It delivers ingredients like niacinamide and biotin to strengthen hair resilience while antioxidants protect against daily stressors.

• Fortifies hair to resist breakage during styling and brushing
• Delivers scalp-nourishing botanicals that refresh and balance
• Works with System 2 cleanser and conditioner for visible thickening in weeks

What is the correct way to use the Nioxin System 2 Scalp & Hair Treatment?

Apply the leave-in directly to the entire scalp for best results, then gently massage—do not rinse. Use daily as the final step after cleansing and conditioning with the matching Nioxin System 2 products to complete the regimen.

• Apply to dry or towel-dried scalp, sectioning hair as needed for even coverage
• Massage product into the scalp using fingertips to stimulate distribution
• Leave in; style as usual—no rinse required

Which noticeable effects can users expect, and when might they appear?

Many users report improved thickness, density and overall fullness with consistent daily use. While individual results vary, visible improvements in hair body and reduced breakage can appear within weeks when used as part of the System 2 three-step program.

• Perceptible thickening and fuller-looking hair with regular use
• Reduced hair breakage due to strengthened strand structure
• Healthier scalp feel from reduced impurities and balanced sebum

Are there ingredients or benefits I should know about before buying?

The formula blends niacinamide and biotin with antioxidants and botanical extracts to support scalp health and hair resilience. It’s free to be used alongside heat styling and complements salon treatments designed for thinning hair care.

• Includes niacinamide and biotin to support hair strength
• Contains antioxidants and botanicals that protect and nourish
• Designed to integrate with System 2 shampoo and conditioner for full effect

Who this is for: Nioxin System 2 Scalp & Hair Thickening Treatment is aimed at people with natural hair experiencing progressed thinning who want a non-rinse topical that strengthens strands, refreshes the scalp and improves the look of density. It suits daily users who follow a targeted three-step regimen and prefer salon-formulated products focused on scalp care and thicker-looking hair.

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