DALLAS Biotin Thickening Shampoo
DALLAS

Biotin Thickening Shampoo

This thickening shampoo adds vitality to fine, flat hair while nourishing and strengthening from root to tip.

High-performance

Award-winning

Vegan

Cruelty-free

How to use

Step 1
Apply to roots and work through ends.
Step 2
Rinse.
Step 3
Follow with DALLAS Conditioner.

GET THE EXPERT LOOK

Shop the Look

Step 1

DALLAS Biotin Thickening Shampoo
DALLAS
Biotin Thickening Shampoo
NOURISHMENT•STRENGTH•VOLUME
$38
For big, beautiful, bouncy hair, use DALLAS. This thickening shampoo adds vitality to fine, flat hair while nourishing and strengthening from root to tip.

Step 2

DALLAS Biotin Thickening Conditioner
DALLAS
Biotin Thickening Conditioner
NOURISHMENT•STRENGTH•VOLUME
$38
The final step for hair as big as Texas. DALLAS Biotin Thickening Conditioner revitalizes hair with lightweight hydration. Infused with Biotin for prolonged strength and enhanced shine.

Step 3

RODEO STAR Thickening Style Foam
RODEO STAR
Thickening Style Foam
VOLUME•THICKENING•HOLD
$38
Saddle up with RODEO STAR Thickening Style Foam to instantly add density and lift to your hair. A natural-feeling and non-sticky formula that adds volume.

IN THE WILD

WHAT PEOPLE ARE SAYING

4.8
Rated 4.8 out of 5 stars
Based on 435 reviews
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435 reviews
  • Elizabeth B.
    Verified Buyer
    Hair Density Medium
    What is your main hair goal? Volume + Texture
    November 12, 2026
    Hair Density Medium
    What is your main hair goal? Volume + Texture
    Reviewing
    DALLAS Biotin Thickening Shampoo Retail Liter
    Rated 5 out of 5 stars
    Love this product!

    I'm excited that R+Co is carrying a line of shampoo and conditioner for those of us with thinning hair. I've used it a few times and it's definitely a nice shampoo. My hair feels great after drying. Looking healthier already.

    Was this helpful?
  • Kristiina H.
    Verified Buyer
    Hair Type Straight
    Hair Density Fine
    What is your main hair goal? Volume + Texture
    November 10, 2026
    Hair Type Straight
    Hair Density Fine
    What is your main hair goal? Volume + Texture
    Reviewing
    DALLAS Biotin Thickening Shampoo
    Rated 5 out of 5 stars
    Best shampoo for adding volume

    Having tried volume shampoos in the past, I didn’t really expect much, but I was pleasantly surprised to find that it really does add volume to my very fine hair!

    Was this helpful?
  • Nancy R.
    Verified Buyer
    Hair Type Wavy
    Hair Density Fine
    What is your main hair goal? Volume + Texture
    November 5, 2026
    Hair Type Wavy
    Hair Density Fine
    What is your main hair goal? Volume + Texture
    Reviewing
    DALLAS Biotin Thickening Shampoo
    Rated 5 out of 5 stars
    Great Shampoo

    I love the shampoo and it is so concentrated. I had to get used to using less.

    Was this helpful?
  • Adrianna C.
    Verified Buyer
    Hair Type Straight
    Hair Density Fine
    What is your main hair goal? Volume + Texture
    October 26, 2026
    Hair Type Straight
    Hair Density Fine
    What is your main hair goal? Volume + Texture
    Reviewing
    DALLAS Biotin Thickening Shampoo Mini
    Rated 5 out of 5 stars
    Love!

    Love so much that I am buying it in full size!

    Was this helpful?
  • Mary L.
    Verified Buyer
    Hair Type Straight
    Hair Density Fine
    What is your main hair goal? Volume + Texture
    October 20, 2026
    Hair Type Straight
    Hair Density Fine
    What is your main hair goal? Volume + Texture
    Reviewing
    DALLAS Biotin Thickening Shampoo
    Rated 5 out of 5 stars
    Excellent!! daily use thickening shampoo

    Love this shampoo for daily thickening and volume without any drying effects.

    Was this helpful?