Nécessaire’s Rosemary Serum Is Responsible for My Crazy Summer Hair Growth

To know me is to know I’ve been on a hair redemption journey for four years now. After losing nearly half my thickness due to a combination of COVID-19, a GLP-1, and hormonal changes, I’ve been determined to get my density back and make my existing hair grow faster. My hair growth routine knows no bounds: my blood has been injected back into my scalp to stimulate the follicles (a process known as PRP), I’ve tried scalp microdermabrasion, started getting monthly trims, and completely overhauled my at-home routine.

My shower is similarly stocked: there are hair growth shampoos, volumizing conditioners, and an exorbitant number of scalp scrubs. (Hair isn’t going to grow on an irritated scalp!) But one of the most impactful additions I’ve made to my hair growth routine happens right out of the shower—with Nécessaire’s new Rosemary Serum, which is available today, August 5. I’ve been secretly testing it out for a few weeks, and my hair feels stronger and thicker already. My full, honest review, ahead.

The Formula

• Rosemary: There’s not a ton of research out there, but it’s widely believed that rosemary water, oil, and extract likely have a positive effect on hair growth. “It improves scalp circulation, stimulates hair follicles, and creates a healthy scalp environment with its anti-inflammatory and anti-microbial properties,” board-certified dermatologist Joyce Park, MD, previously told me.
• Capixyl: I’ve seen capixyl on the back of INCI lists here and there, but I never really knew that it was one of the most clinically-tested and proven-effective ingredients for fuller, denser, healthier hair. This serum contains five percent, which is the recommended over-the-counter concentration for maximum results without irritation.

The Application

Whenever it comes to scalp serums, my number one concern is that it’s going to weigh down my already fine hair or make my roots look greasy or wet. But! It’s my job to test and see. So right after getting out of the shower, I took a dropper full of the serum and slowly released the liquid onto my part. I used my fingers to section a few other scalp runways (about three on each side of my part) and repeated the process. In total, I probably use about two and a half full droppers per use.

I like to take the tips of my fingers and massage the liquid all in. Does it do anything extra? To be determined, but the extra circulation certainly can’t hurt. Then I’ll brush my hair one more time with a wide-tooth comb and heat style as usual.

The Results

Let’s start off the review from a cosmetic standpoint. Texture-wise, this gets a 10 out of 10. I hate when my hair feels sticky or if there’s any lingering residue. I genuinely don’t think my hair feels any different once I’ve blow-dried it, so that’s a huge win. I’ve experienced no irritation or itchiness, another win given my extremely sensitive skin.

As for the growth? The biggest thing I’ve learned on my hair journey is that real hair growth takes time. It doesn’t happen overnight. I’ve consistently been taking care of my hair and scalp for years now, but over the past month, my growth has been pretty dramatic. I can’t attribute it entirely to this serum (I do the most!), but it’s certainly helped my hair feel thicker, fuller, and stronger over the past four weeks.

The Takeaway

I’ve come a long way, but I’m still trying to get another three to four inches of growth out of my hair—and the faster, the better. Nécessaire’s new serum is certainly helping move along the process. I’ve noticed less shedding already, and given how easy it’s been to incorporate into my routine, I plan on continuing to use it every day. Fingers crossed that in three months, I’ll have some new baby hairs sprouting at the top of my head. Stay tuned!

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