NIOXIN Scalp + Hair Thickening System 1 Leave-In Treatment, 6.8 fl oz — Lightweight Volume for Natural or Untreated Hair

Nioxin Scalp + Hair Thickening System 1 Leave-On Treatment is a lightweight, salon-grade leave-in formula designed to nourish the scalp and visibly increase hair fullness for natural or untreated hair with light thinning.

This professional-strength treatment is the finishing step in Nioxin’s three-part System 1, engineered to refresh the scalp, strengthen individual strands, and amplify texture without weighing hair down. Using Transactive Delivery System 2.0 technology, the formula delivers targeted nutrients, antioxidants, and botanicals to the scalp and hair shaft to help protect against breakage and support a healthy scalp environment.

How will this treatment change my hair’s appearance?

The leave-on treatment is formulated to make each hair strand appear thicker so the overall mane looks fuller and more voluminous. Results reported by users include increased density and a noticeable boost in hair body within weeks of consistent use.

• Increases strand diameter for thicker-looking hair
• Boosts overall fullness and texture
• Adds shine without heaviness or build-up

What does it do for scalp health and follicle environment?

Nioxin System 1 focuses on balancing and clarifying the scalp to create a healthy foundation for hair. The formula helps remove excess sebum and impurities that can affect follicle performance while delivering antioxidants and botanicals to nourish the skin at the roots.

• Gently refreshes and clarifies the scalp surface
• Delivers antioxidants to support a healthier scalp condition
• Helps maintain balanced sebum levels that can prevent clogging

How does it integrate into my daily hair routine?

Use the treatment as the final step after cleansing and conditioning with System 1 products for best results. It’s a leave-in product, so apply it directly to the scalp and hair where thinning is visible, then style as usual; no rinsing required.

• Apply to towel-dried or dry hair after System 1 wash and conditioner
• Target scalp zones and massage gently to distribute evenly
• Compatible with typical styling tools and products

What evidence supports its effectiveness?

Clinical feedback and consumer studies have shown that many users observe thicker-looking hair and improved fullness with regular use. Nioxin’s protocols and Transactive Delivery System 2.0 aim to improve strand resilience and reduce the visible signs of light thinning.

• High consumer-reported improvements in thickness and density
• Formulated to protect against breakage and strengthen strands
• Professionally positioned as the concluding step in a targeted three-part system

Who is this for: This leave-on treatment is intended for people with natural or untreated hair experiencing light thinning who want a salon-grade product to enhance hair thickness and scalp condition. It’s appropriate for daily use as part of Nioxin System 1 and for anyone seeking a non-greasy option to boost volume without altering hair color or texture treatments.

Ingredients

WATER/EAU, NIACINAMIDE, CAFFEINE, PHENOXYETHANOL, SODIUM BENZOATE, BENZYL ALCOHOL, ACRYLATES/C10-30 ALKYL ACRYLATE CROSSPOLYMER, POLYSORBATE 60, POLYSORBATE 80, ACETAMIDE MEA, TRIETHANOLAMINE, PROPYLENE GLYCOL, PEG-23M, TETRASODIUM EDTA, METHYL NICOTINATE, FRAGRANCE/PARFUM, PEG-30 DIPOLYHYDROXYSTEARATE, MENTHA PIPERITA (PEPPERMINT) OIL, MENTHA ARVENSIS LEAF OIL, MENTHOL, TRIDECETH-6, CAMELLIA SINENSIS LEAF EXTRACT, LIMONENE, SILICA, CYSTINE BIS-PG-PROPYL SILANETRIOL, BIOTIN, LECITHIN, TOCOPHERYL ACETATE, CITRUS PARADISI (GRAPEFRUIT) PEEL EXTRACT, HUMULUS LUPULUS (HOPS) FLOWER EXTRACT, URTICA DIOICA (NETTLE) LEAF EXTRACT, YEAST EXTRACT/EXTRAIT DE LEVURE, ACER SACCHARUM (SUGAR MAPLE) EXTRACT, CITRUS LIMON (LEMON) PEEL EXTRACT, SACCHARUM OFFICINARUM EXTRACT, VACCINIUM MYRTILLUS LEAF EXTRACT, CITRUS AURANTIUM DULCIS (ORANGE) FRUIT EXTRACT, POTASSIUM SORBATE.