We give men thicker, stronger hair without drugs or harsh chemicals by combining top ingredients into one serum. Every ingredient is backed by clinical studies and included at the same level for best results.

You’ll be charged $89.97 today and every 3 months. Pause or cancel anytime.

  • Ingredients backed by clinical studies at the dosages shown to work.

    Adenosine (1%) - Proven to restart growth

    Saw Palmetto (5%) - Natural DHT blocker

    Caffeine (0.2%) - Stimulates follicle activity

    Pumpkin Seed (5%) - Restores scalp balance

    Rosemary (0.5%) - Improves blood flow

    Peptide Complex (1%) - Boost density and strength

    Vitamin B3 (2%) - Enhances scalp health

    1. Fill the dropper to the line marked on the glass dropper.

    2. Apply directly to the scalp, focusing on thinning areas.

    3. Gently massage for 30–60 seconds to help absorption.

    4. Let it dry — no need to rinse.

    Tip: Use once a day on a clean, dry scalp for best results. Consistency is key.

  • We believe in our serum and use the most effective ingredients backed by clinical studies.

    If you’re not satisfied within 90 days of consistent use, we’ll refund your first order — guaranteed.

    See full policy

root theory

(150)

Hair Revival Serum

Natural ingredients, powerful results.

  • Boosts circulation and strengthens the scalp environment for growth.

  • Helps block DHT, the hormone that causes hair thinning in men.

  • Clinically shown to improve hair density and activate dormant follicles.

  • Energizes follicles to promote thicker, fuller strands.

  • Boosts circulation and strengthens the scalp environment for growth.

Backed by our 30-day money-back guarantee. We started Root Theory with one clear goal: to take the guesswork out of hair care. Every ingredient was chosen for its proven role in supporting thicker, stronger hair, and together they form a treatment built on science.

Clinically Backed. Proven Results.

Real clinical data behind the ingredients that power Root Theory.

↑ 40%

Increase in hair count after 24 weeks of Pumpkin Seed Oil.
2014 study by Cho et al.

3×

Up to 3x higher thick-hair ratio with topical Adenosine.
2009 study by Tsuboi et al.

↑ 83%

Increase in hair-shaft strength from Caffeine topicals.
2007 study by Fischer et al.

↓ 70%

Reduction in shedding with Saw Palmetto extract.
2023 review by Farris et al.

*Independent studies on individual ingredients. Root Theory mirrors clinically studied concentrations.

root theory

Hair Revival Serum

(150)

We give men thicker, stronger hair without drugs or harsh chemicals by combining top ingredients into one serum. Every ingredient is backed by clinical studies and included at the same level for best results.

  • Ingredients backed by clinical studies at the dosages shown to work.

    Adenosine (1%) - Proven to restart growth

    Saw Palmetto (5%) - Natural DHT blocker

    Caffeine (0.2%) - Stimulates follicle activity

    Pumpkin Seed (5%) - Restores scalp balance

    Rosemary (0.5%) - Improves blood flow

    Peptide Complex (1%) - Boost density and strength

    Vitamin B3 (2%) - Enhances scalp health

  • 1. Fill the dropper to the line marked on the glass dropper.

    2. Apply directly to the scalp, focusing on thinning areas.

    3. Gently massage for 30–60 seconds to help absorption.

    4. Let it dry — no need to rinse.

    Tip: Use once a day on a clean, dry scalp for best results. Consistency is key.

  • We believe in our serum and use the most effective ingredients at transparent, proven levels.

    If you’re not satisfied within 90 days of consistent use, we’ll refund your first order — guaranteed.

    See full policy

  • Ingredients backed by clinical studies at the dosages shown to work.

    Adenosine (1%) - Proven to restart growth

    Saw Palmetto (5%) - Natural DHT blocker

    Caffeine (0.2%) - Stimulates follicle activity

    Pumpkin Seed (5%) - Restores scalp balance

    Rosemary (0.5%) - Improves blood flow

    Peptide Complex (1%) - Boost density and strength

    Vitamin B3 (2%) - Enhances scalp health

  • 1. Fill the dropper to the line marked on the glass dropper.

