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Here's Your Perfect Match for Fuller & Thicker Hair!

92% of women with your profile saw visibly thicker looking hair in just 60 days.
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Here's Your Perfect Match for Fuller & Thicker Hair!

92% of women with your profile saw visibly thicker looking hair in just 60 days.
Promotes fuller-looking hair
Reduces the appearance of shedding and fallout
Shop Now
Our results may vary, but most women see changes within 90 days.
See the product
Clinically Proven for Fuller, Stronger Hair in just 90 Days
97%
Noticed stronger, more resilient hair with less brittleness.*
94%
Reported a visible reduction in hair loss.*
97%
Experienced support for new hair growth, resulting in fuller, thicker hair.*
See the product
*Based on a clinical study with 33 participants over 90 days.

Real Customers Results

Combining the power of science and nature to deliver both quick and visible results with a tested formula, perfect for every hair type:
Promotes a fuller-looking hair
Reduces the look of shedding andfallout

Provides a thickening-like effect

Thousands of Women Reclaimed Their Confidence & Fell Back in Love With Their Hair

Find out how women everywhere are finally reducing visible thinning, restoring strength, and feeling confident again—without harsh treatments or complicated routines.
Zoe Gresham
Verified Customer
Less Hair on My Brush—Finally!

I’ve struggled for years with shedding and dryness, especially around the crown. After a few weeks, I noticed way less hair on my brush and my scalp doesn’t feel so irritated. My hair looks fuller, especially at the top, and has more bounce—it actually feels alive again.

Grace Delaney
Verified Customer
Thicker Hair That Actually Feels Stronger

I’ve tried so many serums over the years with no real results. This one is different—my scalp feels soothed, my hair feels stronger, and I’m seeing less breakage when I wash it. Even my hairdresser noticed it looked thicker last time I went in.

Zoe Gresham
Verified Customer
Healthier Scalp, Fuller Hair

My scalp feels so much healthier, and my hair looks noticeably thicker. It’s lightweight, non-greasy, and works wonders on my fine hair. I can’t believe the difference it’s made!

Rosemarie S.
Verified Customer
Thicker Hair in Just a Few Weeks

I’ve been using this hair serum for about three weeks, and the results are amazing. My hair looks visibly fuller and thicker. I’ve even noticed that my scalp isn’t as visible anymore. This serum has become a staple in my routine!

The Proven Solution for the Look of Thicker, Fuller, Healthier Hair

Thicker, fuller hair that turns heads
Proven to increase hair density by up to 9.1%, helping you achieve a fuller, healthier look with continued use.
Say goodbye to bald spots and a visible scalp
Formulated with science-backed, non-toxic ingredients that nourish and revitalize your scalp, creating the ideal environment for hair growth.
Rebalance your scalp health for lasting results
Repairs damage caused by harsh products, hard water, and hormonal changes—creating the ideal environment for hair to thrive.
Premium, clinically-tested results—without the premium price tag
Affordable hair restoration backed by science, made for real women dealing with hair loss today.
Works for all hair types—even severely thinning hair
Whether you’re experiencing hormonal hair loss, thinning from stress, or damage from styling, our serum works for you.
Claim Your Offer Now
Claim a FREE Scalp Massager (Worth $39.99) With Your Order Today!

The key behind the solution: Science-Backed Ingredients

Doctor-Formulated powerful blend of clean, non-toxic and effective ingredients, each chosen for their ability to promote healthier and thicker-looking hair.

Peptides

Stimulate hair growth and strengthen strands from root to tip.

Red Clover Flower Extract

Packed with bioactives to visibly enhance thickness and density.

Pea Sprout Extract

Loaded with phytonutrients to promote rapid growth and fullness.

Centella Asiatica(Gotu Kola)

Soothes the scalp and boosts overall hair health.

Full Ingredients' list

Water, Pentylene Glycol, Propanediol, Gluconodeltalactone, Niacinamide, Sodium Citrate, Acetyl Tetrapeptide-3, Trifolium Pratense (Clover) Flower Extract, Pisum Sativum (Pea) Sprout Extract, Cucurbita Pepo (Pumpkin) Seed Extract, Centella Asiatica (Gotu Kola) Extract, Panax Ginseng Root Extract, Macrocystis Pyrifera (Kelp) Extract, Glycerin, Butylene Glycol, Dextran, Sodium Benzoate, Citric Acid.

We’re Serious About Quality

The Spa Dr.'s Hair Serum!

Clinically tested, Doctor-Formulated Serum with a powerful blend of clean, Non-Toxic ingredients proven to strengthen and revitalize Hair!
Over 2,000 purchases last month
-50%
$24.50
$49.00
($0.49 / Milliliter)
Free Gifts when you shop Today
FREE
Scalp massager
$39.99 value
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Free US shipping & Free gift
30 day money back guarantee
Pause/cancel anytime
Free returns, without questions
Buy Once - $66 + $6.95 shipping
We recommend a subscription as most results tend to come after 2 months of daily use!

