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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Ultimate Guide to Drug Retinoids

drug retinoids thumbnail

Drug retinoids – tretinoin, adapalene, tazarotene and trifarotene – are some of the most powerful ingredients in skincare. They can help with issues like acne, uneven texture and hyperpigmentation. But what are the differences between them? Here’s the guide for you! My PhD is in medicinal chemistry, so I’m going to be diving into the differences at a drug structure …

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