    2. Apply directly to the scalp, focusing on thinning areas.

    3. Gently massage for 30–60 seconds to help absorption.

    4. Let it dry — no need to rinse.

    Tip: Use once a day on a clean, dry scalp for best results. Consistency is key.

  • We believe in our serum and use the most effective ingredients at transparent, proven levels.

    If you’re not satisfied within 90 days of consistent use, we’ll refund your first order — guaranteed.

    See full policy

Individual results will vary.

When we couldn’t find a drug-free formula that truly worked, we made our own.

Only the most effective, proven ingredients were put in our formula at the dosage shown to work. No shortcuts, no filler. Just results.

  • Men saw up to 40% more hair growth in a 24 week trial.

  • Helps new hairs grow in thicker and stronger

  • Beats Minoxidil in hair growth and user satsifaction

    • Adenosine (1%) — Helps increase the proportion of thicker hairs in androgenetic alopecia. (Watanabe 2015) PubMed+1

    • Saw Palmetto (5%) — Natural DHT-blocking extract linked to improved hair density and reduced hair fall in pattern hair-loss. (Evron 2020) PubMed+1

    • Caffeine (0.2%) — Stimulates hair follicle activity and shows comparability to minoxidil in some studies for growth support. (Dhurat 2017) ishrs-htforum.org+1

    • Pumpkin Seed (5%) — Oral administration linked to around ~40% increase in hair count over 24 weeks in men with mild‐moderate AGA. (Cho 2014) PubMed+1

    • Rosemary (0.5%) — In a 6-month RCT, rosemary oil increased hair count comparable to 2% minoxidil and improved scalp perfusion. (Panahi 2015) PubMed+1

    • Peptide Complex (1%) — Botanical/herbal extract combination (including peptides) showed efficacy comparable to 3% minoxidil in a clinical context for hair density. (Lueangarun 2020) ishrs-htforum.org+1

    • Vitamin B3 / Niacinamide (2%) — Topical nicotinic acid derivatives improved hair fullness in one female pattern-alopecia pilot study. (Draelos 2005)

  • Every active here is dosed at real, research-backed levels — the same concentrations used in clinical studies that showed actual results.

Get My 3-Month Supply

When we couldn’t find a drug-free formula that truly worked, we made our own.

Only the most effective, proven ingredients were put in our formula at the dosage shown to work. No shortcuts, no filler. Just results.

  • Men saw up to 40% more hair growth in a 24 week trial.

  • Helps new hairs grow in thicker and stronger

  • Beats Minoxidil in hair growth and user satsifaction

When we couldn’t find a drug-free formula that truly worked, we made our own.

Only the most effective, proven ingredients were put in our formula at the dosage shown to work. No shortcuts, no filler. Just results.

Beats Minoxidil in hair growth and user satsifaction

Men saw up to 40% more hair growth in a 24 week trial.

Helps new hairs grow in thicker and stronger

Drug-free formula designed to support hair growth and density

  • Adenosine (1%) - Proven to restart growth

    Saw Palmetto (5%) - Natural DHT blocker

    Caffeine (0.2%) - Stimulates follicle activity

    Pumpkin Seed (5%) - Restores scalp balance

    Rosemary (0.5%) - Improves blood flow

    Peptide Complex (1%) - Boost density and strength

    Vitamin B3 (2%) - Enhances scalp health

  • Every active here is dosed at real, research-backed levels — the same concentrations used in clinical studies that showed actual results.

Get My 3-Month Supply

Targets density, strength, and fallout instead of just masking thinning.

Caffeine and Saw Palmetto have matched or beaten Minoxidil

Pumpkin Seed Oil has shown up to 40% more hair growth in 24 weeks.

What to Expect

  1. Week 1–4

    Scalp feels healthier. Oil and irritation begin to settle.

  2. Week 5–8

    Shedding tapers. Roots feel stronger and hair looks steadier.

