Celebrities dole out advice on a variety of topics, but when it comes to health and medicine, you may want to steer clear of some of their recommendations.

Gwyneth Paltrow

On her lifestyle blog Goop.com, Gwyneth Paltrow suggested women try a spa steam treatment for their private parts, calling it "an energetic release - not just a steam douche - that balances female hormone levels." But doctors discourage douching, as it disturbs the natural flora of the female reproductive system, increasing the risk of urinary tract infections and yeast overgrowth.

A later post on her site by Dr. Habib Sadeghi suggests a link between breast cancer risk and wearing a too-tight bra, a claim that has been discredited by major health organizations, including the American Cancer Society.

Jenny McCarthy

Jenny McCarthy is one of the most well-known proponents of the anti-vaccination movement, a small but vocal faction who refuse to vaccinate their children due to fears that it will lead to autism. The belief stems from a 1998 study which was later found to be based on fraudulent data and discredited by the medical community. Numerous large-scale studies over many years have found no connection between vaccines and autism.

Jim Carrey

Funny man Jim Carrey - ex of Jenny McCarthy - is also very vocal in his beliefs that toxins in vaccines cause autism. In the summer of 2015, the comedian landed himself in hot water when he tweeted a photo of a boy with autism while expressing his dismay that California Governor Jerry Brown signed a bill requiring all children attending school to be vaccinated, regardless of personal or religious beliefs.

However, Carrey used the photo without permission and the boy's family posted on social media that they were "disgusted and sickened" by the actor's actions. The boy had the medical conditions before he was ever vaccinated, his family stated.

Mayim Bialik

"The Big Bang Theory"'s Mayim Bialik, a neuroscientist as well as an actress, has also spoken favorably about ingesting her own placenta after giving birth. In a 2012 blog post, she argued that "human beings are the only mammals that have chosen to not routinely ingest their placenta, which is consumed by every other mammal for its protein and iron-rich properties that are critical in helping the mother's body recuperate after giving birth. End of story."

But despite celebrity backing, a 2015 study found no evidence to support claims of health benefits from eating the placenta.

Tom Cruise

In 2006, Tom Cruise publicly criticized actress Brooke Shields for taking antidepressants to help with her postpartum depression. While Shields later said the actor came over to her house to apologize, Cruise's rep told the Associated Press at that he had not changed his position on antidepressants.

While antidepressants are generally considered safe for most adults, the FDA lists a number of side effects, including the increased risk of suicide in children, adolescents and adults ages 18 to 24. Cruise is a Scientologist, and the group opposes the use of antidepressants and other aspects of mainstream psychiatric care.

Suzanne Somers

In her 2013 book "I'm Too Young for This!: The Natural Hormone Solution to Enjoy Perimenopause," Suzanne Somers touted the benefits of bioidentical hormones - otherwise known as natural hormone therapy - as a safer alternative to ease symptoms of menopause that have fewer long-term risks and side effects than other hormone treatments. But experts quickly warned that while these hormones may be "natural" in origin, there's no evidence that the ingredients are safer, let alone superior to other therapies on the market.

Dr. Mehmet Oz

Dr. Mehmet Oz, host of "The Dr. Oz Show," is proud of helping millions of viewers with their health concerns. But he came under fire at a Congressional hearing in 2014 for promoting the supposed fat-burning benefits of green coffee bean extract - a product accused by the Federal Trade Commission of making fraudulent claims. Dr. Oz's credibility was also hurt by a 2014 study finding that fewer than half of his on-air recommendations - just 46 percent - were backed up by medical evidence.

Kim Kardashian

In the summer of 2015, reality star Kim Kardashian, pregnant with her second child, began promoting the prescription pill Diclegis to treat morning sickness through an endorsement deal on her social media accounts. But regulators from the U.S. Food and Drug Administration quickly stepped in and said that the posts violated federal rules for promoting drugs because they didn't mention its side effects - including drowsiness that can make it dangerous to drive, and warnings that it should not be combined with alcohol or other medications that cause sleepiness.

FDA regulations require manufacturers to balance benefit claims with information about drugs' risks, even when space is limited. Kardashian removed the initial ads and later posted updated ones, following the FDA rules.

Jessica Alba

To shed baby weight after giving birth, Jessica Alba said she wore a double corset to "retrain" her waist. While women have been attempting to make their wastes tinier by wearing corsets for centuries, the practice has been growing in popularity in the last year with celebs like Alba touting its benefits.

But experts say the effects from waist trainers don't last. "These women who are wearing these corsets are fully grown adults so there's no reason to suppose that by tying a tight corset around is going to do any permanent change," Dr. Mary Jane Minkin, clinical professor at Yale University, told CBS News.

Alicia Silverstone

Another advocate of placenta eating and the anti-vaccination movement, actress Alicia Silverstone also wrote a parenting book last year with some very questionable advice. In "The Kind Mama: A Simple Guide to Supercharged Fertility, a Radiant Pregnancy, a Sweeter Birth, and a Healthier, More Beautiful Beginning," Silverstone suggests a plant-based diet can help prevent miscarriages and stave off postpartum depression.

Alana Stewart

Actress Alana Stewart, the former wife of Rod Stewart, said in 2012 she'd used human-growth-hormone therapy to keep her hair from turning gray. But the U.S. Federal Trade Commission has cracked down on products making such unfounded claims, and the Mayo Clinic lists carpal tunnel syndrome, swelling in the arms and legs, joint and muscle pain, and for men, enlarged breast tissue, as possible side effects from the hormones.

Shailene Woodley

"Divergent" star Shailene Woodley says she eats clay to remove heavy metals from the body and recommends other women do the same. She also suggests getting a little sun on your vagina for some extra vitamin D.

Miley Cyrus

In 2012, after receiving criticism that she was too thin, Miley Cyrus took to Twitter to announce that she has a gluten and lactose allergy. She went on to tweet that everyone should try to go gluten-free for a week, saying "The change in your skin, phyisical (sic) and mental health is amazing! U won't go back!"

But doctors say that a gluten-free diet is only prescribed to people with celiac disease, a condition that causes the immune system to react to gluten in the body, causing damage to the lining of the intestines, along with uncomfortable gastrointestinal symptoms. For people without the disease, foods that are gluten-free have no special health benefits, and some gluten-free snacks may actually contain more fat.

Katy Perry

In 2013, Katy Perry revealed that she takes 26 vitamins and supplements a day and even tweeted a photo of herself with all her capsules. But experts say routinely overloading on vitamins can have the opposite of the intended effect, and may lead to symptoms including nausea, diarrhea, stomach cramps, hair loss and fatigue.

A recent study also found that use of dietary supplements leads to more than 23,000 emergency room visits per year due to adverse reactions.