Deep cleans buildup to refresh volume and shine without fading color.
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Looking for a weekly reset that revives volume and shine without wrecking your color? We put Olaplex No.4C to work on different hair types to see how it clarifies, what it takes away, and what it leaves beautifully intact.
Overview
Olaplex No.4C Bond Maintenance Clarifying Shampoo is the brand’s deep-cleansing wash designed to remove what regular shampoos leave behind. Think dulling minerals from hard water, dry shampoo residue, styling product film, excess oils, and pollution. The pitch is simple but ambitious: a true clarifier that still plays nice with color and leaves hair feeling clean rather than stripped.
The formula is sulfate free and pH balanced, which helps keep the cuticle from blowing open. It uses a strong but modern surfactant blend plus chelating and sequestering ingredients to lift mineral deposits and grime, and it includes Olaplex’s bond-building technology to support the hair’s internal structure during the wash. The texture is a clear, medium-thick gel that explodes into a fine, dense lather, and the scent is the familiar clean, lightly sweet Olaplex aroma. The standard bottle is 8.5 ounces with a flip-top cap that is easy to control in the shower.
In use, No.4C functions as a weekly or every-other-week reset shampoo rather than a daily cleanser. It is a high-performance clean with a more cushioned afterfeel than old-school clarifiers. If you live with hard water, use lots of leave-ins, or rotate dry shampoo and stylers through the week, it is the kind of wash that restores brightness and bounce in a single round.
Who it’s for
No.4C is a great fit if any of these ring true:
- Your color looks dull or darker than usual because of product or mineral buildup. This is especially common with highlighted blondes and brunettes who use dry shampoo.
- Your fine or normal hair falls flat by day two and you need a root-reset that actually lasts.
- Your scalp feels grimy or itchy from styling layers and you want a thorough but not punishing cleanse.
- You live in a hard water area or swim occasionally and want to keep tone bright between salon visits.
- You wear curls or coils and cycle creams, gels, and oils that can build up over time.
Adjust or skip if:
- Your hair is very dry, highly porous, or fragile from heavy lightening. You can still use No.4C, but keep it to every 2 to 4 weeks and follow with a rich mask.
- You just colored your hair with a direct dye or vivid semi-permanent. Clarifying can nudge fresh pigments, so wait at least a week.
- You have a keratin or smoothing treatment. Frequent clarifying can shorten its life. Ask your stylist and limit to occasional use when needed.
How it feels and performs
In the hand, No.4C is a clear gel that is easy to spread. It lathers quickly, even on second-day hair, with a silky foam that moves through the roots without feeling rough. The scent is clean and a little sweet but not heavy, and it rinses away without lingering strongly.
During rinsing, hair feels very clean. Slip is lower than a hydrating shampoo, which is normal for a clarifier, so expect the lengths to feel a bit grippy when wet. Once you condition, that grip eases. On dry-down, the finish is airy and lightweight with more lift at the root. Hair brushes easily once conditioned and dried, and the scalp feels genuinely reset.
On color-treated hair: After a week of dry shampoo and hard water showers, No.4C lifts the film that makes color look muted. Highlights look brighter and brunette tones reflect more light. We did not see the sudden dullness or rough ends that older clarifiers can cause when used as directed. If your color is very fresh or you wear fashion shades that sit on the cuticle, be conservative with timing and contact time. Clarifying by nature can remove surface deposits, and semi-permanent pigments behave like deposits.
On oily scalps and fine hair: This is where No.4C shines. Roots feel clean for longer, which helps extend your style. The foam has enough power to slice through sunscreen, scalp oil, and styling layers in one wash. Many testers still preferred two quick lathers on heavy buildup weeks.
On curls and coils: Expect a light, buoyant curl pattern after conditioning. Because the wash removes waxes and oils that can weigh curls down, the ringlets bounce back. The caveat is moisture. You will want a richer conditioner or mask afterward to restore slip and softness, especially if you are high porosity.
On hard water buildup: No.4C includes chelating and sequestering helpers that make a visible difference in tone and feel, especially for blondes who pick up a dingy cast. Severe cases of copper, iron, or swimmer’s green may still need a dedicated chelating session, but for weekly maintenance, No.4C is effective and more comfortable to use.
How to use for best results
- Saturate thoroughly. Warm water helps lift oils and opens the door for the shampoo to work.
- Start at the scalp. Work a quarter-size amount through roots first, then run the lather through mids and ends. Add water to boost foam before adding more product.
- Give it a moment. For heavy buildup or hard water, massage for 30 to 60 seconds so the chelating helpers can work.
- Rinse very well. If you use lots of dry shampoo or stylers, do a second quick lather focused on the scalp.
- Condition immediately. Follow with a hydrating conditioner or mask. Comb through with a wide-tooth comb to restore slip.
- Finish cool if you color. A cool final rinse helps flatten the cuticle and preserve shine.
