#9: Sunscreen misinfo, my top hair ingredient, tretinoin breaks down in light?

May update.

We’re entering sunscreen misinformation season, so we’re back to lots of sunscreen content! It’s a bit harder to talk about sunscreens with Australian regulations, but I have some pieces I’m working on that I’m really excited about - stay tuned…

Shorter content

My latest posts on Instagram and TikTok:

• Indoor lights don’t break down tretinoin

• Sunblock (mineral sunscreens) don’t prevent tanning better

• Seed oils don’t cause sunburn

• Debunking lip balm paper tests

• How colour-shifting pigments work

• How to make your eyes look bigger using an optical illusion (I learned this while writing my book, The Science of Beauty!)

Longer content

It’s time for another episode of debunking TikTok misinformation! This time it’s sunscreen.

This video actually got a shoutout in a Wall Street Journal article, which is very cool!

This episode covers:

• Paul Saladino’s DIY sunscreen

• Seed oils and sunburn

• SPF doesn’t mean time

• Chemical sunscreens and endocrine disruption, pregnancy

• Sunscreen is bad for your skin

• Huberman’s claim that sunscreen can be found in your brain 10 years after you use it

• Sunscreen cushion hack

• Chemical lip SPF - featuring my favourite toxicologist communicator, Mo’s Skin Lab (He’s great to follow, if you haven’t already! He’s also on YouTube)

• Bobby (as is tradition) - talking about breast milk, coral reefs and “100% non-toxic” sunscreen

You can watch it on YouTube and Nebula. Many of these myths have also been covered before in article form on my website:

• Answering Almost Every Sunscreen Question is a good starting point in general for sunscreen info

• US sunscreens “aren’t safe” in the EU is a deep dive into safety assessments

• Should you wear sunscreen indoors? is a classic

• Here’s an index of all my sun protection articles

• My eBook The Lab Muffin Guide to Basic Skincare also has a bunch of practical tips on choosing sunscreen, as well as setting up a skincare routine in general!

I also let time get away from me this month (yeah, what’s new…) so I’ve actually done another video since last time! This is more recommendation-heavy - it’s about amodimethicone, a haircare ingredient that’s really saved my hair. You can watch it on YouTube and Nebula.

This video is based on this article, but there are a lot of extra product recommendations!

Extra bits

• Pete Judo makes a lot of great videos on scientific misconduct - his recent video on the PACE trial (exercise therapy and counselling for ME/CFS) was fascinating/infuriating.

• I recently went on Radio New Zealand to chat to Jim Mora about a whole bunch of really interesting new skincare-related studies he’s found. Moisturisers linked to slowing cognitive decline, sugar affecting your facial appearance… you can listen here.

• A few of you asked me what I’m currently knitting - I’m working on an unstriped Lyon Sweater for Omar (it’s very boring, but he specifically requested boring), and I just finied a Mastiha Cardigan for myself!