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The generation once known for embracing granola and peace is now popping pills and shelling out big bucks to keep a youthful appearance.

Baby boomers (search) are aging — but not without a fight.

American 40- and 50-year-olds are flocking to clinics and supplement stores, frantically trying to slow down the aging process.

Taking a daily vitamin supplement is child's play compared to some of the lengths people will go: injecting themselves with human growth hormone, rubbing testosterone on their bodies and taking a hormone supplement called DHEA (search).

"The baby boomers are becoming frantic," said Dr. Terry Grossman of the Frontier Medical Institute in Lakewood, Co., which offers an array of aggressive anti-aging (search) remedies and treatments, including human growth hormone injections that supposedly thicken the skin, and cell regeneration and supplementation.

The medical community continues to debate the effectiveness of these fountain-of-youth formulas, along with whether or not the aging process should be treated like a disease with a potential cure or a reality that’s inevitable.

"All treatments are double edged swords and there are both positive and negative potential effects to almost anything that you put in your body," said Dr. Robert Schwartz, head of geriatric medicine at the University of Colorado Health Services Center (search).

"And before we can suggest that any of these are things that people should actually go out and do we need to know enough about the positives and the negatives.”

At 76 million, the largest generation in American history is turning into a goldmine for the anti-aging industry. Grossman, author of The Baby Boomers Guide to Living Forever, said he pops 40 pills every day to turn back the hands of time.

Americans in their 40s begin noticing the cosmetic effects of aging such as wrinkles and age spots.

"In their 50s I think people get very serious about it … Almost everybody starts to take their health seriously because they start to notice things. Their energy changes, their sleep changes, their bodies begin to change," Grossman said.

But stopping Father Time's march isn't merely a cosmetic quick fix, and expectations should be kept in check, say some experts.

"Aging is a very complicated process," said Schwartz, adding that not enough is known about aging to recommend any so-called treatment, let alone prescribe substances like the controversial DHEA: a naturally occurring youth hormone that breaks down over time.

"We don't know what the side effects [are] of having thousands and thousands of people taking growth hormone, DHEA, or testosterone supplementation," he said.

In addition to other tests, anti-aging practitioners can determine a person's biological age versus chronological age — whether the body is older or younger than the birth certificate.

Schwartz said there is only one proven way for boomers to increase their lifespan and improve their health: Put down that pizza.

"It's been shown that if you reduce caloric intake on a chronic basis by 25 to 33 percent that you can in fact retard the physiological aging process," he said.

While eating less food might not sound as cutting edge as hormone injections, it's certainly less expensive.

And as both doctors point out — it's really up to you and your bank account.

Fox News' Amy C. Sims contributed to this report.