- Style as usual. Expect lighter, cleaner roots and better volume or curl definition.
Frequency guide:
- Oily or fine hair: Once weekly.
- Normal hair: Every 1 to 2 weeks.
- Dry, curly, or high porosity hair: Every 2 to 4 weeks, then deep condition.
- Hard water or swimmer: Weekly maintenance is fine. For stubborn mineral staining, alternate occasionally with a true chelating wash as needed.
Color-care tips with No.4C:
- Wait at least 3 days after a permanent color service before clarifying. For direct or semi-permanent vivid shades, wait a full week.
- Use the lather as your lengths cleanser. Apply most product at the scalp and let the suds run through mids and ends instead of scrubbing them.
- Pair with a rich conditioner or mask to guard the ends. If needed, work a pea of conditioner into the last inch of hair before you shampoo as a buffer, then fully condition after.
Pros and cons
Here is what stood out after repeated testing on color-treated, fine, and curly hair types.
Pros
- Deep, satisfying clean that removes mineral film, dry shampoo residue, and heavy styling layers.
- Color respectful when used as directed. It brightens highlights and restores shine instead of dulling.
- Light, airy finish with extra root lift. Great for fine hair that collapses easily.
- Sulfate free and pH balanced, so it feels less punishing than old-school clarifiers.
- A little goes a long way. The dense lather stretches easily with added water.
- Includes chelating helpers, so it is more effective in hard water than a typical daily shampoo.
Cons
- Can feel drying on high-porosity or very damaged ends if you do not follow with a mask.
- Lower slip when wet, so detangling relies on your conditioner step.
- Premium price for a product you will not use every wash.
- Not ideal for fresh fashion colors or frequent use after a keratin treatment.
- May not fully clear severe mineral staining on its own. Occasional chelating may still be needed.
Final verdict
Olaplex No.4C is a standout clarifying shampoo for anyone who wants a true reset without the usual color crash and strawlike afterfeel. It cuts through buildup, lifts hard water haze, and restores bounce, yet remains surprisingly respectful of salon color when used weekly and paired with a conditioner or mask. If you have fine or normal hair that gets weighed down, it is an easy yes. If your hair is dry or highly processed, use it less often and lean on a deep conditioner afterward. For stubborn mineral or swimmer’s buildup, keep a dedicated chelator in your back pocket, but for week-to-week maintenance, No.4C is the comfortable, reliable clean you will actually look forward to using.
See also
If you are deciding between a clarifier like No.4C and a true mineral lifter, read our primer on Chelating vs Clarifying Shampoo: What Each Does and When to Use. If preserving salon tone is your top priority, we also tested gentle but effective options in Best Clarifying Shampoos That Don’t Trash Color-Treated Hair.
When heavy residue is the problem, browse our favorites in Best Clarifying Shampoos for Removing Buildup. Hard water plays a big role in dullness too, and the basics in How Water Hardness Affects Skin: Cleanser Choice and Rinse Tips apply to hair care as well. If hair feels a little limp after a deep clean, the right strengthening mask from Best Protein Treatments for Damaged Hair: Strength Without Stiffness can restore bounce without stiffness.
FAQ
Is Olaplex No.4C safe to use on freshly colored hair?
It is color safe, but timing matters. Wait at least 3 days after a permanent color service so the cuticle can settle. For direct dyes and vivid semi-permanent shades, wait a full week because clarifying can nudge pigments that sit on the surface. When you do use it, focus most of the product on the scalp and let the lather cleanse your lengths.
How often should I use No.4C for my hair type?
Oily or fine hair usually does best with weekly use. Normal hair can use it every 1 to 2 weeks. Dry, curly, or highly porous hair should keep it to every 2 to 4 weeks and follow with a rich conditioner or mask. If you swim or live with hard water, weekly is fine, but consider an occasional dedicated chelating wash for stubborn mineral issues.
Will No.4C remove hard water minerals or swimmer’s green?
It helps remove mineral film and keeps tone bright, especially for blondes, thanks to chelating and sequestering helpers in the formula. For severe copper or iron staining and swimmer’s green, you may still need a true chelating session. Use No.4C for ongoing maintenance and a chelator as needed for tougher cases.
What should I pair with No.4C to avoid dryness?
Always follow with a hydrating conditioner or a deep mask to restore slip and softness. High-porosity or highlighted ends benefit from a richer mask after clarifying. You can also try a pea-size buffer of conditioner on the last inch of hair before you shampoo, then fully condition after, to protect very delicate ends.
How much shampoo should I use, and is a double cleanse necessary?
Start with a quarter-size amount for shoulder-length hair and adjust based on density. Add water to expand the lather before adding more shampoo. For heavy dry shampoo or styling buildup, a second quick lather focused on the scalp is helpful. Let the first pass sit for 30 to 60 seconds if you are dealing with hard water residue.
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