OLAPLEX Nº.4P Blonde Enhancer Toning Shampoo: The Ultimate Brassy Hair Solution

If you’ve ever spent time and money achieving the perfect blonde, only to watch it turn brassy or yellow within a week, you know the struggle is real. Brassiness is one of the most common frustrations for blonde, silver, and gray hair—caused by everything from hard water minerals to UV exposure and heat styling. The solution often comes in a purple bottle, but not all purple shampoos are created equal. Enter the OLAPLEX Nº.4P Blonde Enhancer Toning Shampoo, a toning shampoo that promises to neutralize unwanted warmth while repairing and strengthening your hair from the inside out.

In this product review, we’ll break down how the Nº.4P works, who it’s best for, and how it compares to other toning shampoos on the market. Whether you’re a natural blonde, a bleached platinum enthusiast, or someone with highlighted hair, we’ll help you decide if this is the brassy hair solution you’ve been looking for. Plus, we’ll share tips on pairing it with other OLAPLEX favorites for a complete haircare routine.

What Makes OLAPLEX Nº.4P Blonde Enhancer Toning Shampoo Different?

Most purple shampoos rely on violet pigments to cancel out yellow and orange tones, but they often leave hair feeling dry, brittle, or stripped. The OLAPLEX Nº.4P Blonde Enhancer Toning Shampoo takes a different approach. It combines toning technology with OLAPLEX’s patented Bond Building Chemistry™ to repair broken disulfide bonds while you wash. This means you get both color correction and strengthening in one step—a rare combination in the world of toning shampoos.

The formula is sulfate-free and gentle enough for color-treated hair, making it ideal for maintaining salon-fresh blonde between appointments. It also contains nourishing ingredients that help preserve moisture, so your hair doesn’t feel straw-like after use. For best results, use it once or twice a week in place of your regular shampoo, or as needed when you notice brassiness creeping in.

• Neutralizes brassy, yellow, and orange tones with violet pigments
• Repairs and strengthens hair with Bond Building Chemistry™
• Sulfate-free and safe for color-treated, bleached, or highlighted hair

How to Use OLAPLEX Nº.4P for Best Results

To get the most out of your OLAPLEX Nº.4P Blonde Enhancer Toning Shampoo, start by wetting your hair thoroughly. Apply a generous amount to your palms and work it through your strands, focusing on areas where brassiness is most noticeable—usually the mid-lengths and ends. Leave it on for 3 to 5 minutes to allow the violet pigments to deposit evenly. Rinse thoroughly and follow with a conditioner or mask to lock in moisture.

For an even more intensive toning treatment, you can leave the shampoo on for up to 10 minutes, but be careful not to overdo it, especially if you have very porous or lightened hair. Over-toning can lead to a dull, ashy look. If you want to maintain a cool, icy blonde, pair this shampoo with a purple conditioner or a weekly hydrating mask. Many users find that using it twice a week is enough to keep brassiness at bay without over-toning.

• Apply to wet hair and leave on 3–5 minutes for standard toning
• For stubborn brassiness, leave on up to 10 minutes, but monitor results
• Always follow with a moisturizing conditioner or mask

Who Should Use This Toning Shampoo?

The OLAPLEX Nº.4P Blonde Enhancer Toning Shampoo is designed for anyone with blonde, silver, gray, or highlighted hair who wants to neutralize unwanted warm tones. It’s especially beneficial for those who frequently bleach or color their hair, as the bond-repairing technology helps counteract damage from chemical processing. If you have natural blonde hair that tends to look brassy in summer or after swimming, this shampoo can help maintain a cooler tone.

It’s also a great option for those transitioning to gray hair, as it can tone down yellowing and keep silver strands looking bright and vibrant. However, if you have dark hair or have never colored your hair, this shampoo won’t lighten your hair—it only deposits violet pigments to cancel warmth. For best results, use it as part of a routine that includes other OLAPLEX products, such as the Nº.3 HAIR PERFECTOR™ for weekly bond repair or the Nº.5 BOND MAINTENANCE® CONDITIONER JUMBO for daily moisture.

• Ideal for blonde, silver, gray, and highlighted hair
• Great for chemically processed or bleached hair needing repair
• Not for dark, uncolored hair—it won’t lighten

Comparing Nº.4P to Other Purple Shampoos

What sets OLAPLEX Nº.4P apart from drugstore purple shampoos is its dual-action formula. Many toning shampoos focus solely on color correction and can be harsh, leaving hair dry and tangled. OLAPLEX’s bond-building technology actively repairs hair, making it a standout choice for those who prioritize hair health. While some users may find the price point higher than average, the results often justify the investment, especially for those with damaged or over-processed hair.

Another advantage is the pleasant scent and rich lather, which can be lacking in sulfate-free shampoos. The Nº.4P rinses cleanly without leaving a heavy residue, and it doesn’t stain your hands or shower as much as some other purple shampoos. For a complete toning and strengthening routine, consider pairing it with the Nº.5CURL BOND SHAPER™ HYDRATING CURL CONDITIONER if you have curly or textured hair, or the OLAPLEX º7 SHINE SERUM OIL MIST for added shine and frizz control.

• Bond repair sets it apart from standard purple shampoos
• Sulfate-free, gentle, and non-staining formula
• Pairs well with other OLAPLEX products for a full regimen

Our Verdict: Is OLAPLEX Nº.4P Worth It?

After testing the OLAPLEX Nº.4P Blonde Enhancer Toning Shampoo over several weeks, we can confidently say it’s one of the best toning shampoos on the market for those who want both color correction and hair repair. It effectively reduces brassiness without over-drying, and the bond-building technology leaves hair feeling stronger and healthier over time. While it may not be the cheapest option, the quality and results make it a worthwhile investment for anyone serious about maintaining their blonde.

If you’re on the fence, start with a smaller bottle to see how your hair responds. Most users notice a visible difference after just one or two washes. For an even more comprehensive routine, consider the HYDRATING CURL SHAMPOO & CONDITIONER SET if you have textured hair, or the RICH HYDRATION MASK for deep moisture. The Nº.4P is a versatile addition to any haircare arsenal, especially for those who love the convenience of a shampoo that tones and repairs in one step.

• Effective at neutralizing brassiness with consistent use
• Strengthens hair over time, reducing breakage
• Best for those who value both color and hair health

If you’re tired of battling brassy tones and want a shampoo that actually strengthens your hair while toning, the OLAPLEX Nº.4P Blonde Enhancer Toning Shampoo is a game-changer. Ready to transform your blonde? Explore the full range of OLAPLEX products to create a personalized routine that keeps your hair vibrant, healthy, and brass-free.