This Serum Is The Only Thing Keeping My Hair Smooth In The Humidity

In our series Trial Run, TZR editors and writers put the buzziest new beauty products to the test and share their honest reviews. This week, deputy beauty editor Erin Lukas is testing the buzzy Crown Affair The Overnight Repair Serum.

My hair care routine reads “lazy girl” out of practicality, not an unwillingness to put in the work to keep my color-treated deep brunette strands soft, shiny, and vibrant. I’m down to add a weekly nourishing mask, but I’m not up for having to first dampen my hair, wait around for it to marinate, then hop back in the shower to rinse it out. While oils can be an alternative option, I’m not looking to stain anymore pillowcases (my retinol serums have ruined enough of them). Essentially, my ideal hair treatment is a leave-in that’s easy to apply, doesn’t weigh down my strands, and won’t result in a trip to the laundromat every time I use it. Enter Crown Affair’s The Overnight Repair Serum.

When I caught wind of the brand’s latest launch during a Zoom meeting with founder Dianna Cohen, it legitimately felt like she was reading my mind when creating this product. Inspired by face serums, the overnight treatment is designed to be low-maintenance while providing maximum results in the repair department — especially if you have split ends, breakage, and/or dryness. Needless to say, I immediately added it to my routine.

Keep reading for my honest thoughts on the new addition to Crown Affair’s lineup.

Fast Facts

• Price: $58
• Size: 3.3 fl oz/97 ml
• Best For: Dry hair, split ends, dullness
• Ingredient Highlights: Flaxseed and chia seed extracts, tsubaki and meadowfoam seed oils, rosemary leaf extract
• What We Like: Fresh, subtle scent; doesn’t weigh down hair; helps with frizz control
• What We Don’t Like: Nothing so far!
• Rating: 5/5

How TZR Keeps Score: 1/5: Making a return; 2/5: Keeping as a backup; 3/5: Finishing to the last drop; 4/5: Recommending to my group texts; 5/5: Already on auto-replenish

The Formula

While Crown Affair’s serum is lightweight compared to rich hair masks or treatment oils, it’s just as effective. It’s formulated with a superfood blend of flaxseed and chia seed extracts that work to repair and strengthen strands to prevent future damage, including split ends and dryness. The brand has also included its signature tsubaki and meadowfoam seed oil blend to deeply nourish hair, and rosemary leaf extract to boost softness and shine. This serum is also pH balanced to help seal the hair cuticle, retain moisture, and in return, your results. Like the rest of the line, it has Crown Affair’s cult-favorite spa-like signature scent, a fresh blend of sparkling yuzu, green tea, bergamot, and sandalwood.

In the brand’s four-week clinical trial, the formula was shown to strengthen hair up to two times after one use, smooth and soften hair two times after one use, reduce breakage by 75% over one month, and provide over eight hours of frizz protection.

My Typical Hair Care Routine

Routine bang trims and root touch-ups aside, my hair is admittedly the most low-key part of my overall beauty routine. I have thick, slightly coarse, dry strands, so I use a hydrating shampoo and conditioner when I wash it (usually three times a week). Coincidentally, Crown Affair’s The Hydrating Shampoo and Conditioner are currently in my shower. The duo effectively cleanses oil and buildup without stripping my strands and offers deep nourishment that doesn’t leave a filmy, greasy residue. If I’ve just gotten my hair colored, I’ll skip conditioner for one or two washes to treat my strands with K18’s Leave-In Molecular Repair Hair Mask in an effort minimize any wear and tear that may have occurred during the chemical treatment. Otherwise, once I’ve towel-dried my clean hair, I’ll saturate it with Chris McMillian’s The Glassy Smooth Blowdry Spray. Unfortunately, air-drying isn’t a reality for me so a heat protectant is a must. This one shields against hot tools while boosting shine and moisturizing strands.

My Experience & Results

I was two days post-hair wash when I received my bottle of Crown Affair’s The Overnight Serum in the middle of a mid-summer heatwave. That night, I gently brushed my hair, then warmed up the four pumps of the product in the palms of my hands before running it through my mid-lengths to ends. I was taken aback by how quickly the serum absorbed into my hair (nearly instantly) so I went to bed with my strands pretty much dry. The next morning I woke up with soft, smooth strands — and zero residue on my pillowcases. What impressed the most was that my hair stayed frizz-free throughout the day, despite it being a 90-degree day with 70% humidity.

For the past three weeks, I’ve continued to use the serum three or four nights a week in-between wash days. While I can’t speak to how it helps heal split ends, my dry, frizzy hair has been significantly softer and smoother than it usually is during the summer.

Is Crown Affair’s The Overnight Repair Serum Worth It?

Regardless if you’re looking to completely rehab your hair or you’re just in need of a little jumpstart, this serum would be a welcome addition to your routine. Whether you use it every night or a few times a week like I do, you’re getting maximum payoff with minimal extra effort. A win-win if you ask me.