About 5HT

5HT is a health newsletter from Derek Flanzraich, founder of Greatist. Each week, Derek shares five ✋healthyish things to help readers think clearer, live healthier, and age better.

Derek has spent his career driven by a simple belief: Health (and health content) should be more accessible, less alarmist—and, yes, actually kind of fun 🤪.

He started with Greatist, the health media company he grew to 20M+ monthly readers before it was acquired by Healthline in 2019. He later launched Ness, a venture-backed health startup, and has since worked with dozens of leading companies, including GoodRx, Parsley, Midi, Ro, LMNT, BetterHelp, and NOCD.

5HT was born from the same belief—making evidence-based wellness easier to swallow, with a healthy dose of humor. The name comes from 5-HT 🧬, the scientific name for serotonin , the chemical messengers in your brain tied to mood and motivation.

Each issue delivers one thing you’ll forward, one thing you’ll screenshot, one thing you’ll laugh out loud at, and two things that make you say, “I needed that.” Readers describe 5HT as “quick, fun, smart takes from a wellness wiz kid” 😆 and “your funniest, smartest friend sending you a weekly cheat sheet on what actually matters in health.” (We’ll take it.)

Since launching in 2024, 5HT has grown to over 100,000 subscribers 🚀 and expanded into Special Reports—longer-form deep dives on timely topics like microdosing GLP-1s and microplastics—as well as a 5HT+ Slack community, where readers debate, geek out, and compare notes on the latest health trends.

And the impact is real. More than 70% of readers report feeling strongly “healthyish,” and over half say they’ve continued researching topics they first discovered through 5HT. It’s the healthyish-est corner of the internet—and everyone’s invited.