Breaking Down the Olaplex Line: What Each Product Does and How to Use It

If you’ve ever been curious about those numbered Olaplex products, you’re not alone. Olaplex has a whole lineup (No.0 through No.10, plus a special No.0.5) designed to repair and pamper your hair. In this casual guide, we’ll break down each product’s benefits and how to use them in your everyday hair routine. Whether you’re dealing with damage, frizz, brassiness, or just want healthier hair, here’s what each Olaplex product can do for you.

Olaplex No.0 - Intensive Bond Building Hair Treatment

What it is & benefits: Olaplex No.0 is essentially the primer for your at-home hair repair. Think of it as the booster that preps your hair for deeper repair when used with Olaplex No.3. It’s a lightweight, watery treatment that works at a molecular level to rebuild broken hair bonds, intensifying the effectiveness of No.3. By using No.0 first, you strengthen strands and reduce breakage even more, especially if your hair is highly damaged. It’s suitable for all hair types - if your hair is super damaged, you’ll notice the most dramatic improvement as it helps make your hair stronger and healthier from the inside out.

How to use: No.0 is step one of a two-part bond-building routine. On dry hair, saturate your hair from root to tip with No.0 (the nozzle makes this easy) and let it sit for about 10 minutes. Don’t rinse! Next, apply Olaplex No.3 directly on top of the still-damp No.0 in your hair and comb it through to distribute. Let that duo sit for another 10 minutes (or longer if you like), then rinse out and shampoo and condition as usual (Olaplex No.4 and No.5 are recommended). For most folks, doing this No.0 + No.3 treatment once a week is plenty, but if your hair is very compromised, you can use it 2-3 times per week for extra TLC.

Olaplex No.3 - Hair Perfector Repairing Treatment

What it is & benefits: No.3 Hair Perfector is Olaplex’s superstar product - the at-home bond-building treatment beloved for fixing damaged hair. Despite often being mistaken for a conditioner, it’s actually a pre-shampoo treatment that repairs broken disulfide bonds in the hair, making your mane stronger and healthier. In plain English: it helps rebuild the hair structure that gets weakened by things like bleach, heat styling, or general wear-and-tear. After using No.3, people notice their hair feels softer and looks shinier and less frizzy, because it literally works to reverse damage and strengthen the hair from within. In fact, it’s clinically proven to leave hair 3 times stronger after just one use (when followed with the Olaplex shampoo). It’s formulated for all hair types - basically, if you have hair, No.3 can probably help improve its look and feel. It’s the go-to weekly ritual for maintaining your healthiest-looking hair.

How to use: Using No.3 is super easy, but remember: apply it before shampooing (this is key, since it’s not a conditioner you use after washing). Here’s the typical routine: Dampen your hair (if it’s not already wet) and towel-dry out any excess water. Apply a generous amount of No.3 from roots to ends - enough to thoroughly saturate your hair. Let it sit for at least 10 minutes (Olaplex notes you can start seeing benefits in as little as 3 minutes, but leaving it the full 10 or longer gives a deeper treatment). After time’s up, rinse it out, then follow with your regular shampoo and conditioner (for best results, use No.4 and No.5 after). Use No.3 about once a week to keep your hair in tip-top shape, or a bit more frequently if your hair is very damaged and needs extra love. (Just note that leaving it on beyond 10 minutes won’t magically make it work better - Olaplex says you’ve gotten the max benefit by the 10-minute mark, so no need to sleep in it overnight.)

Olaplex No.4 - Bond Maintenance Shampoo

What it is & benefits: Olaplex No.4 is a daily shampoo that not only cleanses your hair, but also repairs and strengthens it at the same time. It’s a highly concentrated, sulfate-free shampoo, so a little goes a long way and it gives a rich lather without stripping your hair. The big benefit of No.4 is bond maintenance - every time you wash, it’s helping to reduce breakage and reinforce the hair’s strength. Over time, that means less breakage, smoother texture, and more manageable hair with lots of shine. It’s color-safe and works on all hair types, from straight to curly, fine to coarse. Essentially, No.4 is your everyday repair shampoo - it gently cleans while infusing your hair with moisture and nourishment so you’re not left with that dry “stripped” feeling after washing. If you have damage or dryness, this shampoo helps your hair look healthier with each wash.

