Choosing retinol products: Neutrogena Rapid Wrinkle Repair Regenerating Cream

December 12, 2020

This post is sponsored by Neutrogena. Retinol is one of the most popular anti-aging skincare ingredients, but it’s also one of the trickiest when it comes to choosing a product, and one of the ones where looking at the percentage and analysing the INCI list doesn’t quite cut it. There’s a common perception that drugstore skincare is ineffective, and only …

Should You Wear Sunscreen Indoors? The Science (with video)

November 18, 2021July 2, 2020

Since so many of us are staying indoors more at the moment, I’ve had a lot of people ask me whether they still need to wear sunscreen inside. And I personally haven’t been wearing sunscreen indoors, even as a sunscreen nerd who owns all of the sunscreens. So do you need to wear sunscreen indoors? The truth is… it depends. “Indoors” …

Ascorbyl Glucoside Vitamin C: Avène A-Oxitive

June 21, 2020

This post is sponsored by Avène. I’ve been really happy to see more vitamin C products hit the marketplace recently. Vitamin C is one of my favourite skincare ingredients – it’s a powerful antioxidant that’s fantastic for soaking up free radical damage, which makes it great for evening out skin tone and reducing fine lines. As someone who’s very prone to …

Busting Retinoid Skincare Myths (with Video)

November 18, 2021May 7, 2020

Retinoids are vitamin A derivatives, and they’re some of the most popular ingredients in skincare. They’re anti-aging, anti-pigmentation and anti-acne, plus their effectiveness is backed by lots of studies. But like everything else in skincare, there are lots of myths and half-truths about how they work and how you’re meant to use them. Here’s the video on YouTube – keep scrolling for …

Easy (5 Minute) DIY Vitamin C Serum Recipe

November 15, 2021February 23, 2020

I’ve mentioned my super-easy DIY vitamin C serum a few times before on social media, and some of you have been asking me for the recipe… but I’ve been so distracted with other things I never got around to posting it until now. I’m sorry! Please forgive me. I hope the results make up for my tardiness!

Here’s the video (you may need to disable AdBlock to see it) – scroll down for the recipe. Click here to watch on YouTube.

What Does Vitamin C Do in Skincare?

Vitamin C is a superstar anti-aging ingredient in skincare. It tackles anti-aging on lots of levels:

Can increase collagen, which plumps up skin and decreases wrinkles
Fades hyperpigmentation (brown marks like acne scars and sun spots)
Acts as an antioxidant, protecting against free radical damage from UV, pollution and natural aging

Who wouldn’t want this, right? It does a bit of everything!

The Problem With Vitamin C

The big problem with using vitamin C in products is that L-ascorbic acid is very unstable in water-based products. It turns into yellow dehydroascorbic acid (DHA or DHAA) and other products very quickly: at pH 3.52 and 25 °C in amber glass, 50% is gone in a week. Luckily, DHA can convert back to L-ascorbic acid in your skin, and there’s no evidence that it’s bad for your skin (there’s actually a product with an accompanying non-peer-reviewed study that actually uses it as a way of getting vitamin C into your skin more easily). But there’s not a lot of evidence that it’s good either, and it degrades further into products that can’t be turned back into L-ascorbic acid.

L-Ascorbic acid can be stabilised by combining it with vitamin E and ferulic acid (plus it makes it work better). This is the approach used in serums from SkinCeuticals, Paula’s Choice, Timeless, Cosmetic Skin Solutions and Ausceuticals, However, if you want to DIY with this combo, it not only requires buying vitamin E and ferulic acid, but you’ll also have to get an emulsifier because vitamin E doesn’t play nicely with water.

And if you’ve gone to the trouble of mixing all that, you’ll also want a preservative to suppress bacterial growth so it’ll last longer and you won’t have to remake it any time soon. The price of all these ingredients adds up quickly, and if you’ve done any DIY before, you’ll know that you’ll end up with barely-used bottles that will go off before you finish them.

L-Ascorbic acid can also be stabilised by altering its chemical structure. Some derivatives of LAA include magnesium ascorbyl phosphate (MAP), and ascorbyl tetraisopalmitate (ATIP)/tetrahexyldecyl ascorbate (THDA). However, these are expensive compared to LAA, and they need to be converted back into LAA to work as effectively.

