Get your hair to grow with these miracle grow vitamins for long hair and healthy hair.

Maybe your hair has always been on the thin side. Or maybe it’s lost its fullness as you’ve gotten older. (Yes, hair ages, too. Sigh.) Either way, there’s only so much that backcombing and volumizers can do. More and more, women are turning to hair supplements to give their roots a boost from the inside. Some experts recommend certain vitamins and targeted oral treatments supported by promising research and positive real-world results.

QUIZ: Who's Older—You or Your Hair?

Can you really get gorgeous hair by popping a pill? We looked at five popular options to see what works and what may leave you—and your hair—flat.