Lindsay Lohan is spruiking a potentially harmful dieting fad.

Lindsay Lohan’s acting career has taken a quiet turn in recent years, but the actress is still active on social media.

The Mean Girls star’s Instagram is full of the usual celebrity fare — throwbacks to old movie roles, outfit selfies, ‘makeup free in bed’ shots — but this week we’ve noticed she’s been spruiking some products that promise dubious ‘health’ and beauty benefits.

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Yesterday, it was coconut oil that claims to whiten teeth; and just a few hours ago, Lohan shared a photo of her posing with two packets of 14-day detox tea.

"Love my @booteauk teatox! So easy to use on the move," the 28-year-old captioned the shot.

This is the second time Lohan has promoted the UK company on her social profiles — in March, she shared a similar photo, wring: "Getting ready for a healthy spring with @booteauk #majorsituation".

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For the uninitiated, detox tea is exactly what it sounds like — tea that purports to "detox" the body (this is known as 'teatoxing). And Lohan isn't the only celebrity who's climbed on board the bandwagon. (Post continues after gallery.)

Earlier this year, model Kendall Jenner told E! News she uses detox tea to get her body ready to walk the catwalk. “I usually start my day off with a cup of detox tea. I have like 12 cups a day,” she said, describing her Milan Fashion Week preparation. Giuliana Rancic also reportedly shed three kilos before her wedding by following the 'Ultimate Tea Diet'.

This might sound like yet another niche Hollywood health fad, but teatoxing has well and truly hit the mainstream over the past few years.

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There are a number of brands and programs floating around, all making various claims about the impact their usually herbal brews can have on health, including weight loss, reduced bloating and clearer skin. Some of these programs, including Lohan's favourite Bootea, advocate adding detox teas to the diet for up to two weeks.

Does that sound iffy to you? Nutrition experts tend to agree. “I think [teatoxing] goes into the ‘extreme measures’ basket; it’s not recommended for any length of time,” Accredited Practising Dietitian and Nutritionist Nicole Senior told The Glow.

Senior says that while detox teas are generally safe, many of their health and medicinal claims, like an easy route to weight loss, aren't substantiated. She suggests that any changes to weight are likely to come about because less food is being consumed while the teatox is underway.

What really perplexes many health experts about so-called 'detox' programs and cleanses is that the human body is already perfectly capable of detoxing itself. Sure, the mental process of "going on a detox" might bring about a healthier approach to someone's lifestyle, which is a positive thing, but it doesn't actually bring about physical effects the liver isn't already producing.

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“There’s nothing in particular in a herbal tea that’s going to miraculously undo any damage you’ve done by poor lifestyle. In terms of your liver, that’s drinking too much alcohol and not eating enough nutritious core food,” Senior explains.

“Eating badly and then going on a detox with lots of tea isn’t going to undo the damage, and it’s not really a sustainable approach.” (Post continues after gallery.)

What does raise concern is that some brands of teatox, particularly those claiming to offer 'colon cleansing' properties, use an ingredient called senna, which can have a laxative effect and cause headaches, nausea and dehydration.

In 2013, the Australian Medical Association cottoned onto this phenomenon, and issued a warning about the use of laxative-based products when they aren't actually required. The body urged prospective 'teatoxers' to read labels carefully and consult a nutritionist before embarking on the diet program.

RELATED: Professor tests Gwyneth’s health advice: “It’s incredible how much she’s wrong about.”

These days, more and more celebrities are throwing their hats into the 'healthy living' arena. Aussie model Miranda Kerr loves to encourage her followers to embrace yoga and clean eating, while Gwyneth Paltrow has created an entire empire out of her approach to health and wellbeing, which includes detox cleanses.

The problem is, they're often promoting quick-fix measures. According to Professor Timothy Caulfield, who recently put Paltrow's health claims to the test in his book Is Gwyneth Paltrow Wrong About Everything?, the public's trust in traditional sources of scientific information seems to be shifting — and celebrities are swooping in.

"Social media plays a big role in that. I don't think people consciously say, "Let celebrities step in." But they have. Their voices are louder and seem more credible. And other counterweights in society, for whatever reason, seem to have less credibility," he tells Vox.

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"The scientific community has to get engaged, use celebrity culture as a Trojan horse to talk about what science says in these areas, and step in."

Lindsay Lohan is an adult, and she can do whatever she wants with her body — teatoxes, oil pulling, the lot. But perhaps it would be wise for her to understand the products she uses before encouraging her 3.7 million followers to spend their money and copy her habits.

Have you ever tried a dieting fad? Do you think celebrities should spruik them?