This TikTok Skin Trend Is Going Viral For Clearing Acne, But Here’s The Truth

Illustrated by Olivia Santner
Dear Daniela,
Is washing your face with a bar of soap good or bad for your skin? On TikTok especially, I’ve seen some people say that switching to bar soap has helped clear up their acne and others say that it really dries their skin out. To me, washing your face with soap is the most bachelor thing I can imagine, but I also hear a lot of people suggesting that going back to basics is good. Also, what are these soap bars for your hair? Help!

Lorraine, 27
Let me say this: if a man is washing his face with bar soap, at least he’s making face washing a dedicated step, rather than just letting the shampoo run-off trickle down. (If you’re reading this and you’re not coupled up or don’t date cis men, yes, it is that bad out there.) But your question gives me an opportunity to examine the current bar boom in beauty. From Glossier and Lush to Christophe Robin and Drunk Elephant – not to mention old-fashioned soap bars – the humble bar has never been so popular.
I put your questions to chemist and content creator, Michelle Wong PhD aka LabMuffin Beauty. Firstly, is a bar of soap good for acne? Essentially, no. "If someone says it made their acne go away, I would guess that’s either coincidence or whatever cleanser they were using before was even worse for their skin for some reason," said Michelle. This doesn’t mean that a cleansing bar would be bad for your skin because, as it turns out, not all bars are soaps. (And not all soaps are bars! Liquid hand wash, for one.)
Chemically speaking, "Soaps are fatty acid salts. They're made from reacting fats and oils with sodium hydroxide or potassium hydroxide, and the resulting soaps have names like sodium palmitate and sodium cocoate," said Michelle. This process of soap-making is called saponification and there is a difference between a soap and a detergent: soap is made by mixing fat with oils with some sort of base, whereas detergents are made by combining chemical compounds. Soaps can be quite drying, hence why detergents are sometimes needed. "These detergents are found in soap-free cleansers and shampoos," explained Michelle. 
Soap is a surfactant, which means it lathers up and helps to break down and disperse particles and grime. When you lather it with water, it kills microorganisms and washes away oil. Basically, soaps are very good at removing dirt! But that doesn’t necessarily make them the kind of cleanser you’d want for your face, as you don’t use your face like you do your hands, for obvious reasons. 
Then you have cleansing bars designed for a specified purpose, like the Drunk Elephant JuJu Bar, Glossier Exfoliating Body Bar or really any shampoo bar. "Bar shampoos and cleansers contain ingredients that are similar to liquid shampoos and cleansers but [as they are solid bars], they don't contain water," said Michelle. Because of the lack of water, some kinds of surfactants won’t work in those formulas and so, according to Michelle, they usually contain ingredients like sodium lauryl sulfate (SLS) or, sometimes, soap! It all comes full circle and these surfactants help lift up dirt. 
The real benefit of bars is twofold: the lack of water can make them more suitable for some skin types, such as sensitive or reactive skin, and their lightweight and skimpy packaging arguably makes them a more sustainable choice. "Water is fantastic for helping bacteria and fungi grow, and as bars don’t contain water, a preservative usually isn't required," said Michelle. "If you're allergic to a lot of preservatives, then a bar product might be easier than trying to find a cleanser that works for your skin," she suggested. "Otherwise," she went on, "there isn't much of a benefit for your skin with bar products but there can be other advantages, such as if you want to reduce your use of plastic packaging, if you want to save space and weight while travelling, or if you just prefer the feel of a bar."

In terms of body care, while I usually use shower gel or oil, I’m a big fan of the Dove Beauty Cream Bar when I’m travelling, which Michelle also named as one of her favourites, adding that she thinks the Lush Shampoo Bars are handy on the go. If you have sensitivity issues with regular cleansers and body washes, you should absolutely give bars a go. The sustainability score will differ from brand to brand: while bars can be wrapped in a little bit of lightweight paper or cardboard rather than using plastic or even glass, which can be heavy to transport, if eco-friendly credentials are a deal-breaker for you, I’d still recommend you look up the brand and research a little more.
Good luck!

Got a question for our resident beauty columnist Daniela Morosini? No problem, qualm or dilemma is too big, small or niche. Email, including your name and age for a chance to have your question answered. All letters to 'Dear Daniela' become the property of Refinery29 and will be edited for length, clarity, and grammatical correctness.

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