The Spa Dr.'s Hair Serum!

Clinically tested, Doctor-Formulated Serum with a powerful blend of clean, Non-Toxic ingredients proven to strengthen and revitalize Hair!
Free Gifts when you shop Today
FREE
Scalp massager
$39.99 value
Shop Now
Free US shipping & Free gift
30 day money back guarantee
Pause/cancel anytime
Free returns, without questions
Buy Once - $66 + $6,95 shipping
We recommend a subscription as most results tend to come after 2 months of daily use!
Subscribe and Save
Over 2,000 purchases last month
-50%
$24.50
($0.49 / Milliliter)
Original Price: $49.00
Save 50% on recurring deliveries of this product  
  • No subscription fees
  • Cancel anytime*
Refill ships in 30 days
Adjust shipments or cancel anytime*
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30-Day Money-Back Guarantee
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BUY NOW - 50% OFF
Recurring deliveries sold by The Spa Dr.

How to use it

3 Easy Steps to Fuller, Stronger Hair

Apply 1 to 2 dropperfuls directly to your scalp, sectioning your hair with the dropper tip. Use enough serum to lightly cover the areas of concern. Massage with your fingertips or scalp massager.
Use daily for best results.
Track your progress with photos and celebrate thicker, healthier hair—most users see a transformation in 90 days!

Raving Reviews

4.6/5
2,378+ Reviews
Elara Winslow
Verified Customer
February 20, 2025
A Go-To for Postpartum Hair andItchy Scalp Relief
Healthier Scalp and Less Shedding with This Serum

This serum has done wonders for my scalp's health! It has significantly reduced signs of shedding and fallout. The refreshing scent is a nice touch

I'm a big fan of Dr. Trevor Cates and havefollowed her for years. I tried this serum forpostpartum hair loss and my dry, itchyscalp. I use it daily with a dropper andmassage it in. When my scalp feels good, Itake a break, but I always come back to itwhen the itchiness returns.

Daphne Sinclair
Verified Customer
January 15, 2025
Noticeable Results!
Noticeable Results!

I've used this for 3 months, and the tingling is great. My scalp doesn't itch anymore, and my hair looks thicker. Definitely recommend it!

I've used this for 3 months, and the tingling is great. My scalp doesn't itch anymore, and my hair looks thicker. Definitely recommend it!

Sarah Redmond
Verified Customer
January 11, 2025
Affordable Quality, Incredible Results
Affordable Quality, Incredible Results

I’ve tried so many expensive products, but this serum outperforms them all. It’s affordable, high-quality, and has given me the fuller, thicker hair I’ve always wanted. My scalp also looks so much better now. I highly recommend it!

I’ve tried so many expensive products, but this serum outperforms them all. It’s affordable, high-quality, and has given me the fuller, thicker hair I’ve always wanted. My scalp also looks so much better now. I highly recommend it!

Isabella White
Verified Customer
December 8, 2024
Thicker, Longer Hair After Just a Few Uses
Thicker, Longer Hair After Just a Few Uses

This hair serum is amazing! After hearing so many recommendations, I tried it and noticed a big difference. My hair, which struggled to grow due to heat and products, is now thicker and longer. I use it every other day. Highly recommend giving it a try!

This hair serum is amazing! After hearing so many recommendations, I tried it and noticed a big difference. My hair, which struggled to grow due to heat and products, is now thicker and longer. I use it every other day. Highly recommend giving it a try!

Zoe Gresham
Verified Customer
August 7, 2024
Healthier Scalp, Fuller Hair
Healthier Scalp, Fuller Hair

y scalp feels so much healthier, and my hair looks noticeably thicker. It’s lightweight, non-greasy, and works wonders on my fine hair. I can’t believe the difference it’s made!

My scalp feels so much healthier, and my hair looks noticeably thicker. It’s lightweight, non-greasy, and works wonders on my fine hair. I can’t believe the difference it’s made!

Tamsin Lovell
Verified Customer
August 5, 2024
Too Early to Tell, But Loving the way it feels
Too Early to Tell, But Loving the way it feels

I have thinning hair, so I decided to try this. It’s too soon to tell if it’s helping with growth, but it smells nice and gives my scalp a pleasant tingle. I’m going to keep using it.

I have thinning hair, so I decided to try this. It’s too soon to tell if it’s helping with growth, but it smells nice and gives my scalp a pleasant tingle. I’m going to keep using it.

