My hair and I have a love-hate relationship. While I enjoy my length and fullness, the untamable frizz and coarse texture are things I can never get past. to the point where I’m constantly blow drying it straight and my 2B curls rarely see the light of day. I’ve never color-treated my hair before, but I have subjected it to its fair share of trauma - namely, months of chlorine exposure, more than two decades of heat styling and a lifetime of tight hairstyles. Needless to say, my hair is severely dry.
Recently, Olaplaex sent me its No.5 Moisturize & Mend Leave-In Conditioner, a formula that sounded like it could reset my frizz-prone, dehydrated hair. Below, I share my experience using the product - which debuted in August 2024 - including its ingredients, who it’s best for and how to apply.
What is Olaplex No.5 Moisturize & Mend Leave-In Conditioner?
Olaplex No.5 Moisturize & Mend Leave-In Conditioner
As pioneers in the hair care space, Olaplex put bond building technology - that is, technology designed to strengthen and rebuild weakened hair bonds - on the map. Hair bonds are what give the hair its shape, durability, elasticity and shine, and coloring, chlorine exposure, chemical treatments, daily styling and humidity can damage them. Olaplex products, including its No.5 Moisturize & Mend Leave-In Conditioner ($32) work at a molecular level to repair damage, lock in hydration and protect it from moisture loss. The leave-in conditioner also uses a sealing complex to help mend split ends. While it works for all hair types, it’s especially beneficial for those with dry, damaged hair that’s in need of moisture, according to Olaplex.
Olaplex has another leave-in product, the No.6 Bond Smoother, which also aims to hydrate and smooth the hair, but it’s more of a styling cream that hones in on frizz control and definition, while the leave-in conditioner hydrates, repairs, mends split ends and protects hair from damage, according to brand.
How I tried the Olaplex No.5 leave-in conditioner
Over the course of three weeks, I tried the leave-in conditioner in several ways: on air dried and damp hair, on damp hair that I then heat styled and in between washes on already-styled hair to refresh. Leave-in products typically clump up on my curls, leaving behind residue and greasiness, so I was determined to see how this product fared particularly when I blow out my hair.
I used the leave-in conditioner on both damp and dry hair and it's much less frizzy when I use it. (Before photo on the left, after on the right). Courtesy Michelle Rostamian
For reference, my Middle Eastern 2B hair is extremely dry from scalp to ends. It’s also prone to frizz - even when I blow it out, it frizzes up when exposed to the slightest humidity. My typical hair care routine involves using a shampoo and conditioner combination (right now that’s the Morrocanoil Hydrating Shampoo & Conditioner, the Moroccanoil Treatment Original and the Drybar Liquid Glass High-Gloss Finishing Hair Serum). After blowing out my hair, I usually follow up with a lightweight hair spray, like the Drybar Seltzer Spritz Flexible Hold Hairspray.
Olaplex recommends starting with one pump if you have fine hair and two pumps for medium to coarse hair, adding more as needed onto clean, damp hair. Then, you can proceed to air dry or heat style. On hair wash days, I use three pumps on my long, thick hair, working the product starting just below the roots and all the way to my ends (avoiding my scalp). When my blown out hair needs frizz control, I applied one to two pumps from the mid-length to my ends and my hair looks freshly styled.
My experience with the Olaplex No.5 Moisturize & Mend Leave-In Conditioner
Despite Olaplex’s popularity - particularly its No.3 Hair Perfector and No.7 Bonding Oil I’ve never remained committed to the brand because I always assumed it was geared more for those with color-treated hair. That’s why when I saw that the leave-in conditioner was made specifically for anyone with dry hair (even those with virgin hair), I was instantly drawn to it.
What I like
- Doubles as a styler: After testing this leave-in for a few weeks, it has far exceeded expectations. The formula defines my curls and makes them appear more uniform without weighing them down, and it instantly removes all traces of frizz upon application, making my hair appear sleeker and shinier. I’ve worn my hair in its natural state several times since incorporating this into my routine, and it feels good knowing that it’s enhancing my curls while also repairing and protecting my hair from damage.
- Moisturizes dry ends: Ends look hydrated and healthy; it almost feels like a lightweight hair mask for my ends. It helps when getting a blow out and makes curls more maskable, while still allowing for straight styles.
