Editor's TipEditor's Tip

For best results, condition with Number 4™ Reconstructing Masque.

Number 4 Hair Care

Birchbox Breakdown

There was a time when we were a bit skeptical about hair oil—the last thing we wanted was a greasy, weighed down ’do. These days, however, we can't imagine a haircare routine without it. This strand-saving elixir gives drab, dull hair a coveted movie star shine (plus a whole host of reparative benefits). Our oil-free days are officially over.

How it Works

Number 4™’s Liquid Complex Culture uses natural botanicals to hydrate, strengthen, and protect hair for sleek, smooth results. Argan and sunflower seed oils condition and strengthen while FluoroSilicones repel hair’s natural oils to maintain lightweight, grease-free shine all day. Number 4™ products are free of sulfates, sodium chloride, and parabens.

How to Use

Distribute one to two pumps through damp hair, then style as usual. For added radiance, apply one pump of product to dry hair. You can also use it to soften cuticles.

Cyclopentasiloxane,C13-14 Isoparaffin,Dimethicone,Dimethiconol,Phenyl Trimethicone,Perfluorononyl Dimethicone,Fragrance (Parfum),Benzyl Salicylate,Butylphenyl Methylpropional,Linalool,Hydroxyisohexyl 3- Cyclohexene Carboxaldehyde,Ethylhexyl Methoxycinnamate,Argania Spinosa Kernel Oil,Helianthus Annuus (Sunflower) Seed Oil,Glycerin,Sodium Ascorbyl Phosphate,Hydrolyzed Soy Protein,Macrocystis Pyrifera Extract,Ribes Grossularia Fruit Extract,Ribes Nigrum (Black Currant) Leaf Extract,Arctium Lappa Root Extract,Avena Sativa (Oat) Kernel Extract,Camellia Sinensis Leaf Extract,Chondrus Crispus (Carrageenan) Extract,Cymbopogon Schoenanthus Extract,Euterpe Oleracea Fruit Extract,Garcinia Mangostana Peel Extract,Hibiscus Sabdariffa Flower Extract,Hydrastis Canadensis (Golden Seal) Root Extract,Ilex Paraguariensis Leaf Extract

More for You!
  • Free returns within 90 days of purchase
  • Extra samples and gifts in the Bonus Shop

Product Reviews & Sample Feedback

19 Reviews
4.6 out of 5 stars
5 Star
4 Star
3 Star
2 Star
1 Star
my profile
people who
Hair type
Hair color
White or gray
17 & under
55 & over

Most Helpful Customer Reviews

Weightless Shine

Love it! I have very very fine, long, color treated hair, so I need a little extra strength/moisture and shine without weighing down my hair any more than usual. I've tried all sorts of serums and glossing creams and stuff in the past with usually average results at best - either I'm not getting the shine results I want or I look like a wet dog, all weighed down with goop. Bought a bottle of this on a whim since I've been such a fan of the other Number 4 products I've sampled, and I'm SO glad I did. This is it.

After a couple of uses, hair is exceptionally shiny and looks healthier than usual. However, my hair is NOT weighed down at all. If anything, it's moving more than usual. And it feels super soft. I'm hoping continued use does improve the health of my hair, but even if not I'd keep using this stuff based on looks alone.

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A little goes a long way!

Nice fragrance and it allowed for a great blowout! My hair felt shiny and healthy without being weighed down. I would definitely consider purchasing this product once my sample runs out.

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soft, silky, weightless - smells amazing

I've been using this religiously for two years now - and have only just finished my second bottle! I have long, fine, straight, color-treated hair and this is a godsend. I use two pumps after I towel dry, and it makes my hair so smooth and silky, protects, the ends, and fights static and frizz. Plus, it smells amazing. My only complaint is the pump. It leaks if you try and travel with it. My solution is to pour a bit in another Birchbox hair oil sample container I received - and good to go!

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great for fine hair

I have super fine hair and winter drives me nuts. This hair oil smells great and did not weigh my hair down at all. It did help with my static when I applied a bit on to my dry hair as well.

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Great product

I have an ombre effect on my hair so my ends tend to look dull unless I frequently treat them with something. I usually do a weekly hair mask which works great but its not something I want to do every day. This product is a great product to put on after I shower and even after I blow dry and straighten. I put a small bit in my palm and it really smooths my ends. It even adds a bit of shine. I would give it a five but the pump is of poor quality. One drop to the floor and it leaks now every time I use it. thats my only complaint.

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Wow- my hair is so soft!

This masque provides weightless shine! My hair is very thick but can get dull and dry, so it's great to have a masque to use every once in a while to revamp my shine. Hair feels so soft and fresh after rinsing! Great product.

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Awesome product!!

This stuff is amazing! I use two squirts after I towel dry my hair, then another 1-2 squirts after blow-drying. It's never heavy, doesn't leave my hair looking greasy and gives my long locks plenty of sheen, silkiness and smoothness. The smell is great too and since it doesn't require a lot to get the shine you want, the bottle will last me a long time. Highly recommended!

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Amazing Oil for Dry & Damaged Hair!

This is a very light oil that doesn't weigh down the body in my hair but makes my hair feel so soft and look so healthy! It also doesn't make my hair look oily the next day. I'm sure this oil would be light enough for those with fine hair, as well! GIVE IT A TRY!

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Brilliant shine

This product is amazing. I love how it makes my hair shine without causing it to be oily. It protects and makes my hair look amazing

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Too Oily

I was excited to try this hair oil, but was disappointed. My hair gets oily easy so I only used a small amount, but it still greased up my hair. It definitely increased shine, but unfortunately gave it that greasy look as well. But as I said, my hair is very prone to becoming oily so this product may work extremely well for others!

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