Redken Acidic Bonding Concentrate vs Olaplex No.4 Shampoo

Redken's Acidic Bonding Concentrate line and Olaplex are both sold as "bond" care for damaged hair, so the two are often compared. This comparison looks at each brand's everyday shampoo: Redken Acidic Bonding Concentrate Shampoo and Olaplex No.4 Bond Maintenance Shampoo.

At a glance

Redken Acidic Bonding Concentrate Shampoo

Ulta's page describes it as a sulfate-free shampoo "for all types of damaged hair looking to strengthen hair, reinforce weakened bonds, and lessen breakage". It names citric acid as the key ingredient, which it says "helps reinforce weakened bonds". It also describes an acidic, pH-balancing formula meant to bring hair "back into a healthy range of 4.5-5.5". Redken's results claims (for example "2x less breakage") apply when the shampoo is used as a system with the matching conditioner, and in some claims the leave-in too. The page includes a sunburn alert because the product contains an AHA.

Olaplex No.4 Bond Maintenance Strengthening Shampoo

Olaplex says No.4 "strengthens and reinforces bonds for more resilient hair", and describes it as vegan, color-safe and suitable for chemically treated hair. It says the formula is free of sulfates (SLS/SLES), phthalates, MIC/MIT and parabens. The ingredient list includes Olaplex's bond-building ingredient bis-aminopropyl diglycol dimaleate, along with biotin, sodium hyaluronate, panthenol and several plant oils (sunflower, apricot kernel, argan). The list does include sodium sulfate, which is a salt and not a sulfate cleanser like SLS or SLES. Olaplex says one 250 ml bottle gives up to 100 applications.

Key differences

• How each claims to work on bonds. Redken credits an acidic, citric-acid-based system. Olaplex's formula contains its own bond-building ingredient (bis-aminopropyl diglycol dimaleate).
• Ingredient list length. Redken's list is short (about 27 ingredients). Olaplex's is long, with many botanical extracts and oils, plus colorants (Yellow 5, Yellow 6).
• System claims. Both brands' headline results are for using the shampoo with its matching conditioner.

Verdict: which should you choose?

Choose Redken Acidic Bonding Concentrate if you want a short, sulfate-free, acidic formula and plan to use the matching conditioner and leave-in. Choose Olaplex No.4 if you specifically want a shampoo containing Olaplex's bond-building ingredient, or a brand-stated vegan formula. Already deciding between the brands overall? See Olaplex vs Redken.

Ingredient lists

Redken Acidic Bonding Concentrate Shampoo

Ingredient list as published by Ulta Beauty product page (checked 2026-10-26). Formulas change; always check the pack you buy.

Aqua/Water/Eau, Decyl Glucoside, Sodium Cocoyl Isethionate, Cocamidopropyl Betaine, Citric Acid, Sodium Hydroxide, Panthenol, Glycerin, Dimethicone, PEG-150 Distearate, Ppg-5-Ceteth-20, Sodium Benzoate, Sodium Chloride, Peg-55 Propylene Glycol Oleate, Propylene Glycol, Carbomer, Parfum/Fragrance, Coco-Caprylate/Caprate, Polyquaternium-67, Salicylic Acid, Amodimethicone, Sodium Phytate, Glycol Distearate, Coco-Betaine, Acrylates/Beheneth-25 Methacrylate Copolymer, Limonene, Trideceth-6

Olaplex No.4 Bond Maintenance Strengthening Shampoo

Ingredient list as published by Olaplex (olaplex.com) (checked 2026-10-26). Formulas change; always check the pack you buy.

Aqua (Water, Eau), Sodium Lauroyl Methyl Isethionate, Cocamidopropyl Hydroxysultaine, Potassium Cocoyl Glycinate, Disodium Cocoyl Glutamate, Potassium Cocoate, Sodium Lauroyl Sarcosinate, Sodium Methyl Isethionate, Glycereth-26, Decyl Glucoside, Bis-Aminopropyl Diglycol Dimaleate, Biotin, Sodium Hyaluronate, Panthenol, Tocopherol, Euterpe Oleracea Fruit Extract, Musa Sapientum (Banana) Fruit Extract, Arctium Lappa Root Extract, Punica Granatum Bark/Fruit Extract, Rosmarinus Officinalis (Rosemary) Leaf Extract, Camellia Sinensis Leaf Extract, Morinda Citrifolia Fruit Extract, Origanum Vulgare Leaf Extract, Helianthus Annuus (Sunflower) Seed Oil, Prunus Armeniaca (Apricot) Kernel Oil, Argania Spinosa Kernel Oil, Helianthus Annuus (Sunflower) Seed Extract, Hydrolyzed Vegetable Protein PG-Propyl Silanetriol, Palmitoyl Myristyl Serinate, Polyquaternium-10, Polyquaternium-11, Guar Hydroxypropyltrimonium Chloride, Caprylyl Glycol, Amodimethicone, Divinyldimethicone/Dimethicone Copolymer, Sodium Cocoyl Glutamate, Glycol Distearate, Methyl Gluceth-20, Acrylates Copolymer, PEG-120 Methyl Glucose Dioleate, Cocamidopropylamine Oxide, Disodium Laureth Sulfosuccinate, Ethylhexylglycerin, Sodium Lauryl Sulfoacetate, C11-15 Alketh-7, Laureth-9, Trideceth-12, Glycerin, Laureth-10, C12-13 Alketh-23, C12-13 Alketh-3, Quaternium-95, Propanediol, PEG-8, PEG-8/SMDI Copolymer, Lauric Acid, Sodium Laurate, Sodium Polyacrylate, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, Trisodium Ethylenediamine Disuccinate, Sodium Sulfate, Acetic Acid, Benzoic Acid, Sodium Benzoate, Citric Acid, Potassium Sorbate, Sodium Hydroxide, Phenoxyethanol, Chlorphenesin, Sodium Chloride, Parfum (Fragrance), Citral, Citrus Aurantium Peel Oil, Hexyl Cinnamal, Limonene, Menthol, CI 19140 (Yellow 5), CI 15985 (Yellow 6)

Sources

• Redken Acidic Bonding Concentrate Shampoo: Ulta Beauty product page, checked 2026-10-26
• Olaplex No.4 Bond Maintenance Strengthening Shampoo: Olaplex (olaplex.com), checked 2026-10-26

How we wrote this: we have not tested these products. This comparison only uses what the brands and retailers publish (product descriptions, directions and ingredient lists) on the pages linked under Sources. Claims in quotes are the brand's own. Prices and formulas change, so check the current product page. This is general information, not medical advice.