How to use: Use No.4 like a typical shampoo - get your hair thoroughly wet, then massage a small dollop into your scalp and hair. It lathers up a lot (thanks to a coconut-derived surfactant blend) so add a bit of water and work it through all your hair. Rinse out completely. Because it’s so concentrated, you might find you need less than your usual shampoo dose. Follow up with a good conditioner (Olaplex No.5 is the perfect match). You can use No.4 whenever you wash your hair - it’s gentle enough for everyday use or a few times a week, depending on your routine. Over time, you’ll notice your hair feeling softer and looking shinier and stronger with consistent use.

Olaplex No.4P - Blonde Enhancer Purple Toning Shampoo

What it is & benefits: No.4P is a violet-tinted toning shampoo designed especially for blondes, silvers, or anyone with lightened hair. If you battle brassiness or yellow tones, this is your secret weapon. What makes 4P special is that it neutralizes brass while repairing and hydrating your hair, all in one step. It’s a highly concentrated purple shampoo that creates a luxurious lather to cleanse your hair and deposit just enough violet pigment to cancel out unwanted yellow/orange hues, making your blonde or gray hair brighter and cooler in tone. Unlike some purple shampoos that can be drying, 4P is formulated with Olaplex’s bond-building ingredients, so it actually repairs damage and keeps hair hydrated from roots to ends while toning. In fact, it’s scientifically proven to get hair 3 times brighter compared to other top purple shampoos after one use. The result: your blonde stays bright and icy, your grays look shiny and clean, and your hair feels soft and strong (not brittle, which can happen with harsher toners).

How to use: Use No.4P in place of your regular shampoo whenever you need to tone down brassiness. For most blondes, 2-3 times a week is enough to keep the yellow away, but you can adjust as needed. Wet your hair, then work 4P shampoo through your hair, focusing on the areas where you see brassiness. You can leave it on for a minute or two (up to 5 minutes for extra toning) before rinsing to let those purple pigments work their magic. Be sure to rinse thoroughly, and then follow up with a conditioner (Olaplex No.5 or the companion No.5P Blonde Toning Conditioner if you have it). Keep an eye on how your color looks - if your hair starts looking too ashy or slightly violet, cut back on frequency. Used correctly, 4P will keep blondes bright and brass-free, all while giving you the bond-building benefits of the regular No.4 shampoo.

Olaplex No.5 - Bond Maintenance Conditioner

What it is & benefits: No.5 is the conditioner step of the Olaplex system, formulated to moisturize and repair without weighing your hair down. It’s a rich, creamy conditioner that targets damage and dryness - after shampooing, No.5 helps strengthen your hair, reduce frizz, and make it easier to manage and detangle. The bond-building technology means it’s actually mending broken bonds in your hair each time you condition, leading to less breakage over time. Key benefits include leaving the hair softer, smoother, and shinier - basically that healthy hair look - and it works for all hair types (it hydrates dry, coarse hair but is lightweight enough not to overwhelm fine hair). In a nutshell, Olaplex No.5 makes your hair feel velvety without any heavy residue, and it keeps strengthening your strands with every use. It’s color-safe and silicone-free, relying on ingredients like panthenol and oils to moisturize and add shine. If you want a must-have daily conditioner for strong, shiny hair, No.5 is it.

