• ACTIIV Thickening Hair Serum Water-Based 1.8 oz plant-based hair and scalp serum for thicker, fuller-looking hair
  • key benefits for actiiv water-based thickening hair serum
  • Instructions on how to use actiiv water-based thickening hair serum with a bottle, application on hair, and a smiling person.
  • Bottle of actiiv water-based thickening hair serum with product feature icons on a beige background
  • Before and after comparison of a person's hairline using a water-based hair serum.
  • Three key ingredients for water-based thickening hair serum displayed with coffee beans, red clover flowers, and green tea leaves.

Thickening Hair Serum - Water Based

ACTIIV Thickening Hair Serum transforms your daily routine into a targeted scalp care ritual — designed to strengthen follicles, optimize scalp, and improve hair density.
Its clean, water-based formula absorbs instantly, delivering lightweight nourishment and noticeable results with every use. Ideal for straight to wavy hair or those with extensions.

Size:

90 Day Guarantee

  • Thickens and strengthens hair with a lightweight, fast-absorbing water-based formula
  • Targets areas of concern to support denser, fuller-looking hair over time
  • Improves strand strength and resilience, reducing breakage and shedding

Step 1 — Start with wet or dry hair

Step 2 — Apply Serum Directly to Scalp
Using the precision dropper, apply 1 full dropper directly onto areas of focus — typically along the hairline, crown, or areas experiencing thinning.
Part the hair to expose the scalp and distribute evenly with fingertips.

Step 3 — Massage to Activate
Massage gently for 30–60 seconds to help evenly spread the serum.
Do not rinse — this leave-in formula is designed for full absorption.

Step 4 — Style as Usual
Allow a few minutes for the serum to absorb fully before styling. For best results, use daily.

Water (Aqua), Aloe Barbadensis Leaf Juice, Glycerin, Trifolium Pratense Flower Extract, Pisum Sativum (Pea) Sprout Extract, Epilobium Fleischeri Extract, Caffeine, Hydrolyzed Quinoa, Hydrolyzed Adansonia Digitata Seed Extract, Camellia Sinensis Leaf Extract, Serenoa Serrulata Fruit Extract, Hippophae Rhamnoides Fruit Extract, Curcuma Longa Root Extract, Genista Tinctoria Flower/Leaf/Stem Extract, Cucurbita Pepo Seed Extract, Rosmarinus Officinalis Leaf Extract, Polysorbate 20, Isomalt, Xanthan Gum, Fragrance (*)Gluconolactone, Sodium Benzoate, Potassium Sorbate, Citric Acid.

Individuals noticing early signs of thinning or shedding who want a clean, lightweight serum to support thicker, fuller-looking hair.

Top: Mint, Orange, Plum, Bergamot
Middle: Rose, Mate, Violet Nutmeg
Bottom: Vanilla, Oakmoss, Sandalwood, Amber

Plant-Based, Scalp-Focused Ingredients

Caffeine ingredient icon from ACTIIV hair care, supporting invigorated scalp and stronger hair roots. Caffeine ingredient icon from ACTIIV hair care, supporting invigorated scalp and stronger hair roots.

Caffeine

Helps to invigorate the scalp, support healthy microcirculation, deliver essential nutrients, and promote the appearance of stronger hair.

Red Clover botanical ingredient icon in ACTIIV hair care, used for antioxidant support and scalp nourishment. Red Clover botanical ingredient icon in ACTIIV hair care, used for antioxidant support and scalp nourishment.

Red Clover

Rich in natural compounds, it helps maintain a clean-feeling, balanced scalp for healthier-looking hair.

Green tea botanical ingredient icon featured in ACTIIV hair care for antioxidant and scalp-refreshing benefits. Green tea botanical ingredient icon featured in ACTIIV hair care for antioxidant and scalp-refreshing benefits.

Green Tea

Rich in polyphenols and antioxidants, it helps protect the scalp from external stressors.

Overall rating: 4.576923 / 5 from 52 reviews.

AI Generated Review Summary

Actiiv Thickening Hair Serum is designed to enhance the appearance of thicker, fuller hair. Users report varied results, with some noticing fuller and healthier-looking hair, while others see little change. The water-based formula is generally well-received for its non-greasy texture and pleasant scent. Ideal for those with fine, thin hair aiming to reduce breakage and shedding.

Summary topics

  • Hair Appearance: 49%
  • Product Scent: 14%
  • Visible Results: 14%
  • Product Formula: 11%

Review topics: ["results","feeling","texture","scent","formula","packaging","hair","difference","oil","scalp","bottle","serum","growth","change"].

