Our Rating:
4.9
Olaplex Nº. 4 Bond Shampoo Review
Ranked #2 (Runner-up)
Best Shampoo in 2025!
Authors: Diana F, Karly R, David U, Shaun D
Introduction
Olaplex Nº. 4 Bond Maintenance Shampoo is a game-changer in the world of hair care that has earned our overall rank #2 pick for best shampoo in 2025. While another shampoo may have captured the top spot, for those of us who are truly serious about repairing damage and restoring our hair’s health from the inside out, Nº. 4 is the shampoo for you!
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This shampoo changes the way we should think about cleansing, moving it from a simple necessity to a crucial, active step in the restorative process. After months of using this shampoo, it has become a part of our daily routine that delivers salon-quality science right into your shower. Out of the many shampoos we tested, the fact that it beats out other shampoos and is the runner-up says that it has so much to offer!
Science Behind the Olaplex Nº. 4
Before you can truly appreciate what makes this shampoo so special, you have to understand a little secret about your hair.
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What is Hair: Think of your hair’s structure like a ladder. The sides of the ladder are long keratin proteins, and the rungs holding everything together are tiny, powerful connections called disulfide bonds. These bonds are what give your hair its strength, its shape, and its resilience. When we color our hair, use hot tools, or even just brush it, we break these delicate bonds. The result? Frizz, dullness, split ends, and that dreaded gummy, fragile feeling.
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Science of Olaplex Nº. 4: This is where Olaplex’s genius comes in. The formula contains a patented, one-of-a-kind molecule called Bis-Aminopropyl Diglycol Dimaleate. That’s a mouthful, but what it does is beautifully simple. It’s like a tiny repair drone that travels inside the hair shaft and is designed to repair your hair's internal structure by targeting damaged areas. It’s performing a structural repair from within. This is why the results feel so transformative and lasting—it’s real strength, not just an illusion of health.
First Impressions
The entire experience of using Olaplex Nº. 4 feels elevated and incredibly thoughtful, starting from the very first use.
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Scent and Texture: The shampoo itself is a lesson in luxury. It’s thick and pearlescent, with a concentrated, creamy consistency that feels incredibly rich. You can tell immediately that this is a premium product. The scent is absolutely divine—it’s clean, subtle, and sophisticated, with light, fresh notes of citrus that make your shower feel like a spa. It’s not overpowering or perfumey, just wonderfully pleasant and clean.
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The Lather: One of the most amazing things about Nº. 4 is the lather. Many of us have been trained to think that "sulfate-free" means "lather-free," but Olaplex completely debunks that myth. After working a small, dime-sized amount between my palms, I was shocked at the rich, voluminous, and incredibly satisfying lather it produced. It spreads beautifully, allowing you to get a deep, effective clean without ever feeling like you’re stripping your hair of its natural moisture. It feels both gentle and powerful at the same time.
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A Little Goes a Long Way: This shampoo is unbelievably concentrated. My hands-on experience taught me very quickly that you need far less than you think. A tiny amount is more than enough to wash even long, thick hair, which means that one bottle lasts for a surprisingly long time. It’s a perfect example of quality over quantity, and the concentration makes it feel like an excellent value.
Performance
This is where Olaplex Nº. 4 truly shines and builds its legendary reputation; its performance on hair that is crying out for help is simply astonishing.
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Savior for Color-Treated Hair: If you have ever bleached or colored your hair, you know the damage I’m talking about. After just a few washes with Nº. 4, the difference was night and day. Hair that felt brittle, dry, and prone to snapping started to feel soft, supple, and dramatically stronger. It helps to reduce breakage so significantly that you’ll notice less hair in your brush and on your floor. It breathes life back into over-processed strands, making them look and feel healthier, shinier, and more resilient than you thought possible.
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A Dream for Curly Hair: For those of us blessed with curls, the battle against frizz and dryness is constant. Nº. 4 is a phenomenal ally in that fight. It provides deep, meaningful hydration that helps curls clump together beautifully, enhancing definition and creating a soft, touchable texture. My daily use of this shampoo resulted in significantly less frizz, even in humid weather, and my curls felt bouncy and hydrated without being weighed down.
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For Fine-Haired Girls: The formula is undeniably rich and intensely moisturizing, which is a miracle for most hair types. For those with very fine or easily weighed-down hair, the original Nº. 4 might feel a bit heavy. This is a testament to its powerful conditioning properties! The key is to use an even smaller amount and to really focus the application on your mid-lengths and ends, using only the residual lather at the roots. For those who prioritize pure volume over deep repair, Olaplex has other incredible, lighter formulations designed specifically for you.
Olaplex System
While Olaplex Nº. 4 is a powerhouse on its own, its true potential is unlocked when you embrace it as part of a system.
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Better Together: Olaplex was designed as a multi-step regimen where each product builds upon the last. Using the Nº. 4 shampoo in conjunction with the Nº. 3 Hair Perfector (a pre-shampoo treatment) and the Nº. 5 Bond Maintenance Conditioner creates a hair-repairing synergy that is simply unmatched. The Nº. 3 does the intensive, deep-level bond rebuilding, and the Nº. 4 and Nº. 5 then maintain, support, and continue that repair with every single wash.
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Salon-Level Maintenance at Home: For me, incorporating the full system into my routine transformed my hair care from a simple chore into a true self-care ritual. It’s the closest you can get to that fresh-from-the-salon feeling of strong, healthy, professionally treated hair. The shampoo plays a vital role in this ecosystem, ensuring that you are cleansing gently while continuing to deposit that magic bond-building molecule, reinforcing your hair’s strength day after day.
Conclusion: The Runner Up
To put it simply, Olaplex Nº. 4 Bond Maintenance Shampoo is far more than just a cleanser. It is a restorative treatment in a bottle that delivers on its promise of stronger, healthier hair. The visible reduction in breakage, the return of shine and softness, and the tangible feeling of increased strength are undeniable!
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Although it can't compare to our #1 pick, for anyone searching for a genuine solution in a hair restorative salon-quality treatment, the Olaplex Nº. 4 Bond shampoo is the essential choice! ✨✨✨