Q. It seems like everyone I know is going on the hCG diet -- a combination of hormone injections or drops and a 500- to 700-calorie diet. My instinct is that the extreme diet is the real cause of the weight loss. I think there's something not right about using this hormone, but people taking it rave about their rapid weight loss. -- Anna, via e-mail A. You've got good instincts! It's true: If you go on a very-low-cal diet while taking human chorionic gonadotropin or hCG (which, by the way, comes from the urine of pregnant women), you'll definitely lose weight. But you would without a hormone, too.

The idea that hCG speeds up fat-cell loss goes back to the 1950s, but its reputation faded when several studies found that the hormone didn't give dieters an edge. Then in 2007, a book called "The Weight Loss Cure 'They' Don't Want You to Know About," by Kevin Trudeau -- a controversial infomercial self-proclaimed health maven -- gave hCG dieting a popular second act. The Federal Trade Commission ordered Trudeau to pay $5 million in profits from the book for making false claims.

Like any hormone treatment, this one has health risks: Women may develop ovarian cysts, blood clots and -- since hCG affects fertility -- surprise pregnancies. In men, hCG stimulates rapid testosterone production. That may sound good, but the long-term consequences include developing breasts ... so maybe not. Bottom line: There are far healthier ways to lose weight.

Q. What is the danger of eating too much protein? -- Anonymous

A. Even though metabolizing large amounts of protein makes your kidneys work harder, reports that it can bring on kidney failure are exaggerated. However, you could become dehydrated, which can make you feel pretty crappy, because your body uses extra water to flush out extra urea, a byproduct of protein digestion.

Also, if you go for protein stuffed with more saturated fat than a bacon-wrapped cheeseburger and you're obese, your odds of insulin resistance and diabetes shoot up like Old Faithful.

There's a simple way to gauge how much protein you need: Multiply your weight in pounds by 0.4. If you're 165 pounds, that's about 66 grams of protein. Anything more will be turned into fat and pee, though don't try telling that to the average gym rat who thinks high-protein shakes are magic muscle makers.

Elite athletes may need somewhat more protein than the rest of us, but most Americans get plenty of protein.

So do your math, stick to your daily protein requirement, and do what we do: Get most of your protein from plants, like kidney beans, tree nuts and edamame (16-18 grams of protein per cup). With vegetarian protein, you get other benefits, too, like fiber, protective plant phytochemicals, fewer calories and no saturated fat.

Q. Recently I watched a Dr. Oz TV segment on cholesterol medications. You didn't mention guggul. Do you have an opinion about it? -- Marsha, via e-mail

A. It all depends on your dosha (Sanscrit for "body type"). No, we haven't gone Bollywood, but we are seeing a resurgence of interest in India's traditional Ayurvedic medicine. And some herbals, including guggul (made from myrrh tree resin), may be more than just a curiosity in the Ayurvedic remedy cabinet.

By alternative-medicine standards, guggul has been studied fairly often. A recent review of the research found that guggul helped lower lousy LDL cholesterol and prevent heart disease in more than 80 percent of studies. There's also some evidence that guggul may have anti-tumor properties. Impressive, right?

Not so much. Few of the studies are great, and the best ones are discouraging. In fact, one well-designed trial found that guggul actually raised levels of LDL, the utter opposite of what you want! (Like going on a diet and gaining 20 pounds.)

Also, 15 percent of those who took it developed a severe-enough rash to make most throw in the towel. Finally, since guggul affects how your cells process drugs, scientists suspect that it could alter how roughly 60 percent of prescription meds work.

So guggul is not our go-to drug for lowering your lousy LDL cholesterol. It didn't make the TV show because it's not ready for prime time.

The YOU Docs, Mehmet Oz and Mike Roizen, are authors of "YOU: On a Diet." Want more? See "The Dr. Oz Show" on TV (check local listings). To submit questions, go to www.RealAge.com.