- Easy application: The pump applicator disperses just the right amount of product that doesn’t leak, and the pump has a slight grip to it, helpful if hands are slick from product. It doesn’t feel too sticky, and there’s little need to rinse hands afterward, making it gym- and car-friendly.
Drawbacks to keep in mind
- Not travel-friendly: Packaging is bulky and there’s no mini option, which can be inconvenient for trips despite the bottle being TSA-friendly.
Who is Olaplex’s No.5 leave-in conditioner best for?
- Overall, I highly recommend Olaplex’s leave-in conditioner for anyone struggling with hair damage or those looking to reintroduce moisture into their hair. It’s suitable for all hair types (fine included) since it doesn’t weigh the hair down or make it feel greasy. It’s great for those with bleached, colored or otherwise chemically treated hair, and can work for those with wavy to slightly curly hair types who want to hydrate and define curls.
- Scent-wise, the formula has a sophisticated bubblegum aroma that lingers in my hair even after heat styling, so if you’re not someone who prefers scented products this won’t be for you.
- Pricing: The formula is more costly than drugstore options, with Olaplex No.5 priced at about $32 for 3.3 fl oz. Alternatives include Not Your Mother’s Tough Love ($11) or Eva NYC Mane Magic 10-in-1 ($16). For a more budget-friendly option, SheaMoisture Bond Repair Leave-In Conditioner ($13) may be worth considering.
Why trust NBC Select?
I have more than 10 years of experience covering beauty and skin care topics and frequently try and review new products. Today I’m reviewing Olaplex No.5 Leave-in Conditioner, one of the newest products by Olaplex. I’ll be looking at it from the angle of those with curly hair. Is it worth the hype? Does it love your curls like a trusted friend?
Table of Contents
What is Olaplex No.5 Leave-in Conditioner?
Why Olaplex No.5 Leave-in Conditioner is designed to deeply moisturize your hair, protect it from damage, and restore strength-all in a lightweight leave-in cream formula. It contains Olaplex’s patented bonding technology, which helps repair broken bonds and prevent further breakage. Added to this, it even offers heat protection, so you’ll be reassured if you occasionally diffuse your curls. A product that does damage repair and protection? Why Olaplex No.5?
Curly hair needs love, and by love, I mean moisture. Curly hair is naturally drier because its shape prevents the scalp’s oils from travelling down the hair shaft easily. The Olaplex No.5 Leave-in Conditioner is extremely hydrating. Heat-styling, rough detangling, UV exposure, and even colouring your hair can compromise curl integrity. Thanks to Olaplex’s patented active ingredient-Bis-Aminopropyl Diglycol Dimaleate-No. 3. If you love diffusing your curls to give them that extra definition and bounce, having heat protection is non-negotiable. This leave-in conditioner has you covered so your curls stay safe from heat damage (and still look fabulous).
Not only does it hydrate and protect, but Olaplex No.5 is suitable for those following CGM rules, YES, this one can be incorporated into the Curly Girl Method! It’s free from sulfates, so it won’t strip your strands. Squeeze out excess water and apply one pump of Olaplex No. 5 to damp hair. I’ve been using this for a couple of months and I love it! The formula is lightweight and it is very moisturising. I find that it is the perfect prep for styling products. It absorbs easily and smoothes my frizzy hair. The fact that it has heat protection is such an added bonus; one less thing to worry about!
I’ve tried almost all of the Olaplex line and this is my favourite so far. I also like the scent. Price Point: At around $30 per bottle, it’s definitely an investment. Olaplex claims that this product ‘mends split ends’. Now I don’t want to be the person to say it doesn’t but I think this sets expectations very high! If you want healthy, bouncy curls that are protected from damage and frizz, Olaplex No.5 leave-in conditioner is definitely worth trying out. Follow Me On Instagram For Daily Wavy & Curly Hair Tips! This leave in conditioner is perfect for my coarse, curly hair. One pump is plenty and it leaves my hair so soda and manageable. My curls are well defined and frizz free.
One reviewer noted: “Not only does it nourish and hydrates your hair but if used prior to blow drying, it acts as a nice protective coating.” It goes on with just one pump from the applicator, and not only holds down those fly away ends, but also conditions and protects from heat damage. It does not weigh hair down, and actually makes your hair healthier in appearance, too.
