Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

50+: Live Better, Longer

Font Size

How Old Are You Inside? Blood Test May Tell

Researchers Report Development of a Blood Test to Check People's 'Molecular Age'

Molecular Age Results continued...

Exercise was linked to lower levels of p16. It's not yet clear if exercise lowers p16 levels, or if people who exercise have low p16 levels for some other reason. Perhaps those people have diet habits that keep their p16 level low, Sharpless says.

"I really wouldn't want to make the mistake that has been made recurrently in epidemiologic association studies that try and place some causal relationship between the two, other than just note that there's a strong relationship that's reproducible," he says.

BMI (body mass index) wasn't related to p16 after the researchers took age into account. That finding surprised Sharpless.

"I would have thought that people who were thinner would have lower p16 for their age. That wasn't true," Sharpless says. "One could infer from that that body mass is not a great predictor of fitness ... it just turned out to be a bad marker of molecular age for us."

Test's Uses

Sharpless sees several possible uses for the p16 blood test.

For instance, he says the test could be used as a way to determine which patients are eligible for certain medical treatments that have age limits. "There are some really healthy 70 year olds out there who are very fit and can have fairly aggressive therapies, and then there are some people who are two decades younger who are not so fit, who are sort of prematurely old," Sharpless says.

He also sees the p16 test as a tool for researchers to explore whether anti-aging candidates -- such as resveratrol or green tea -- really delay aging.

"I jog and try and drink green tea or red wine," Sharpless says. "But wouldn't you like to know, if you're doing that stuff for decades at a time, that it's working? Wouldn't you like some solid evidence that these sorts of wellness behaviors are really doing what you're intending them to do?"

Sharpless worries about how the test might be used by health insurance companies or employers.

"I think we have to be careful about how you would apply such a marker," he says. "This is an issue we're going to have to face in the future as a society."

Today on WebMD

Eating for a longer, healthier life.
woman biking
How to stay vital in your 50s and beyond.
womans finger tied with string
Learn how we remember, and why we forget.
man reviewing building plans
Do you know how to stay healthy as you age?
fast healthy snack ideas
how healthy is your mouth
dog on couch
doctor holding syringe
champagne toast
Two women wearing white leotards back to back
Man feeding woman
two senior women laughing