How to use: After shampooing (with No.4 or your shampoo of choice), apply a generous amount of No.5 conditioner to your hair, focusing on the mid-lengths and ends (where you typically need the most conditioning). Work it through and leave it on for 1-3 minutes to let it penetrate and do its thing. Then rinse well. You’ll likely notice your hair instantly feels silkier as you rinse it out. No.5 can be used every time you wash your hair - it’s gentle and hydrating enough for daily use. For best results, use it as a system with No.4 shampoo; together they’ve been shown to make hair up to 90% smoother and easier to detangle after just one use (when paired with the weekly No.3 treatment). Consistent use of No.5 will keep your hair strong, glossy, and healthy-feeling without that coated feeling some heavy conditioners leave behind.

Olaplex No.6 - Bond Smoother (Leave-In Styling Cream)

What it is & benefits: No.6 Bond Smoother is a leave-in styling cream that doubles as a treatment - it makes your hair smoother and frizz-free while also strengthening it. If you struggle with frizz or unruly hair, No.6 is a game-changer: it’s clinically proven to control frizz for up to 72 hours. The texture is a lightweight, velvety cream that you leave in your damp hair (and even use to tame dry hair), and it softens, hydrates, and defends your hair against humidity without weighing it down. It basically acts like an invisible shield against poofiness - great for blowouts or air-drying curly hair to be more defined. No.6 also provides heat protection up to 450°F (232°C), so it’s perfect to apply before blow drying or using hot tools. With ingredients like coconut oil, vitamin E, and sunflower oil, it adds a subtle shine and smoothness to the hair surface. In short, Bond Smoother makes hair easier to style, keeps it sleek and flyaway-free for days, and continuously repairs damage and breakage in the background. It works on all hair types, but those with frizz-prone, curly, or coarse hair will especially adore this product.

How to use: You can use No.6 in a few ways. The primary method is as a leave-in cream on clean, damp hair. After washing and conditioning, apply a small amount (start with a pea-sized dollop or about one pump) to your mid-lengths and ends. A little goes a long way - you can always add more if needed. Comb it through or rake with your fingers to distribute, then style as usual. You can air dry (No.6 will help define and soften air-dried styles without frizz) or blow-dry for a smoother finish. Feel free to cocktail a couple drops of No.7 Bonding Oil with No.6 for extra shine and frizz control - they’re often used together for a “bomb” combo of smoothness and shine. Another great thing about No.6: you can also use it on dry hair to tame flyaways and touch up frizz. For example, rub a tiny bit between your fingers and smooth it over any fuzzy bits or ends that need sleeking down. Because it provides extended frizz control, you likely won’t need to reapply it until your next wash (hence that 72-hour claim). It’s basically a styling and treatment hybrid, so leave it in and let it work its magic as your hair dries - you’ll get a polished look that lasts for days.

Olaplex No.7 - Bonding Oil

What it is & benefits: Olaplex No.7 is a weightless finishing oil that delivers instant shine, softness, and major smoothness to the hair. If your hair lacks luster or tends to get frizzy, a couple drops of this highly concentrated oil will make a noticeable difference. It boosts shine and color vibrancy (great for highlighting the tones in colored or natural hair) and tames frizz and flyaways without any greasy feel. Despite being an oil, it’s very lightweight - it absorbs quickly and won’t weigh down even fine hair when used sparingly. No.7 is also a heat protectant up to 450°F, so you can use it before heat styling to safeguard your strands. Beyond cosmetic shine, it actually helps strengthen the hair to minimize breakage over time, thanks to the bond-building ingredient and nourishing oils in the formula. Key ingredients include a blend of sunflower seed oil, vitamin E, and other botanicals that condition the hair and add 125% more shine (as their lab tests showed on bleached hair). Think of No.7 as the finishing touch for sleek, glossy hair that also keeps your hair healthy - it’s perfect for all hair types whenever you want that extra glassy shine and silky feel.

