NIOXIN Scalp + Hair Thickening Leave-In Treatment 6.8 fl oz — lightweight, strand-amplifying for natural/light-thinning hair

NIOXIN Scalp + Hair Thickening System 1 Leave-On Treatment is a salon-formulated, leave-in scalp and strand treatment designed to increase the apparent thickness and fullness of natural or untreated hair with light thinning.

This lightweight, leave-on formula is the finishing step of NIOXIN System 1, formulated to refresh the scalp, amplify strand diameter, and help protect hair from breakage. Using Transactive Delivery System 2.0 technology, the treatment delivers botanicals, antioxidants, and nutrients to the scalp and hair to help create a healthier-looking foundation for hair that appears fuller and has enhanced texture and shine.

How does this treatment make hair look thicker?

The treatment works by coating and amplifying individual hair fibers to create the perception of increased diameter and density. It uses targeted delivery technology to distribute active ingredients where they contact the scalp and hair shaft, improving texture without heavy build-up.

• Transactive Delivery System 2.0 for targeted nutrient delivery
• Strand-amplifying ingredients that increase hair fiber diameter
• Lightweight, leave-on formula that avoids greasiness
• Visible improvement in fullness reported within 30 days by users

What results can I expect and how quickly?

Clinical and consumer feedback indicate noticeable changes in thickness, fullness, and hair density with continued use. Results vary by individual, but many users report perceivable improvement in about a month when System 1 products are used as directed.

• 85% of consumers noticed a thickening effect in consumer evaluations
• 80% reported increases in hair density and hair fullness
• Designed as the final, leave-in step to lock in benefits after cleansing and conditioning

How do I use the NIOXIN System 1 leave-on treatment in my routine?

Apply the leave-on treatment after completing the System 1 Shampoo and Conditioner steps for best results. Dispense the recommended amount, massage into the scalp and distribute through hair where thinning is present, and leave it in—no rinsing required.

• Use after cleansing and conditioning with the matching System 1 products
• Massage into the scalp and comb through to the ends as needed
• Leave on; style as usual
• Consistent application supports cumulative visible improvements

Is this safe for my natural or untreated hair?

System 1 is formulated for natural or untreated hair with light thinning and aims to support scalp balance and hair resilience without harsh effects. It contains botanicals and antioxidants intended to nourish the scalp while helping to reduce breakage from mechanical stress.

• Formulated specifically for natural, untreated hair
• Includes antioxidants and botanicals for nourishing the scalp
• Designed to help protect hair from breakage and maintain texture

Who is this for: This 6.8 fl oz NIOXIN Scalp + Hair Thickening System 1 Leave-On Treatment is intended for people with natural or untreated hair experiencing light thinning who want a salon-grade, leave-in step to boost hair texture, protect strands, and support a healthier-looking scalp. It’s best used as the final step in the System 1 regimen when you want a lightweight, non-greasy finishing treatment that enhances fullness and shine without weighing hair down.

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.