  3. Week 9–12

    Fullness and texture improve. Hair looks thicker and more resilient.

  4. Ongoing

    Density builds with consistency. Keep going — results compound.

Start your routine

Our Ingredients

We made this for results. Every ingredient has research behind it. We focused on compounds that have been shown to improve hair density, scalp health, and follicle activity.

Rosemary
Natural oil that boosts scalp circulation, found in studies to be comparable to Minoxidil.

Adenosine
Clinically studied molecule that promotes hair thickness and improve the ratio of thicker hairs.

Pumpkin Seed Oil
Supports the scalp environment so that hair can grow under optimal conditions. By helping regulate oil production and inflammation, it supports healthier hair.

Caffeine
Compound that supports hair in its active growth phase. Matches conventional treatments in boosting hair count in several studies.

Saw Palmetto
Helps block DHT on the scalp, the hormone that shrinks hair follicles over time.

Vitamin B3 + Peptide Complex
Enhances hair fiber quality and promotes strand density. Provides visibly fuller appearance.

Our Ingredients

We made this for results. Every ingredient has research behind it. We focused on compounds that have been shown to improve hair density, scalp health, and follicle activity.

Rosemary
Natural oil that boosts scalp circulation, found in studies to be comparable to Minoxidil.

Adenosine
Clinically studied molecule that promotes hair thickness and improve the ratio of thicker hairs.

Pumpkin Seed Oil
Creates a healthy scalp environment for optimal growth by balancing oils and reducing inflammation.

Caffeine
Compound that supports hair in its active growth phase. Matches conventional treatments in boosting hair count in several studies.

Saw Palmetto
Helps block DHT on the scalp, the hormone that shrinks hair follicles over time.

Vitamin B3 + Peptide Complex
Enhances hair fiber quality and promotes strand density. Provides visibly fuller appearance.

How to apply

  • A person holding a dropper with clear liquid, applying it to their scalp, with fingers in their hair.

    1. drop it on

    Once a day (dosage marked on the dropper) drop directly onto the scalp in the areas you are targeting.

  • Close-up of a person's forehead and dark hair being touched by their hand, with a gray background.

    2. Rub it in

    Gently massage with your fingers.

  • A black round analog clock with a digital display, showing the time as 11:29, placed on a white surface next to a gray cushion and a wooden object.

    3. Wait for a little.

    Let it soak into the scalp before the next step of your routine, wheteher thats going to sleep or blow drying and stying your hair.

Frequently Asked Questions

We get it—losing hair can mess with your confidence, your mirror routine, and your sanity. Luckily, we’ve spent way too much time studying scalp science so you don’t have to. Here’s everything you might be wondering.

  • Our serum helps re-activate dormant follicles by improving scalp circulation and supporting natural growth factors. Each ingredient—like caffeine, adenosine, and peptides—was chosen based on real clinical studies showing they can thicken existing hair and extend the growth phase of your hair cycle.

  • Most users notice less shedding within 3–4 weeks, with visible growth and density changes appearing around 8–12 weeks of consistent use. Hair growth is gradual—it’s about patience and consistency, not overnight miracles.

  • Yes. The formula is drug-free, non-greasy, and safe for sensitive scalps. It’s designed for everyday use and won’t interfere with other topical products or styling routines.

  • Absolutely. Our serum is topical and complementary. It can enhance results by targeting scalp health and follicle stimulation while minimizing irritation.

  • Nope. The lightweight, fast-absorbing texture disappears after letting it absorb. You can apply it before bed or after a shower—no residue, no buildup, no weird smell.

  • Think of it like skincare for your scalp. Consistent use keeps follicles healthy and active. Once you reach your desired fullness, you can reduce to maintenance use (2–3 times per week) to preserve results.

  • The formula works for both men and women, but it’s optimized for male-pattern hair loss—especially receding hairlines and thinning at the crown.

  • Yes! The serum is color-safe and sulfate-free—you can use it on dyed, bleached, or chemically treated hair without issues.

Reviews as clean as our formula