We tested 8 hair growth serums for 3 months — here's what actually worked
From Mielle Rosemary Oil, a cheap viral favorite, to Hårklinikken's $100+ custom formula, the 5 best hair growth oils and serums made the cut.
Holly Pevzner
Senior Writer, Health
About Holly
Holly Pevzner is Yahoo's Health Editor, where she edits health and product review content, works closely with a network of vetted writers and testers, and personally evaluates products across categories, including mattresses, compression socks and sneakers. She also co-developed Yahoo Health's testing methodologies for mattresses, hair loss treatments and other wellness products. Every recommendation she makes is benchmarked against guidance from leading medical organizations and informed by more than 25 years of experience in health journalism. Her background includes senior editorial roles at Self, Prevention and Fitness magazines, regular health columns for First for Women and Prevention, and 10 editorial awards recognizing her work in health and nutrition. That experience shapes how she evaluates products — not just by comfort, convenience or price, but by how they may support readers' health and well-being. She's skeptical by nature: if the science doesn't support it, neither does she. When she's not evaluating mattresses or wellness gear, she enjoys the Los Angeles sunshine (with a hat and SPF) alongside her husband, two sons and rescue mutt.
76
Articles on Yahoo
29
Years writing
10
Editorial awards
Areas of expertise
- Health
- Wellness
- Sleep
- Behavioral science
- Children's health
- Women's health
Latest articles
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Vegamour GRO+ Shampoo review: Can a shampoo really fill in a thinning hairline? The science says barely. Our tester says otherwise.
After four months with Vegamour's $104 GRO+ Advanced Balancing Shampoo and Conditioner, our tester is recommending the shampoo to all her friends, but definitely not the conditioner.
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Podiatrists say this shoe feature matters more than cushioning — and most people ignore it
While plush foam feels great in the store, there's the 10-second test foot doctors use to find a pair that'll actually still feel good at hour eight.
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The best cooling mattresses of 2026, tested and ranked
We tested and reviewed over two dozen cooling beds and found that only a handful help hot sleepers stay comfortable through the night.
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'I see this every shift': ER doctors share the risky habits they want you to quit now
E-bikes, GLP-1 shortcuts, fake lashes and more: five emergency room doctors name the everyday habits landing more and more people in the emergency room — and their prevention strategies.
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9 best hybrid mattresses of 2026, tested and reviewed
Helix, Bear, Sealy and more: these hybrid mattresses balance support, pressure relief and breathability — and actually held up in real-world testing.
