Felps Professional Inner Regener Acidifier – pH Sealing, Frizz Control & Post-Chemical Shine – 4.06 fl oz (120 ml)
- Helps rebalance the hair's pH after colouring, bleaching, relaxing or smoothing.
- Helps seal a raised cuticle so the fibre feels smooth and disciplined.
- Helps reduce the appearance of frizz and makes combing easier.
- Helps the mask or conditioner that follows deposit more evenly along the lengths.
Made for chemically processed hair — coloured, bleached, relaxed or smoothed — in any texture, and for stylists who want a proper acid-sealing step at the shampoo bowl. Virgin, untouched hair rarely needs it. Because the pH is very low, it is applied to the lengths with gloves and kept away from the scalp.
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- Formulated and produced in Brazil by Felps Professional, a salon brand based in Cascavel, Paraná.
- Works at a genuinely acidic pH of 2.2 to 2.8, built around Phytoqueratina and Nutrimel Yacon honey.
- Carries a full amino acid blend alongside hydrolyzed keratin and wheat, soy and corn proteins.
- A 120 ml professional bottle — the same acidifier that ships inside the Brazilian Inner Regener kits.
A professional, post-chemical step. After shampooing, apply it to the lengths and ends with gloved hands, keeping it away from the scalp. Leave it on for 3 to 5 minutes without extending the time, rinse with cool or lukewarm water, then follow with a mask and style as usual.
- Fluid, cream-like texture in a 120 ml (4.06 fl oz) bottle sized for salon use.
- This is a low-pH technical product rather than a leave-on — gloves are recommended and it is always rinsed out.
Chemical services leave hair alkaline and swollen, with the cuticle scales standing open. Lactic acid pulls the pH back down to 2.2 to 2.8, which is what prompts those scales to lie flat again. While that is happening, hydrolyzed keratin, wheat, soy and corn proteins plus a full amino acid blend settle into the porous gaps, and the humectants glycerin, sodium PCA and Nutrimel yacon honey hold water in place. Shea butter, coconut oil and the silicone conditioners then smooth the outside, so the fibre finishes acidic, filled and sealed instead of rough and swollen.
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Learn moreEvery chemical service leaves the hair fibre swollen and alkaline. Felps Professional Inner Regener Acidifier – 4.06 fl oz (120 ml) is the salon step that closes the process properly, bringing the hair back to the acidity it prefers.
Formulated at a pH of 2.2 to 2.8 around Phytoqueratina (hydrolyzed keratin and wheat protein) and Nutrimel, a honey drawn from the Andean Yacon potato, it helps seal a raised cuticle and rebalance the fibre from the inside out — exactly what over-processed hair asks for after colouring or bleaching.
The result is lengths that feel disciplined rather than rubbery: frizz drops away, combing gets easier, and the hydration and nutrition of whatever you apply next stay put for longer. Brazilian stylists use it as the bridge between the shampoo bowl and the mask.
Key Features:
- pH 2.2 to 2.8: a genuinely acidic formula that helps close the cuticle after chemical services.
- Post-Chemical Step: built for use after colouring, bleaching, relaxing or smoothing.
- Phytoqueratina: hydrolyzed keratin and wheat protein help fragile strands feel stronger and less porous.
- Nutrimel Yacon Honey: a Brazilian botanical humectant that helps attract and hold moisture.
- Helps Reduce the Appearance of Frizz: a smoother, more aligned surface with fewer visible flyaways.
- Better Combability: behentrimonium and cetrimonium conditioners add slip to fragile, over-elastic hair.
- Makes the Next Step Work Harder: helps your mask or conditioner deposit more evenly along the lengths.
How To Use
Professional Use Recommended.
- Cleanse: wash the hair with your usual Felps Professional shampoo and squeeze out the excess water.
- Apply: with gloved hands, work the acidifier through the lengths and ends, keeping it off the scalp.
- Leave On: let it act for 3 to 5 minutes. Do not extend the time — this is a low-pH formula.
- Rinse: rinse thoroughly with cool or lukewarm water.
- Follow Up: finish with a Felps Professional treatment mask, then style as usual.
Expert Tip: pair it with the Felps Professional S.O.S. Reconstruction Treatment Mask — the low pH helps the mask settle more evenly, so reconstruction and sealing reinforce each other.
Ingredients (Highlights)
- Lactic Acid: the acidifying agent that brings the hair back to a low, cuticle-friendly pH.
- Hydrolyzed Keratin: a protein fragment that deposits along the strand and helps weakened hair feel more resilient.