The Solution: DIY Vitamin C Serum

All these issues can be solved by using a DIY vitamin C serum that you remake every week or so. I generally find DIY a bit of a pain – the minimum orders of the ingredients are too large for me to use up personally so I end up spending way more money than using a pre-made product, and there’s the horrible feeling of wastage when you chuck out expired, barely-used ingredients.

There’s also the time required to cook up your product, the failed batches, and the dreaded washing-up afterwards. But it’s hard to find a downside to this DIY serum:

All the ingredients and materials are easy to get and inexpensive
It takes about 5 minutes to make with no special equipment required
It can be more effective than a store-bought product – you don’t have to deal with delivery times and distribution networks and having your vitamin C sit on a store shelf slowly degrading for an unknown period of time
You can easily adjust the amount of vitamin C in your serum – add more LAA to ramp up the effectiveness, or use less LAA to decrease irritation
It’s cheap enough that I don’t feel bad spraying it all over my face and chest and body

For an effective vitamin C serum, you need 5-20% LAA at a pH less than 3.5. Above 20%, the effectiveness of LAA doesn’t increase but the side effects (mostly irritation) do.

Bakuchiol: Better Than Retinol?

June 30, 2022September 13, 2019

Retinoids (vitamin A derivatives) are by far the most raved-about ingredients by both dermatologists and skincare junkies. They’re absolutely fantastic for treating both acne and the signs of aging skin. Unfortunately, retinoids tend to be irritating for most people, turning your face into a dry peeling mess if you’re too heavy-handed (me, a lot of the time). That’s why there’s a …

My Routine for Starting on Tretinoin (Retin-A) Cream (with video)

June 30, 2022June 16, 2019

I recently started using a prescription tretinoin cream, a generic version of Retin-A. Tretinoin is probably THE most popular and evidence-supported prescription retinoid (vitamin A derivative), and works as an acne treatment, for anti-aging, and a generous handful of other skin issues. I’ve had a lot of requests for advice and tutorials on how to start on retinoids, how to stop peeling, and what sort of routine to use while on them, so I can finally talk about it with first-hand experience and way too much detail!

Here’s the video version – keep scrolling for the blog post!

What is tretinoin?

Tretinoin, also known as retinoic acid, is an active form of vitamin A. It’s sometimes called all-trans-retinoic acid to distinguish it from isotretinoin (13-cis-retinoic acid), which is the active ingredient in the highly effective acne medication Accutane. Vitamin A derivatives (retinoids) are one of the most studied categories of skin actives, since they work really well to fix a range of things including acne, pigmentation and aging.

How Do Bubbling Oxygen Masks Work? (with Video)

November 18, 2021March 7, 2019

Oxygen masks are products which come out of the bottle as a gel, but start bubbling with oxygen gas after a few seconds on the skin. Brands like Bliss, Peter Thomas Roth, Dr Brandt, Oseque and Sephora have oxygen bubble masks. What do they do, and how did they get the gas into the bottle?

Here’s the video, scroll down for the text version…

How do oxygen masks work?

Oxygen masks work a lot like soda water or soft drinks, where gas is dissolved in water under pressure (carbon dioxide gas, for soda), and is released when the pressure drops (when you open the bottle).

Oxygen doesn’t dissolve as well in water, so instead it’s dissolved in chemicals called perfluorocarbons, which are stable, unreactive carbon-based compounds containing fluorine atoms. They can dissolve 20 times more oxygen than water, and have even been investigated for use in artificial blood.

These oxygenated perfluorocarbons are then sealed in a pressurised bottle. When the mask comes out, the oxygen starts fizzing out slowly like the bubbles in soft drink. For some thicker products, a pressurised bottle isn’t required – the thickness of the product itself is enough to hold the oxygen until you massage it out by applying it on the skin.

The most commonly used perfluorocarbons in cosmetics are perfluorodecalin and methyl perfluorobutyl ether, but pretty much anything in the ingredients list with “perfluoro” in it will be a perfluorocarbon. Here are the perfluorocarbon ingredients in some popular oxygen masks: