Editor's TipEditor's Tip

For best (ie: biggest) results, follow with Number 4 Volumizing Condition, which adds both body and shine.

Number 4 Hair Care

Birchbox Breakdown

This sulfate-free shampoo proves that style and substance aren't mutually exclusive. The sleek packaging and fresh scent are a nod to Parisian flair, while the scientific formula is designed to turn fine, flat strands into rich, full-bodied hair. The brand's four signature Liquid Complexes—blends of natural extracts—work to protect, strengthen, and purify strands without weighing them down.

How to Use

Dispense into hands and rub together to form a lather before massaging into wet hair. Lather and rinse, then follow with Volumizing Condition.

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

Product Reviews & Sample Feedback

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Most Helpful Customer Reviews

Volumizes thick hair without making it greasy

I appreciated that even though I have to use a lot of shampoo on my thick hair, this product gave my hair great volume without making it greasy--ideal for my hair type!

5
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Good stuff

I felt that this shampoo did a good job of putting body into my limp fine hair. It definitely teased better and had better texture than usual. However, I felt my hair was a little dry and duller than usual.

4
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Great for Thin Hair

Last month I tried the Number 4 clarifying shampoo and thought it was too thick for my hair. I liked the volumizing shampoo much better! It lathered up well and didn't feel heavy on my fine hair.

4
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LOVE no.4

My shampoo loyalties are in a constant tug of war between No.4 and Davines thanks to Birchbox. I love the scent of this product and a little bit went a long way. Not sure if it made much difference in terms of making my very fine hair more voluminous, but it certainly didn't hurt. Would consider buying this.

5
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Smells Amazing

Product is a great shampoo that smells wonderful. Really cleanses hair well. Lathers great. Just can't get over how good it smells!

5
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Added volume to my fine hair

Added volume without drying out my hair and scalp. My hair even had more volume after sleeping on it. Plus, a little goes a long way.

5
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Nice Shampoo

I like this quite a bit, but I already have a shampoo that I love.

5
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Yes Yes Yes!

Love this shampoo. It lathers beautifully and really adds volume. My second day hair was even poofy (in a good way)! I will buy the full size.

5
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Made my hair dry

The smell of this product is wonderful! When I went to use it the shampoo was very thick and sticky like. After I dried my hair, my hair was so much more dry and felt like my hair would break off. Maybe I used too much? I'll have to try it out again to see again

3
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Good

While I do think this brand is good, in pretty sure I've gotten a different version of their shampoos and conditioners in every single box lately

3
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