This is the complete guide to treatments and smoothing. The shorter guides linked through it go deeper on each question, and the treatments and smoothing page has the salon's prices.
Smoothing, straightening and treatments: 3 different things
A smoothing treatment (keratin, Cezanne, SmoothFiller) coats the outside of the hair, seals the cuticle, and softens wave and frizz for a few months. Your hair still moves and still curls. Nanoplasty works deeper and straightens the hair for longer, still formaldehyde-free and still washing out gradually rather than growing out with a line. A permanent chemical straightener (Japanese straightening, a relaxer) breaks and resets the bonds inside the hair for good, and grows out with a line; the salon works with the first 2 rather than this one. A treatment (Kérastase Fusio-Dose, Premiere, a bond builder, Malibu C) conditions, repairs or resets the hair in a single visit and washes out over 1 to 4 weeks.
How keratin smoothing works
The treatment is applied to clean hair, dried in, and sealed with a flat iron. The keratin and smoothing agents bond to the cuticle, the outer scales of the hair, and hold them flat. Flat cuticles reflect light (shine), let less moisture in (less frizz in humidity), and dry faster and straighter (less blow-dry time). Over 2 to 3 months the coating wears away with washing, and the hair returns to how it was, gradually and without a line.
Cezanne, and why formaldehyde-free matters
Cezanne is a keratin smoothing treatment formulated without formaldehyde or formaldehyde-releasing ingredients, which is what earlier generations of keratin treatments relied on to seal the hair. Being formaldehyde-free, it's comfortable to have applied, it's suitable for colour-treated and lightened hair, and it conditions the hair while it smooths. Cezanne's own site has the product detail; at Jenna Ellen Hair it's the main smoothing treatment on the menu, with SmoothFiller as the lighter option for hair that wants frizz control with less smoothing.
Nanoplasty: when you want it straighter
Nanoplasty is the answer when smoothing is not quite enough: wavy or curly hair that wants a sleek, straight finish, or hair that fights humidity all summer. It's formaldehyde-free, it straightens rather than softens, and it holds for longer than a keratin smoothing before washing out gradually. It's the longest of the 3 appointments and, like the others, it's quoted at a free consultation once your stylist has seen your hair's texture, density and colour history. The treatments page sets the 3 side by side.
Who it suits
Wavy or frizz-prone hair that you'd like to wear smoother with less effort. Blondes whose lightened lengths puff up in humidity. Anyone whose blow-dry lasts a day in summer and would like it to last 3. Fine hair that wants shine and manageability without weight, on a lighter application. And anyone who colours, because the consultation plans the order (colour first, then smoothing) so both hold.
How long it lasts
Up to 3 months, fading gradually. Sulphate-free shampoo, fewer washes, moderate heat and rinsing before the sea or the pool get most clients to the full 3 months. The how long keratin lasts guide has the week-by-week and the aftercare.
What it costs in NZ
Salon smoothing across Auckland is priced by hair length and density, because the amount of product and the time under the iron scale with both. At Jenna Ellen Hair both Cezanne and SmoothFiller are quoted at the free 15-minute consultation so the number is exact for your hair. The appointment itself runs 2 to 3 hours.
The Kérastase in-salon treatments
Fusio-Dose, $50. A concentrate for your hair's main need and a booster for its second, mixed fresh and applied for 5 minutes at the basin. The result is immediate and it's the easiest upgrade to any colour or cut. The Fusio-Dose guide explains the combinations.
Premiere, $70. The deeper repair for hair weakened by colour, heat and water minerals. It lifts the calcium that builds up in damaged hair and rebuilds the fibre, and it's the treatment we recommend between the stages of a dark-to-blonde plan.
Malibu C, $40. A crystal gel that removes mineral and chlorine build-up. Essential on tank or bore water, for swimmers, and for any blonde whose toner keeps drifting warm.
Keratin or bond repair?
They answer different questions. Keratin smoothing works on the outside of the hair for smoothness and frizz control. Bond repair (Kérastase Premiere in the salon; Olaplex-style bond builders at home) works inside the hair, reconnecting the bonds that lightening breaks, for strength. A blonde with frizz uses both: bond repair during and after lightening, smoothing for the finish. The bond repair guide goes into it.
Booking
Smoothing starts with the free consultation, where your hair's length, density and colour history set the price and the order. Fusio-Dose, Premiere and Malibu C are added to any appointment when you book. The treatments and smoothing page has the menu.