How to use: No.7 Bonding Oil is super versatile. Because it’s so concentrated, you only need 1 to 3 drops per use (depending on your hair length and thickness). The bottle has a clever little drop-dispensing design: invert the bottle and gently tap the bottom with your index finger to release a drop at a time. Rub those drops between your palms and then smooth the oil through either damp or dry hair. On damp hair, you can use it as a heat protectant before blow drying or styling - it will help with a sleeker blowout and protect from heat damage. On dry hair, apply it as a finishing oil after styling to add shine and tame any last flyaways. Pro tip: you can also mix No.7 with No.6 Bond Smoother in your hand and apply together on damp hair - this combo gives insane smoothness, frizz control, and shine (stylists love this trick). No.7 can be used daily since it’s lightweight - feel free to apply a drop on dry ends or frizzy spots each day to refresh shine and softness. It absorbs cleanly with no oily residue, so your hair will just look glossy and feel silky. Essentially, use No.7 whenever your hair needs a little extra shine or frizz-taming, and enjoy the added bonus of heat protection and bond repair it provides.

Olaplex No.8 - Bond Intense Moisture Mask

What it is & benefits: Olaplex No.8 is a concentrated deep-conditioning mask that gives your hair a powerful dose of moisture and repair in about 10 minutes. This is the product to reach for when your hair is feeling particularly dry, brittle, or dull. No.8 is packed with ingredients like hyaluronic acid, ceramides, avocado and rosehip oils - so it provides intense hydration to quench dry, dehydrated hair. The benefits are impressive: it replenishes moisture, making hair noticeably softer and smoother, and it strengthens the hair to reduce breakage. After a treatment, hair tends to have more shine and even a bit more body, because hydrated hair has more elasticity and life. Olaplex’s bond-building tech is infused in this mask as well, so while it conditions, it’s also rebuilding broken bonds for healthier strands. In fact, in studies, No.8 made hair 2x shinier and 4x more moisturized, with significantly improved smoothness and body after one use. It’s suitable for all hair types - even fine hair can use it (just apply mid-length to ends if you worry about volume). Basically, No.8 leaves your hair ultra-soft, silky, and manageable, and helps repair damage - like a luxurious spa day for your hair each week.

How to use: Use No.8 in place of your regular conditioner about once a week (or every other wash, depending on how much love your hair needs). After shampooing, skip your normal conditioner and instead apply No.8 mask generously to your lengths and ends (you can use one or two pumps from the bottle - add more for long or thick hair). Distribute it evenly; you can comb it through with your fingers to make sure every strand gets coated. Then leave it on for about 10 minutes (you can clip your hair up and relax during this time) and rinse out thoroughly. There’s no need to follow with a conditioner after, since this mask is your conditioning step. Immediately, you should feel how much smoother and easier to detangle your hair is (No.8 gives about 90% better conditioning and detangling according to Olaplex’s test when used with No.4 shampoo). Style as usual, and enjoy the newfound silkiness and shine. For very dry or damaged hair, some people use No.8 more often (2-3 times a week), but for most, weekly use keeps hair in that sweet spot of deeply moisturized without overdoing it. Consistent use will strengthen your hair over time, thanks to the bond-building aspect, meaning less breakage and more resilient, glossy hair.

Olaplex No.9 - Bond Protector Nourishing Hair Serum

What it is & benefits: No.9 is a leave-in hair serum that focuses on protecting your hair from everyday damage while making it easier to style. It’s a weightless, silicone-free serum (more like a light cream-gel consistency) that you apply to damp hair. The big benefits: it provides a protective shield against pollution for 48 hours and guards your hair from heat styling up to 450°F. In other words, it’s like an antioxidant + heat protectant for your hair, helping to fend off free radicals and environmental damage that can cause dryness or color fading. No.9 also makes hair smoother and less tangly, fighting static and taming those flyaways. It gives a satin shine finish once your hair is dried, so your hair looks glossy but not greasy. Because it’s so lightweight and silicone-free, it layers well with other products and doesn’t leave buildup. Think of No.9 as a primer for styling: it detangles, provides a bit of light hydration, and protects your hair, which in turn leads to longer-lasting styles with less frizz. All hair types can use it, but it’s especially useful if you blow-dry or flat iron frequently, or if you live in a city with pollution - basically, it keeps your hair feeling cleaner and silkier between washes. (Fun fact: Olaplex differentiates No.9 from No.6 by saying No.9 is primarily for heat/pollution protection and manageability, whereas No.6 is for frizz control and smoothing - and you can even use them together for maximum benefits.)

