But with so many supplements on the market, how do you choose? And what about safety? Here's a heads up on some questionable ingredients.
Supplement sales totaled $28 billion in 2010, up more than $1 billion from 2009 with a big January surge.
"Consumers really start to make New Year's resolutions centering around a healthy lifestyle," says Taylor Wallace, senior director, Council for Responsible Nutrition.
Which supplements are right for you, and what's safe?
Registered Dietitian Erin Palinski says dietary supplements are regulated by the federal government as a category of food, not as a drug.
"Medications are tested and verified for potency and purity," says Palinski. "With dietary supplements, there is no testing standard, and that's where we can run into issues."
Looking at labels and ingredient lists is a must.
Protein, creatine and conjugated linoleic acid (CLA) are popular for building muscle. Studies on creatine and CLA are mixed, but all three are generally considered safe if taken at recommended levels.
But take too much there's risk of dehydration, increased risk for kidney stones, and gastrointestinal issues. Energy-boosting caffeine can be a concern over 300 milligrams.
"But above that amount we can run the risk, since it's a stimulant, of increasing blood pressure," says Palinski. "In very high amounts, it can actually lead to seizures."
And so-called fat-burning supplements with herbal blends can act as a stimulant.
"Long-term use of certain fat-burners can have some very adverse events in the liver," says Taylor Wallace.
Keep an eye out for ephedra, which has been banned by the Food and Drug Administration (FDA). And bitter orange, also referred to as synephrine, is related to ephedra. The FDA says there's little evidence it's safer.
"This has been linked with many serious side effects, including stroke, heart attack," says Palinski.
Another one to watch: geranium oil, sometimes seen as 1,3-dimethylamylamine (DMAA), which is amphetamine-like in nature.
Supplement expert Ellen Coleman says it's especially troubling for those with high blood pressure or who are overweight. But even healthy individuals taking it can be in danger.
"Heart attack, stroke, seizure and death," says Coleman.