Does rosemary oil work for hair growth? The science

rosemary oil hair loss

Is rosemary oil a natural, science-backed treatment for hair growth?  According to a lot of doctors, scientists and trichologists across the internet, yes – there’s “scientific proof” that it works as well as minoxidil. But unfortunately, that isn’t true. It all seems to be a misunderstanding of a single study: Rosemary oil vs minoxidil 2% for the treatment of androgenetic …

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Why you can’t trust study abstracts

One of the biggest sources of myths in beauty is misunderstanding how scientific research works, and how to interpret scientific evidence. A huge problem I’ve seen is people relying on abstracts – the short summary of the paper – instead of reading the full text. Here’s why this isn’t a good idea. This article is based on part of this …

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Why “scientific” products don’t always work: mechanistic reasoning

good bad mechanism outcome

There’s a troubling pattern with a lot of “science-based” cosmetic products. Many of them make claims solely based on mechanistic reasoning, rather than any actual measured effects on humans.  This is a big problem because mechanistic reasoning often doesn’t predict what happens on actual humans – and it’s especially the case with the ways these claims are often used for …

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Why “peer reviewed” studies aren’t reliable (especially for beauty science)

peer review process

There are a lot of myths in beauty, and over the years, I’ve noticed that a lot of them come from misunderstanding how science and scientific evidence works.  Here’s one big misconception: the idea that if a source is “peer reviewed”, it’s automatically higher quality than a source that isn’t. Unfortunately, it isn’t any sort of guarantee, especially for a …

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DMDM hydantoin and formaldehyde in haircare

Tony Youn dmdm hydantoin

DMDM hydantoin is a preservative commonly found in shampoos. It started getting a lot of attention in 2021, thanks to a number of lawsuits surrounding hair loss – so let’s talk about the science behind it and whether it’s safe. (This post is partly based off a longer video about haircare misinformation on TikTok, which also covers sulfates, silicones, testing …

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How to find transfer-proof eyeliner pencils

smudgeproof eyeliner seal

Something that made a big difference to me in 2023: I worked out how to find eyeliner pencils that were transfer-proof even on my oily skin!  My eyelids are super oily, so eyeliners always smudge or start transferring after a few hours. Transfer-proof pencils aren’t really that new an innovation, but for the longest time I didn’t really know what …

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How do colour-changing lipsticks and blushes work? The science

Red 21 Red 27 colour changing

Have you seen colour-changing lipsticks and blushes online? A lot of these claim to “adjust” to your skin’s pH to give a personalised shade… but is it just a gimmick? Here’s the chemistry behind these products. Colour-changing ingredients Red 27 Most colour-changing products – whether lipsticks or blushes – contain an ingredient called Red 27, also listed as CI 45410 …

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