How to use: Apply No.9 to clean, damp hair as the first step before any styling products (you can use it alone or before layering on things like No.6 or mousse, etc.). Use a small amount (about a pea to dime-sized to start) and work it in from the ends upward towards the roots. You don’t need to douse your hair - just enough to lightly coat. Then style as you normally would. If you’re air-drying, No.9 will give a soft, touchable finish with less frizz. If you’re blow-drying, it will help your blowout turn out smoother and with shine. For curly or wavy hair, you can even scrunch it in and then diffuse - it helps define waves/curls without crunch. Since it’s lightweight, you can also use a drop on dry hair to smooth the ends or tame static (though usually it’s meant for wet hair). There’s no strict limit on how often to use it - apply it any time you wash your hair. Many people will use No.9 every wash day to get that daily protection. And yes, you absolutely can cocktail it: for instance, apply No.9 first for heat protection, then a bit of No.6 for extra frizz control if needed - they’re actually recommended to be used together if you want both benefits. Overall, using No.9 regularly means your hair is shielded from a lot of the daily stressors, so you’ll notice it stays smoother, shinier, and healthier in the long run.

Olaplex No.10 - Bond Shaper Curl Defining Gel

What it is & benefits: Olaplex No.10 is a newer addition tailored for those with waves, curls, or coils. It’s a curl defining gel that provides a flexible, medium hold to shape your curls without any crunchy or sticky residue. Picture bouncy, defined curls that still feel soft - that’s what No.10 aims for. This gel is also an anti-frizz formula, so it keeps your curls smooth and controls frizz for up to 72 hours, even in humidity. It’s packed with bond-building goodness, meaning it strengthens your hair’s curl structure from within (great for maintaining healthy curls) and protects against heat up to 450°F. So if you diffuse with a dryer, your hair is covered on the heat protection front. No.10 also contains a “Curl Retention Compound” with plant-based ingredients that create a curl-locking barrier - this helps enhance your natural curl pattern and keep the definition lasting beyond day one. Users have found they get 3x better curl retention with this gel (so curls don’t droop as quickly) and it’s very humidity-resistant. Importantly, it’s not a drying gel; it actually has coconut and avocado oils (a “hair milk” blend) that nourish and condition, so your curls stay hydrated and touchably soft. Essentially, No.10 Bond Shaper is the one-and-done product for defined, shiny, frizz-free curls that still move and feel natural.

How to use: Start with clean, wet hair (for best results, shampoo and condition with your usual products - Olaplex No.4 and No.5 or your preferred curl-friendly duo). Apply No.10 in sections for even distribution: take a small amount of gel in your palms, then work it through a section of wet hair from root to tip. Repeat section by section until all your hair has gel. The amount you use will depend on your hair length/thickness - start small, you can always add more if needed. After applying, scrunch your hair in an upward motion to encourage your curl pattern (this helps form the curls). You can also use any curl defining technique you like (praying hands, finger coiling, etc.) with this gel; it has a nice slip, meaning it detangles and glides through easily. Then either air dry or diffuse your curls. If air-drying, just let the curls set; the gel will dry with a cast (a slight crunch) which is normal. Once your hair is completely dry, scrunch out the crunch - basically squeeze and scrunch your curls to soften that cast and reveal soft, bouncy curls with no residue. If you diffuse with a blow dryer, you can dry about 80% and then let air-dry the rest to minimize frizz, then scrunch out the cast. The result is well-defined curls that are shiny and frizz-protected. No.10’s hold is flexible, so your curls will still have movement and won’t feel “glued.” And thanks to the bond-building aspect, using this gel over time also means stronger curls - Olaplex even notes it helps revive the curl pattern for “great curl days every day” by strengthening the hair’s internal bonds. You can use No.10 alone, or layer a bit of No.9 serum underneath for extra protection, and a few drops of No.7 oil after drying for added shine (this layering is totally optional, depending on your routine). Enjoy your soft, defined curls!

