NIOXIN Diamax Advanced Hair Thickening Serum — 3.38 fl oz | Boosts Strand Diameter & Reduces Breakage

Nioxin Diamax Advanced Hair Thickening Serum is a leave-in treatment that visibly increases individual strand diameter and helps protect hair from breakage for fuller-looking hair.

Designed by a salon brand with over 25 years of focus on thinning hair, this lightweight serum combines HTX technology with caffeine, niacinamide and panthenol to strengthen and energize the scalp and hair shaft. The formula aims to temporarily expand hair fiber thickness while helping reduce damage that can shorten hair length. Use daily as part of your routine to support the appearance of denser, more resilient hair without weighing it down.

How does this serum make hair appear thicker?

The serum works on each strand to increase its visible diameter, creating a fuller overall look. Ingredients in the HTX system swell the hair fiber slightly and add surface lift so gaps between strands look reduced, giving immediate cosmetic thickening for several hours.

• Boosts individual strand diameter for an instant thicker appearance
• Lightweight leave-in texture avoids flattening the hairstyle
• Visible thickening lasts up to around 8 hours with application

Can it help hair grow longer or just look fuller?

While the serum’s primary effect is cosmetic thickening, its strengthening and protective actions support healthier hair over time. By helping reduce breakage at the root and along the shaft, daily use can allow hair to retain length better, which supports longer growth compared with untreated hair.

• Formulated to reduce breakage and protect existing hair
• Nutrients like panthenol and niacinamide support hair resilience
• Consistent use helps hair maintain length by minimizing damage

What scalp and hair types is this suitable for?

Diamax Advanced is formulated to work across a wide range of hair textures and densities. Because it’s a non-greasy, leave-in serum, it can be incorporated into daily styling for fine, medium or coarse hair that needs extra body and breakage defense.

• Suitable for fine to coarse hair types seeking more volume
• Lightweight finish works for daily use without heavy residue
• Useful for scalp care routines that prioritize strengthening and protection

How should I use this treatment for best results?

Apply the serum to clean, towel-dried or dry hair at the roots and along lengths where breakage appears. Massage gently into the scalp and distribute through hair; style as usual. Regular, daily application yields the most consistent visible thickness and protective benefits.

• Apply to scalp and lengths daily for continuous protection
• Work a small amount through towel-dried hair before styling
• Can be layered under styling products without weighing hair down

Who this is for: Nioxin Diamax Advanced Hair Thickening Serum is aimed at people who want immediate visible fullness plus ongoing protection against breakage—ideal for anyone noticing thinning appearance, breakage-prone ends, or lack of body. Salons and daily at-home routines benefit from its blend of fortifying ingredients, making it a practical choice for those seeking a non-greasy, science-backed thickening treatment that complements other Nioxin or styling products.

Ingredients

ALCOHOL DENAT., AQUA/WATER/EAU, NIACINAMIDE, PEG/PPG-20/23 DIMETHICONE, CAFFEINE, ACRYLATES/C10-30 ALKYL ACRYLATE CROSSPOLYMER, PARFUM/FRAGRANCE, GLYCERIN, TETRAHYDROXYPROPYL ETHYLENEDIAMINE, MENTHA PIPERITA (PEPPERMINT) OIL, MENTHA ARVENSIS LEAF OIL, MENTHOL, PEG-30 DIPOLYHYDROXYSTEARATE, BENZYL SALICYLATE, HEXYL CINNAMAL, TRIDECETH-6, ALPHA-ISOMETHYL IONONE, LINALOOL, LIMONENE, CITRONELLOL