This past weekend, many people held “march for science” demonstrations and gatherings across the country to protest…well, something, though it was hard to know exactly what. Predictably, entertainers like Rosario Dawson, Peter Capaldi, Kate Walsh, Kerry Washington, Debra Messing, supermodel (and destroyer of Pepsi) Kendall Jenner, designer Kenneth Cole, and television personality Bill Nye, The Science Guy were all supportive of the March and the vague positions promoted by the March organizers.

These elites are all entitled to their opinions and entitled to promote them on social media, but people shouldn’t mistake celebrity endorsement as a sign of legitimacy, nor should March organizers forget that celebrities make bad spokesmen for science.

It’s not that most entertainers are developmentally delayed, it’s that sycophants and paid-for-friends (hair dressers, stylists, publicists, spouses) have for so long surrounded them that many are incapable of any sort of self-doubt or self-examination. Lacking much intellectual humility or curiosity, they don’t exactly exude one of the tenets of the scientific process: the need to constantly question, and reevaluate evidence, as well as staying open to criticism by other scientists or new discoveries that would lead to a new conclusion.

Gwyneth Paltrow is a perfect example of how entertainers usually misunderstand complex scientific issues yet have no problem presenting themselves as knowledgeable experts on these serious topics.

For instance, in the weeks leading up to the March for Science, Paltrow tweeted a harrowing message to her 2.8 million followers, warning them that they’re being poisoned by their cosmetics because items like lipstick contain lead. Yet, if Paltrow had talked to an actual toxicologist (or even checked Snopes, which dismissed this hysterical nonsense in 2015), she would have learned that the level of lead (which is used as a color additive) in lipstick is so miniscule that it has no epidemiological effect on the human body. The FDA confirmed this on the agency’s own website, explaining that, after conducting safety tests on lipstick, they found that the lead levels were so low that the agency “does not believe that any of the products tested pose a safety concern.”

Of course, it’s understandable that people are nervous. Cosmetics do contain things that seem scary—like chemical preservatives with long, multi-syllabic names. That’s why it’s so easy to scare people about products one applies directly to the body. But what’s not talked about is just what these preservatives do—protect consumers from opportunistic bacteria that can cause real health problems, like breakouts, skin and eye infections, bumps and itchiness (For even more evidence that preservatives make cosmetics safer, check out this side-by-side view of cosmetics with and without preservatives and tell me which one you want to smear on your face).

Paltrow and her Twitter followers might also be reassured to know that the cosmetic industry is already heavily regulated by the Food and Drug Administration under the authority of the Federal Food, Drug, and Cosmetic Act and the Fair Packaging and Labeling Act. In other words, there’s a regulatory structure already in place to ensure the safety of the products that end up in your makeup bag.

Sadly, Paltrow is a known peddler of fake news from dubious sources. For that lipstick tweet, Paltrow provided a link to a report by the Environmental Working Group—a widely dismissed (by actual scientists) and very radical environmental group that pushes junk science in order to scare consumers into demanding tougher regulations on an already overregulated cosmetic industry (tip to the ladies: more regulations will lead to higher costs on your favorite blush and eye shadow).

Paltrow might also examine the health, beauty, and nutrition advice she promotes on her own lifestyle blog GOOP, which is far from scientifically sound. For instance, Paltrow provides guidance from a “naturopathic physician and homeopath” (otherwise known as “not really a doctor”) about how to rid oneself of the quite serious problem of parasitic infestation after vacationing in a tropical location: sit in a tub of goat’s milk to rid oneself of the parasite. Oddly, the Centers for Disease Control has other recommendations, like seeking actual medical help.

Paltrow also says bee stings are an effective treatment for skin irritations and to reduce the appearance of scars. She’s told women that vaginal steaming promotes hormonal health when it’s really just a good way to injure a pretty tender and important part of your body. Paltrow recommends invasive and totally unnecessary colon cleanses to rid one’s body of toxins (that’s what your liver does), starvation diets and food restriction, and that people should forgo “toxic” sunscreen during sunny summer months. Her nonsensical guidance would be comic gold if they weren’t so scientifically unsound and potentially harmful.

Americans need to remember that ill-informed, pretty people make good entertainers yet they make poor sources for information on science and other policy matters. Marchers for science, politicians, and the media reporting on health and wellness issues would do well to remember the distinction.