Olaplex No.0.5 - Scalp Longevity Treatment

What it is & benefits: Olaplex No.0.5 is a special scalp serum designed to nurture your scalp’s health - think of it as skincare for your scalp. The idea here is that a healthier scalp grows healthier hair. This is a weightless, leave-in serum (so it’s not oily or heavy) that immediately hydrates and soothes the scalp on contact. If you have issues like dryness, tightness, or irritation on your scalp, No.0.5 provides instant relief with ingredients like hyaluronic acid for hydration and a calming botanical blend (including lavender and Tasmanian pepper extracts) to reduce irritation and redness. Beyond quick hydration, it also works long-term to strengthen the scalp’s barrier and balance the scalp microbiome. Why is that important? A strong scalp barrier means less irritation and a better environment for hair to grow, and a balanced microbiome means the scalp isn’t overrun by bad bacteria or fungi that could lead to dandruff or scalp issues. Olaplex even highlights that the scalp ages faster than the skin on your face (up to 6x faster) due to factors like sun and hard water. This serum is packed with antioxidants and ceramides to combat those aging factors - essentially protecting against accelerated scalp aging (hence the “longevity” name). The payoff for your hair: using No.0.5 leads to softer, shinier, visibly healthier hair over time, because a well-nourished scalp produces better-quality hair. In a consumer study, people noticed their hair was visibly healthier and softer after 4 weeks of use. So, if you’ve been focusing on hair masks and oils but neglecting your scalp, No.0.5 is the product to level up your routine and care for the root (literally) of hair health.

How to use: You’ll want to apply No.0.5 directly to your scalp - it comes with a needle-nose applicator that makes this easy. You can use it on either damp or dry hair (clean scalp is ideal, like after a shower, but you can also use it on non-wash days). Part your hair in sections and gently squeeze the bottle to apply a few drops along each part, targeting your scalp skin. Olaplex recommends doing about 3-4 sections to cover the crown and back of your head, but you can do more sections to hit everywhere (sides, hairline, etc.) if needed. Once applied, massage it in with your fingertips to help the serum absorb and stimulate circulation. There’s no need to rinse it out - it’s a leave-in treatment, and it absorbs without leaving any residue or greasiness. You can then style your hair as usual. For frequency, use No.0.5 about three times a week for best results. It’s gentle enough to use daily if you want; some people might use it every night as an overnight scalp treatment (which is totally fine). Because it’s lightweight, it won’t make your hair oily, so you don’t have to worry about it messing up your styling. With regular use, you should notice your scalp feels more comfortable (less dryness or itch) and, after about a month, potentially see that your hair looks healthier at the roots and overall. Consider No.0.5 your scalp’s new BFF - a little self-care step that can yield big benefits for your hair’s future growth and glow.

Olaplex has a solution for almost every hair woe, from rebuilding broken bonds and banishing frizz, to keeping blondes bright and even caring for your scalp. The numbering can seem confusing at first, but each No.0-No.10 (and 0.5!) has a unique role. You can mix and match them in your routine depending on your hair’s needs - many people use several Olaplex products together for a comprehensive hair care regimen. Hopefully, this breakdown makes it easier to decide which products might be right for you. Whether you’re doing a weekly repair treatment with No.0 + No.3, maintaining with the No.4 and No.5 wash duo, smoothing with No.6 and No.7, enhancing curls with No.10, or giving your scalp some love with No.0.5, you’re on your way to stronger, healthier, happier hair. Enjoy your good hair days! 💁‍♀️