Emma Brooks
Verified Customer
August 3, 2024
Healthier Scalp and Less Shedding with This Serum
Healthier Scalp and Less Shedding with This Serum

This serum has done wonders for my scalp's health! It has significantly reduced signs of shedding and fallout. The refreshing scent is a nice touch

This serum has done wonders for my scalp's health! It has significantly reduced signs of shedding and fallout. The refreshing scent is a nice touch

Grace Delaney
Verified Customer
August 2, 2024
Thicker Hair in Just a Few Weeks
Thicker Hair in Just a Few Weeks

I’ve been using this hair serum for about three weeks, and the results are amazing. My hair looks visibly fuller and thicker. I’ve even noticed that my scalp isn’t as visible anymore. This serum has become a staple in my routine!

I’ve been using this hair serum for about three weeks, and the results are amazing. My hair looks visibly fuller and thicker. I’ve even noticed that my scalp isn’t as visible anymore. This serum has become a staple in my routine!

Lauren Bennett
Verified Customer
August 12, 2024
Effective for Postpartum Hair Loss
Effective for Postpartum Hair Loss

Hoping this helps with postpartum hair loss. It's easy to apply, but it can leave my hair a bit oily, so I usually use it when I'm staying at home.

Hoping this helps with postpartum hair loss. It's easy to apply, but it can leave my hair a bit oily, so I usually use it when I'm staying at home.

Vicki M.
October 23, 2024
Jill S.
November 7, 2024
Angela B.
December 1, 2024

Formulated by the renownedDr. Cates

Backed by Dr. Trevor Cates

Her groundbreaking discoveries in the clean beauty industry led her to be invited to the acclaimed The Doctors show, write 2 bestsellers, being featured in over 250 podcasts and host her own TV Show.
“We developed perfectly balanced formulas containing my favorite clean, safe, organic & effective ingredients. It is the only product I know that uses them in the right dosage and without being combined with potentially harmful chemicals.”

Satisfaction Guaranteed

Try today risk-FREE!
Love it or your money back!

If you’re not completely thrilled with your results, or if your family and friends aren’t telling you how amazing your hair looks… You will get a full refund within the first 30 days after ordering The Spa Dr. Hair Serum—no questions asked.

Frequently Asked Questions

What is the full ingredient list?

Water, Pentylene Glycol, Propanediol, Gluconodelta- lactone, Niacinamide, Sodium Citrate, Acetyl Tetrapeptide-3, Trifolium Pratense (Clover) Flower Extract, Pisum Sativum (Pea) Sprout Extract, Cucurbita Pepo (Pumpkin) Seed Extract, Centella Asiatica (Gotu Kola) Extract, Panax Ginseng Root Extract, Macrocystis Pyrifera (Kelp) Extract, Glycerin, Butylene Glycol, Dextran, Sodium Benzoate, Citric Acid.

How should I use this Hair Serum?

For optimal results, apply the Hair Serum daily. Dr. Cates recommends using it once in the morning and once in the evening. Simply part your hair into sections, apply a few drops directly onto the scalp, and gently massage with your fingertips to support better absorption. It takes just a couple of minutes to complete.

Is this Hair Serum fragrance-free?

Yes, our Hair Serum is completely fragrance-free. We've carefully crafted this formula to focus on supporting the appearance of you hair and scalp without the potential irritation that fragrances can cause. Enjoy a clean, natural experience that prioritizes your hair and scalp’s comfort.

Can I use this Hair Serum if I have sensitive skin?

Absolutely. Dr. Cates has designed this Hair Serum to be gentle yet effective for all scalp types, including sensitive skin. However, if you’re concerned, we recommend performing a patch test on the inside of your elbow to ensure compatibility with your skin.

How long will it take to see results?

Results may vary depending on the individual, but many of our users notice a reduction in the appearance of hair shedding and a healthier-looking scalp within the first few weeks. For best results, consistent use over 4-8 weeks is recommended.

Is this product safe for color-treated hair?

Yes, our Hair Serum is safe for color-treated hair. Its gentle formula is designed to nourish and support your hair's appearance without stripping or fading color.

Is the Hair Serum gluten and soy-free?

Yes, our Hair Serum is both gluten-free and soy-free, making it suitable for those with sensitivities to these ingredients.

What is the shelf life of the Hair Serum?

Our Hair Serum has a shelf life of 2 years when unopened. Once opened, it should be used within 12 months to ensure maximum efficacy and freshness.

Do you offer refunds?

Yes, we stand by the quality of our products. If you're not completely satisfied with your purchase, you can request a refund within 30 days of the ship date. Please contact our customer service team for assistance.

Will the Hair Serum leave my hair greasy?

No, our Hair Serum is formulated to be lightweight and non-greasy, ensuring your hair feels natural and clean after application.