What you get for $39

The US full-size 8.5 fl oz bottle (SKU K18-40035L) was $39 on November 13, 2026, about $4.59 per fl oz. K18 directs shoppers to swap it in for their regular shampoo weekly or as needed. The label lists added fragrance and a cleansing base of Sodium C14-16 Olefin Sulfonate and Cocamidopropyl Hydroxysultaine.

Manufacturer · US offer and ingredient listK18 PEPTIDE PREP Detox Shampoo

How to read the peptide claim

The ingredient list confirms sh-Oligopeptide-78 is in the shampoo. K18’s published buildup claims describe the finished wash. The listing does not isolate how much the peptide contributes to the result. This review uses the published label and offer and did not test the shampoo.

Manufacturer · US offer and ingredient listK18 PEPTIDE PREP Detox Shampoo

Lower cost per ounce

OUAI Detox Clarifying Hair Shampoo was $34 for 10 fl oz ($3.40 per fl oz). The ingredient list includes vinegar, hydrolyzed keratin and fragrance. Compare the scent and cleansing ingredients if both formulas fit your wash routine.

Manufacturer · US offer and ingredient listOUAI Detox Clarifying Hair Shampoo

A different charcoal formula

Living Proof Clarifying Detox Shampoo was $38 for 8 fl oz ($4.75 per fl oz). It lists charcoal and Tetrasodium Glutamate Diacetate. The brand markets it for product and hard-water buildup. Check the current stock before ordering.

Manufacturer · US offer and ingredient listLiving Proof Clarifying Detox Shampoo, 8 fl oz

Full ingredient list

Water (Aqua) (Eau), Sodium C14-16 Olefin Sulfonate, Cocamidopropyl Hydroxysultaine, Salicylic Acid, Charcoal Powder, sh-Oligopeptide-78, Panthenol, Glycerin, Sodium Phytate, Guar Hydroxypropyltrimonium Chloride, Caprylyl Glycol, Caprylhydroxamic Acid, Citric Acid, Potassium Hydroxide, Sodium Hydroxide, Sodium Chloride, Fragrance (Parfum), Benzyl Salicylate, Limonene, Hydroxycitronellal, Citrus Aurantium Dulcis Flower Oil, Citrus Aurantium Peel Oil, Citrus Limon Peel Oil, Tetramethyl Acetyloctahydronaphthalenes.

Manufacturer · US offer and ingredient listK18 PEPTIDE PREP Detox Shampoo