- Polymnia Sonchifolia Root Juice (Yacon Honey / Nutrimel): a Brazilian botanical humectant that helps hold moisture.
- Butyrospermum Parkii (Shea) Butter & Cocos Nucifera (Coconut) Oil: rich lipids that help soften rough-feeling ends.
- Hydrolyzed Wheat Protein & Carbocysteine: work along the fibre to help improve softness and the appearance of body.
- Amino Acid Blend: arginine, glycine, serine, proline and more, mirroring the building blocks of hair.
- Tocopheryl Acetate (Vitamin E): a conditioning ingredient widely used in hair care formulas.
Full Ingredient List (INCI): Aqua; Cetearyl Alcohol; Lactic Acid; Glycerin; Stearamidopropyl Dimethylamine; Behentrimonium Chloride; Cetyl Alcohol; Cetrimonium Chloride; Cyclopentasiloxane; Bis-Cetearyl Amodimethicone; Butyrospermum Parkii Butter; Cocos Nucifera Oil; Isopropyl Palmitate; Hydroxypropyl Starch Phosphate; Parfum; Hydrolyzed Keratin; Dimethicone; Isopropyl Alcohol; Amodimethicone; Guar Hydroxypropyltrimonium Chloride; Alcohol; Dimethyl Palmitamine; Polyquaternium-7; Disodium EDTA; Hydrolyzed Wheat Protein; Laurdimonium Hydroxypropyl Hydrolyzed Keratin; Sodium PCA; Sodium Lactate; Hydrolyzed Soy Protein; Tocopheryl Acetate; Arginine; Methicone; Trideceth-12; Polymnia Sonchifolia Root Juice; Hydrolyzed Corn Protein; Hexyl Cinnamal; Aspartic Acid; PCA; Phenoxyethanol; Benzyl Salicylate; D-Limonene; Carbocysteine; Polyquaternium-10; alpha-Isomethyl Ionone; Citronellol; Sodium Benzoate; Glycine; Alanine; Benzyl Alcohol; Serine; Potassium Sorbate; Valine; Isoleucine; Proline; Threonine; Magnesium Nitrate; Benzyl Benzoate; Methylchloroisothiazolinone and Methylisothiazolinone; Magnesium Chloride; Histidine; Isoeugenol; Phenylalanine; Citric Acid; Dehydroacetic Acid; Xanthan Gum; Citral; Linalool.
Allergen warnings / usage cautions: This is a low-pH professional formula — wear gloves, keep it off the scalp and rinse thoroughly. It is fragranced and declares the fragrance allergens Hexyl Cinnamal, Benzyl Salicylate, D-Limonene, alpha-Isomethyl Ionone, Citronellol, Benzyl Benzoate, Isoeugenol, Citral and Linalool, and it is preserved with Methylchloroisothiazolinone and Methylisothiazolinone. It contains hydrolyzed wheat, soy and corn proteins — avoid if you are sensitive to any of these. For external use only. Avoid contact with the eyes and rinse immediately with plenty of water if contact occurs. Do not apply to an irritated or broken scalp. Keep out of the reach of children.
Welcome to the world of Felps Professional, where Brazilian salon expertise is bottled for hair that has been through chemistry. Headquartered in Cascavel, Paraná, Felps Professional is a Brazilian professional hair cosmetics brand known for its smoothing and volume-reduction treatments and for home-care lines sold through salons across Brazil and exported to stylists worldwide. Inner Regener is the brand's regeneration protocol, and this acidifier is the step that locks the work in.
FAQ
When exactly do I use it?
After shampooing and before your mask or conditioner. Apply it to the lengths and ends with gloves, leave it on for 3 to 5 minutes, rinse, then continue with your treatment step.
Is this an authentic Felps Professional product?
Yes. It is genuine Felps Professional, sourced in Brazil where the brand is manufactured. The packaging and label text may be printed in Portuguese.
Do you ship internationally, and what if I change my mind?
We ship worldwide with tracking. Delivery times vary by destination, and our standard return and exchange policy applies to unopened items — see our store policy pages for full details.
Which hair types is it suitable for?
It is aimed at chemically processed hair — coloured, bleached, relaxed or smoothed — in any texture. Virgin hair rarely needs it, and because the pH is very low it is best kept off the scalp and used as directed.
Do I still need a mask if I use the acidifier?
Yes, they do different jobs. The acidifier works on the pH and the cuticle; the mask works on nourishment and mass. Used in sequence they complement each other.
Explore more at our Felps Professional collection.