Here are a few cleaner, more engaging versions of your headline:
💇‍♀️ Simple & clear
“How Often Should You Wash Your Hair? A Dermatologist Explains”
✨ More natural
“A Dermatologist Explains How Often You Should Really Wash Your Hair”
📱 Social media style
“How often should you wash your hair? A dermatologist finally clears it up 👩‍⚕️”
🔥 Clickable but clean
“Not every 2 days or 4 days—so how often should you wash your hair? Experts explain”
đź§ Slightly more informative hook
“How often should you wash your hair? A dermatologist says it depends on your hair type”
If you want, I can also write the full article-style answer (based on hair type, scalp oil, and lifestyle) 👍