Hairstylists and colourists across the country frequently combine Olaplex with professional dye to protect hair during the colouring process and treat damage post-bleaching. More recently, the haircare brand has expanded into styling products and, perhaps even more excitingly, into lash growth serums. For more of a brand overview, check out our roundup of the best Olaplex products here.
INTRODUCING THE NEW OLAPLEX N°·5 LEAVE-IN™ MOISTURIZE & MEND LEAVE-IN CONDITIONER
Overall, I do think this launch is a good one from Olaplex. Its styling products are nice but haven't all blown me away in the past, however, I’ve consistently returned to the No.5 Leave-In Conditioner with each wash since I got my hands on it. It’s important to manage expectations, however-it's not going to give you really rich nourishment, so if your hair is thicker and needs a lot of moisture you’d likely need more than this product alone. My strands are medium-to-fine but incredibly prone to dryness, so I get the best results when I layer it with another spray. Olaplex is one of our most in-demand hair brands and rightly so.
Since then, Olaplex has expanded its portfolio of products to include the best-selling No.7 Bonding Oil, a triple-action styling oil that restores, protects and improves the softness of the hair and the iconic No.4 Bond Maintenance shampoo, which gently cleanses hair and tames frizz. We asked two Space NK team members with differing hair types to answer the question: is this Olaplex’s best product yet? Having had my hair professionally bleached from dark brown to light blonde for over three years, I’ve become quite familiar with the damage that comes with it - dryness, brittleness and worst of all, split ends. As a dedicated fan of Olaplex’s award-winning formulas, I had high hopes the No.5 Leave-In Conditioner would restore moisture and manageability to my hair. This leave-in conditioner has a creamy, lightweight texture that spreads seamlessly through the hair and coats each strand in just one pump of product. After using this conditioner for a few weeks, I’ve noticed a significant improvement in the health of my hair. My split ends have been smoothed - meaning I can grow my hair out past my shoulders without needing my monthly trim - and my usual frizz has reduced considerably. I wouldn’t say this is a miracle cure that will heal colour-treated hair and repair split ends overnight. But it is much more effective than other leave-in treatments I’ve tried and delivers on its promises, providing much-needed hydration, protection and resilience to damaged hair.
My curly hair can be quite tricky to tame, especially when it comes to maintaining moisture, definition and frizz control. So, finding a product that actually wraps each curl in hydration without weighing them down is a serious game-changer. The No.5 Leave-In Conditioner from Olaplex has a rich, but lightweight texture that distributes evenly through my hair without leaving any sticky or greasy residue behind, which is often my main concern with leave-in formulas. From the first use, I noticed my curls were enhanced with more bounce, shine and remained frizz-free against the humidity of city heat and stuffy commutes. The scent is another win: it’s fresh and subtle with a slightly minty note that lingers long after I’ve dried my hair. Olaplex markets this product as suitable for all hair types and I would have to agree. My dry, split ends were replenished with hydration and strength, which supported the shape and elasticity of my curls. This leave-in conditioner is definitely an investment, but if you struggle with split ends and frizzy strands like me, it’s worth the splurge. Proving it performs well on curly and colour-treated hair types, this product impressed with its ability to sculpt curls, provide long-lasting hydration and repair dry, damaged ends over just a few weeks. The creamy formula is cost-effective too, one pump is just enough to coat each strand without making hair heavy - which is a major plus for finer hair textures.
While you can use Olaplex No.5 Leave-In conditioner on its own, the brand recommends pairing it with its maintenance-focused formulas to maximise the bond-building benefits of its magic ingredient. Olaplex has quickly amassed a loyal legion of followers with hero products like the No.3 Hair Perfector which transforms dry, brittle strands into soft, shiny and more resilient hair. Hairstylists and colourists across the country frequently combine Olaplex with professional dye to protect hair during the colouring process and treat damage post-bleaching. More recently, the haircare brand has expanded into styling products and perhaps even more excitingly, into lash growth serums. For more of a brand overview, check out our roundup of the best Olaplex products here.
tags: #olaplex #leave #in #conditioner #reviews