Redken Acidic Bonding Curls Leave-In Treatment for Curly & Coily Hair — 3A–4C, Heat Protectant & Bond-Building

Redken Acidic Bonding Curls Leave-In Treatment is a silicone-free, bond-building leave-in that detangles, repairs and defines curly and coily hair while protecting up to 450°F.

This lightweight leave-in from Redken is formulated specifically for curl patterns 3A–4C to restore curl integrity and manageability. Using Curl-Bond Technology — a blend of citric acid, glycine and urea — it targets weakened linkages in the hair to improve strength and pattern definition. The formula is vegan and free from sulfates, silicones and parabens, and it pairs best with the matching Acidic Bonding Curls shampoo and conditioner for system results.

How will this leave-in make my curls easier to manage?

The leave-in focuses on smoothing the surface and easing friction so detangling becomes faster and gentler. In consumer testing, the treatment made hair significantly easier to comb and noticeably smoother after a single use.

• Delivers 12x easier detangling, reducing breakage during combing.
• Smoothes the cuticle for 12x more conditioned feel.
• Contains avocado and camelina oils to add slip and softness.

Can it actually repair damaged curl structure?

Rather than masking damage, the formula is designed to rebuild internal bonds that support curl shape and resilience. Citric acid, glycine and urea work together to fortify compromised areas, improving curl pattern and reducing the appearance of split ends over time.

• Curl-Bond Technology targets internal bond rebuilding for stronger fibers.
• Visible improvement in curl definition and resilience after system use.
• Supports healthier-looking curls without silicones that can weigh hair down.

Is it safe to use before heat styling and color-treated hair?

Yes — the leave-in provides heat protection up to 450°F, so it’s suitable for blow-drying and hot tools when you need to style. The silicone-free, sulfate-free formulation is also safe for color-treated hair when used as directed.

• Shields strands from heat up to 450°F for safer styling.
• Formulated without sulfates, silicones and parabens for gentler care.
• Works with color-treated curls, adding moisture and protection.

How long do the hydration and definition benefits last?

The leave-in delivers multi-day control for many users, with long-lasting hydration and frizz reduction when used as part of the Acidic Bonding Curls system. Results vary by hair porosity and styling routine, but testing showed extended definition and reduced frizz duration.

• Up to 72 hours of defining, hydrating and frizz-fighting benefits.
• Full-bodied curl volume reported for up to 96 hours in consumer tests.
• 85% less frizz observed using the full acidic bonding curls regime versus a non-conditioning shampoo.

Who is this for: This leave-in is made for people with curly or coily textures (3A–4C) seeking a lightweight, silicone-free treatment that improves detangling, rebuilds curl strength and offers robust heat protection. It’s ideal for those who want defined, softer curls without heavy silicones and who plan to use it alongside the matching Redken Acidic Bonding Curls shampoo and conditioner for best results.

How to use: apply to damp hair evenly from mid-lengths to ends, comb through or finger-detangle, then style as desired. Use alone or pair with the Acidic Bonding Curls system for optimal strengthening and definition.

Ingredients

1218393RK4 - INGREDIENTS: AQUA / WATER / EAU • SORBITOL • CETEARYL ALCOHOL • GLYCERIN • BEHENTRIMONIUM CHLORIDE • PERSEA GRATISSIMA OIL / AVOCADO OIL • BIS-DIGLYCERYL POLYACYLADIPATE-2 • TOCOPHERYL ACETATE • CAMELINA SATIVA SEED OIL • PHENOXYETHANOL • HYDROXYETHYL UREA • CETYL ESTERS • PARFUM / FRAGRANCE • ISOPROPYL ALCOHOL • POLYQUATERNIUM-37 • SODIUM CITRATE • POLYQUATERNIUM-4 • PROPYLENE GLYCOL DICAPRYLATE/DICAPRATE • CITRIC ACID • PECTIN • LIMONENE • PPG-1 TRIDECETH-6 • GLYCINE • SUCROSE • LINALOOL • ACRYLATES/STEARYL METHACRYLATE COPOLYMER • SORBITAN OLEATE • CITRONELLOL • CITRAL • EUGENOL • EDTA • TOCOPHEROL • HELIANTHUS ANNUUS SEED OIL / SUNFLOWER SEED OIL • ROSMARINUS OFFICINALIS LEAF EXTRACT / ROSEMARY LEAF EXTRACT (F.I.L. T70033286/1).