Review highlights

  • "And my hair feels so much fuller." — Leah U.
  • "The ingredients are decent with ingredients such as Aloe and Pumpkin seed - the scent is subtle and clean." — JustlilOme
  • "My hair is growing super fast." — Jewells P.

Reviews

Once I receive the product,

"Once I receive the product, which I was very excited to get, it was surprisingly nice. I chose water versus oil because of the products I use to set my hair. The smell was a little strong initially. I was afraid it would trigger a migraine, but I got use to it after a bit and couldn’t smell it. I can’t really tell at this point if it’s working, but I’m hopeful. It is not irritating to my scalp and it has a nice cool feel. I set my self on auto order to receive more. I’m excited as a hair loss hopeful."

— Yolanda B. (5/5)

Does not absorb into the scalp

"Only been using for 6 week so no visible growth as yet. Will continue using with hope it will work."

— Debra S. (3/5)

Great product!!!!

"I have been using this for 4 months now and have seen a noticeable difference in the thickness of my hair!!! Love it"

— Roberta S. (5/5)

good hair serum

"The formula is lightweight and isn't greasy. A little goes a long way, so I can see this lasting a long time, which is good at this price point. My hair looks a little fuller and thicker after application. It seems like a very good quality product, and I'm happy with it."

— Shorty (5/5)

Works Amazing!!

"I love this product. I see tons of tiny baby hairs growing. It doesn’t leave my hair oily and I am so glad about that. My hairdresser even noticed my hair is thicker and fuller. I will always have a spare bottle so I don’t run out."

— Karen A. (5/5)

Non-oily, full-disclosure ingredients for a peace of mind scalp and hair treatment

"I find it interesting that this hair-thickening serum actually doesn't promise ""hair thickening"". The phrasing is actually ""Appearance of Thicker, Fuller-Looking Hair"". Maybe it's just splitting hair(joke unintentional), but that distinction makes a world of difference in their claim versus expectation and verifiability, one where it's not even necessary to measure the thickness of individual hair, because it only needs to ""appear"" as such. And that is supported by a full disclosure of ingredients, both in product photo and on the bottle label. No oils, be it plant or synthetic, no chemicals. Well-known plant extracts, from aloe, pea sprout, flower, fruits, etc. No surprises, but all good. A light to medium floral fragrance, so it can be noticeable by others if you suddenly start using it. Once a day, after shower or something as it's meant to stay on the scalp instead of being rinsed after. Honestly, after weeks of using it, I don't particularly think my hair is thicker. I'm not going to take hair samples and compare thickness measurement, but rather it's a matter of ""Does my hair appear thicker?"" I dare say it does appear better, and feel better. The regular massaging involved in the applying of this serum may have a part in that result. The tougher question, Is it worth the money? I can't say for sure. It's not going to make magic happen, but it maybe worth it over the course of months and years of regular application with a massage, allowing better scalp nourishment and circulation."

— M S. (4/5)

Lightweight Hair Serum

"This hair serum is easy to use, has a pleasant scent, and doesn't leave your hair looking really greasy or oily afterwards. The bottom of the dropper is curved, which I find makes it easier to use and reduces the chances of dripping. As to how well it works, it's hard to say. I haven't noticed any big differences; however, I read online that results for these types of things could take months."

— Raymond W. (4/5)

Scalp is showing…

"I srarted noticing my thinning hair after a TIA & stent placement-age 70. Used my husband’s product for a while -recommended by our stylist."

— SHARON O. (5/5)

Still trying this out

"I got this product a couple months ago but I’m still testing out the results. For now, it works great."

— Michelle (5/5)

"I like the scent and the lightness of the oil."

— Tonia (5/5)

Q&A

Your Questions Answered, Before You Buy

A lightweight daily leave-in scalp serum that delivers plant thickening actives between washes. Designed to complement the Recover system — keeping active ingredients on the scalp on non-wash days.

Water-Based: ideal for fine, straight, or low-porosity hair.

Oil-Based: ideal for textured, coily, or high-porosity hair. Both deliver the same thickening actives — choose by hair type.

No. The water-based formula absorbs quickly and leaves zero residue—perfect for those who dislike the feel of oils.

Most users notice less shedding within 6–8 weeks and visibly fuller-looking hair within 3–6 months. Continued daily use maintains and enhances results.

Yes. Apply the serum first, let it absorb, then use your styling or heat-protective products as usual. It’s color-safe and scalp-safe.

Absolutely. Use Recover or Renew to cleanse and prepare the scalp, then apply the serum daily between washes to keep scalp nourishment active.

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