I just had a look through some of the clinical trials – the ones that had details on the amount for the face had “pea-sized”, or it was dissolved into a solution and they just applied it all over their face. So I think “pea-sized” is probably the instructions given in the studies too…

Honestly I don’t think it’s that strict – tretinoin was approved in 1971, ever since then the instructions have been “pea-sized amount”. I just judge based on the size of the frozen peas in Australia, but there’s a good chance they’re not the same size as a pea in the US in the 1970s… I’d recommend just using an underestimate at first, and adjust based on your skin’s reaction.

Very informative!!

Hello, do you recommend using Tretenoin 0.025% on the entire face or just the target area like a bit of melasma forming near the cheeks, old acne scars and smile lines?

I have a question about oil-free moisturising…the leaflet inside the Tretinoin box says to use oil-free moisturisers only. However, I’m finding the only thing my skin can tolerate with the tretinoin is face oils/anhydrous balms. All of my “super sensitive” water based creams cause an intolerable burning and I have to wash them off and apply the balms/oils several times a day so I can still move my face!

I was wondering – is there any science behind using oil-free moisturiser for acne (or for use with tretinoin generally)? I’ve read a lot of conflicting information on the internet but I think this is a really interesting topic…I have oily acne prone skin with hyperpigmentation and I haven’t found swapping out oils for oil-free moisturisers has ever made a difference to my skin situation.

Thanks again for this post (and all of your posts). Your content is really helpful and very engaging.

Maddi

I think the ‘mask’ technique is working pretty well for me, but my pharmacist recommended starting with a 1 hour mask and adding an extra hour each night I use it before washing off and moisturizing like crazy. I’m using a lower concentration than yours (0.025 vs. 0.05), and was instructed to use it every other night for the first two weeks, and every night after that.

I was also really surprised when both my doctor and pharmacist told me I should not use hyaluronic acid! I explicitly asked both of them after they said ‘no acids’, thinking it couldn’t possibly apply to something hydrating, and was surprised by their answers. It is very dry here (late fall in Canada), so maybe it has something to do with there not being enough humidity in the air to hold onto? For now I’ve switched to squalane oil, but I’m hoping to add some of my old products back in as I adjust to the treatment. (Although I have sort of been cheating with my niacinamide serum that contains hylaluronic acid on my ‘off’ days)

Totally can go back to those once your skin is settled. I do both and use tret.