I Bought & Tested the Best-Selling Hair Growth Serums. Here's Why RootQuill is #1:
Written by Dr. Rachel Hartman
That morning kicked off a three-month obsession. Every Sunday I photographed my part line under the same bathroom light, and I started counting strands in my brush like a nervous accountant. Eleven products later, I had a drawer full of bottles and nothing measurable to show for it.
A heavy rosemary-and-castor oil left my roots flat and greasy by noon. A perfumed botanical serum made my scalp itch within four days. A pricey blend stung so badly I quit after a week, and the biotin gummies I swallowed for two months changed nothing I could see.
As someone who has tested more than 40 hair and scalp care products over seven years, I knew I was judging on hope instead of data. So I narrowed the field to Best 5 America and tested them properly. RootQuill reached me through my inbox, recommended by several readers, but it was sold out when I first tried to order, and I waited two weeks before I could place mine.
Here's what I found.
My Test Results
Our team ran an 8-week side-by-side panel with 20 volunteers aged 28 to 61, four per serum, all dealing with self-reported thinning or shedding. Everyone applied their assigned serum once daily as directed. I collected weekly part-line photos in identical lighting, had each volunteer count shed strands on their brush three mornings a week, and I tested the eventual top pick myself for the full eight weeks.
Each serum was scored on four criteria: Visible Results, Ingredient Quality, Ease of Use and Scalp Safety. We added a weekly comfort diary and an end-of-test satisfaction survey, then compared every serum head to head instead of against its own marketing claims.
The headline number: RootQuill reduced average brush shedding from about 65 strands to roughly 40 by week 8, close to a 40% drop. Rival serums landed between under 10% and about 22%. First visible changes arrived around week 5, and by week 8 all four panelists in that group saw a fuller-looking part line.
The secondary wins were just as telling. Scalps felt calmer and less tight within two weeks, and shine and softness were obvious in photos by week 6. The formula also held up over extended use, staying consistent from the first application to the last with no clumping or separation.
My only real frustration was logistical. It sells out, and I waited two weeks to order mine. Like any serum, it isn't an overnight fix, so expect to give it five to eight weeks. Neither point is a deal-breaker, and the second applies to every product in this guide.
The Results:
Backed by weeks of data and daily use, RootQuill is the hair growth serum I'd recommend to anyone serious about fuller-looking hair.
Value
Since adding this serum to my routine, I've stopped cycling through a new bottle, oil or gummy every few weeks, and I've stopped spending mornings layering products that never quite worked. The real payoff was time reclaimed and a bathroom drawer that finally stopped growing.
Consider what doing nothing costs. Another year of watching the drain, hiding your part and buying cheap alternatives that sting, smell or simply fail adds up in confidence and in wasted bottles. Temporary fixes are the expensive choice because they delay the one thing that works.
On durability, the bottle held up through eight weeks of daily use without leaking, and the formula stayed consistent to the end. A 1-year warranty is far longer than the short return windows most serums offer, which tells you the brand stands behind its product. For something you'll use every day, that's a smart long-term decision.
Fuller Hair, Easier Mornings
My routine is simple now: after the shower, a quick application, then straight to styling. No waiting, no sticky roots, and no perfume competing with my shampoo. The bigger change is confidence, because I've stopped doing the quiet tilt-and-check in every mirror I pass.
The benefits stretch beyond my own bathroom. It suits all hair types, from dry to oily to sensitive scalps, and the fragrance-free, vegan formula appeals to anyone picky about what touches their skin. Busy parents, frequent stylers and people tired of heavy oils will appreciate it. One caution: sudden or patchy loss deserves a doctor's visit first.
Customer Reviews
Postpartum shedding hit me hard around month three and I honestly cried over the shower drain. After 7 weeks of using this, my brush catches about half as much hair and I can see tiny new hairs along my hairline. It soaks in while the coffee brews, which is all the time I have with a newborn.
At 56 I had accepted that my part was just going to keep widening, and every heavy oil I tried made my hair look limp. A friend pushed me to try this one. Around week 6 I noticed my part looked narrower in the same bathroom light, and my scalp, which reacts to almost everything, has had zero problems. It isn't instant, so be patient, but I'm really glad I stuck with it.
I'm a stylist and my own hair takes heat all day. No sting, no residue, and it feels softer. Two of my clients have asked what I'm using.
Frequently Asked Questions
In our panel, the first visible changes appeared around week 5, with clearer results by week 8. Hair grows in cycles, so no serum can deliver real change in a few days.
Treat anything that promises overnight results as a red flag.
Most are formulated for broad use, but texture and scalp type still matter. RootQuill is lightweight enough for dry, oily and sensitive scalps, and it absorbs without weighing hair down.
It depends on the formula. Heavy oils and thick textures left roots flat by midday, which was the most common complaint in our panel.
Lightweight, fast-absorbing serums avoid this, and our top pick left no visible residue on any volunteer.
Yes, especially formulas with strong fragrance, alcohol or concentrated essential oils. Look for fragrance-free options and patch test behind your ear first.
Nobody in our top pick's group reported stinging or itching, but individual reactions can still vary.
Most serums are designed for once-daily use on a clean scalp, but always follow the label. Consistency matters more than quantity, so applying extra won't speed up results.
Choose something quick enough that you'll actually use it every day.
If you notice sudden shedding, bald patches or a painful, inflamed scalp, see a doctor first. Hair loss can have medical causes such as thyroid problems, nutritional deficiencies or hormonal changes that a topical product can't fix.
A serum works best as support for ordinary thinning and shedding.
Our top pick is backed by a 1-year warranty and ships free, which is far more generous than the short return windows most serums offer. Delivery is quick once your order is placed.
Demand regularly outpaces supply, and I waited two weeks before I could place my own order.
If RootQuill is in stock when you visit the official store, order immediately, because restocks tend to sell out within days.
Purchase and Delivery Process
Ordering is simple. RootQuill is sold exclusively online through its official store, which means no retail markups and no middlemen.
Here's the catch: it's frequently out of stock because demand outpaces supply. I personally had to wait two weeks before I could place my order because it was sold out.
If you see it available, order now. Once you check out, delivery is fast and free shipping is included.
Put the decision off and you may find yourself waiting for the next restock.
Where Can I Buy the RootQuill?
Getting your own RootQuill with a 50% discount is simple. Just follow these steps: