Keratin smoothing: how do you choose by what the pack prints?

Keratin smoothing is a salon service: a smoothing product applied section by section, a processing time, then a flat iron that sets the result. To choose the product for your back bar, read the smoothing active printed in its ingredient list: glyoxylic acid, glyoxyloyl derivatives, plant tannins or cysteamine.

Words like “keratin”, “tannin” or “protein” usually describe the service. The formula is what the ingredient list on the bottle shows. This guide sorts seven professional products from our shop by chemical family, with the iron temperature, the processing time and the protocol step exactly as their directions print them.

Keratin smoothingCompositionFor salons

What is keratin smoothing, on the product side?

On the product side, it is a smoothing cream or mask whose effect is set by the heat of the iron. What separates one product from another is the smoothing active and the product's place in the protocol: a product used alone, or Step 2 of a system.

How do you compare professional keratin smoothing products?

Compare them on four printed lines: the smoothing active, the step, the iron temperature and the processing time. The table gives these values as each 1-litre bottle prints them. Two products from the same family can follow different protocols, so read the row for the product you actually use.

Family	Product	Iron and processing time	Size	Source
Glyoxylic acid	Vitta Gold Nanoplex Arginina Hair Smoothing Protein	Iron 180 to 230 °C; 40 to 60 min, depending on hair thickness	1,000 ml	Directions on the bottle
Glyoxyloyl derivatives	Brazilicious Tanino Therapy Step 2 Anti-Frizz Mask Tanino Edition	Iron 180 °C; 40 min (Step 2 only)	1,000 ml	Directions on the bottle
Glyoxyloyl derivatives	omniá Premium Tanino Conditioner Volume Reducer	30 min processing	1,000 ml	Directions on the bottle
Plant tannins	Salvatore Blue Gold Premium Step 2	Iron 180 to 200 °C maximum on blonde hair; 30 min (Step 2 only)	1 L	Directions on the bottle
Plant tannins	Salvatore Blue Gold Condicionador de Realinhamento (2º Passo)	Iron 180 to 200 °C maximum, blonde hair	1 L	Directions on the bottle
Cysteamine	Brazil Protein Nano Gel Hair Straightening Cream	At least 40 min processing	1 L	Directions on the bottle
Cysteamine	Brazil Protein Bio Lamination Straightening Cream	Iron 204 °C on average; 10 to 50 min, depending on hair type	1 L	Directions on the bottle

The processing time for a Step 2 does not include Step 1, so do not set it against a product that is applied on its own.

What should you know about glyoxylic acid smoothing?

Glyoxylic acid smoothing uses this acid as its smoothing active, activated by the heat of the iron. The Vitta Gold Nanoplex Arginina Hair Smoothing Protein prints it second on its list, straight after water.

Its directions ask for a strand test before every application. After washing, dry the hair completely and apply the product 1 cm from the scalp. Then rinse off 60%, blow-dry and iron each section 10 to 15 times at 180 to 230 °C. We point it to salons that adjust processing to hair thickness, since the directions leave a 20-minute window for exactly that.

What should you know about glyoxyloyl smoothing?

A glyoxyloyl derivative carries a group taken from glyoxylic acid, attached to a carrier such as carbocysteine or keratin amino acids. The Brazilicious Tanino Therapy Step 2 Anti-Frizz Mask Tanino Edition prints two of them at the top of its list: GLYOXYLOYL CARBOCYSTEINE and GLYOXYLOYL KERATIN AMINO ACIDS.

It is Step 2 of a system. Start with the Tanino Therapy Step 1 Clarifying Shampoo, dry the hair to 70%, divide it into 4 parts and apply Step 2 at 1 cm from the root.

Our view: keep both bottles side by side at the back bar, because Step 2 is not used on its own.

The omniá Premium Tanino Conditioner Volume Reducer also prints GLYOXYLOYL CARBOCYSTEINE and GLYOXYLOYL KERATIN AMINO ACIDS. Its directions start from hair dried to 80% after the shampoo, applied strand by strand and combed through with a fine comb.

Our tip: set the iron temperature and the number of passes from your strand test.

What should you know about plant-tannin smoothing?

Plant-tannin smoothing relies on tannins and Brazilian plant extracts. The Salvatore Blue Gold Premium Step 2, a 1 L hair realignment conditioner, prints these extracts at the head of its formula and tannin further down the list.

It goes on after Step 1 of the same system, on damp hair. Its directions give 30 minutes' processing, then a thorough rinse. Iron slowly in thin 1 cm sections, an average of 10 passes depending on fibre strength, working the root more than the ends. On blonde hair, its directions advise 180 to 200 °C maximum, depending on fibre strength, to avoid dryness and tonality loss. The Salvatore Blue Gold Condicionador de Realinhamento (2º Passo), in a 1 L navy bottle, goes on completely dry hair instead. Its directions ask for 1 cm sections and at least 10 passes depending on fibre resistance. Its Spanish directions give 180 to 200 °C maximum for blonde hair.

For the method in detail, read our tannin smoothing guide.

What should you know about cysteamine smoothing?

Cysteamine smoothing uses cysteamine hydrochloride, CYSTEAMINE HCL on the list, as its smoothing active. Both Brazil Protein creams in our table present themselves as straightening creams and print it, with CYSTEINE HCL further down the list.

The Brazil Protein Nano Gel Hair Straightening Cream prints it second, straight after water. Its directions start on unwashed hair, applied strand by strand.

Then wet the hair, remove the excess water and dry; the Dutch and Portuguese directions on the bottle then name the flat iron. Our tip: set the iron temperature from your strand test.

The Brazil Protein Bio Lamination Straightening Cream prints cysteamine fourth, after malic acid. Its directions give 10 to 50 minutes depending on hair type, then a rinse, a dry and a flat iron on thin strands at an average of 204 °C. Our view: with both creams, follow the directions on the bottle in your hand, line by line.

What precautions apply during keratin smoothing?

Do a strand test before the service: the Vitta Gold and Brazilicious directions both ask for one.

• Strand test. “Always test on a lock of hair.” (Brazilicious Tanino Therapy Step 2)
• Scalp. “Apply without touching the scalp.” (Brazilicious); “Avoid eyes, skin, scalp, and mucous membranes.” (Vitta Gold)
• Irritated scalp. Do not apply to an irritated scalp. (Brazilicious, directions on the bottle)
• Gloves. Both sets of directions recommend gloves; the Vitta Gold directions also ask for a ventilated area.

We suggest keeping these instructions within reach at the station, as printed.

Frequently asked questions

Updated 8 October 2026.