AM vs PM: The Science of When to Use a Retinol Serum

Routine Science
Using retinol in the morning is a major mistake—here’s the science-backed reason it belongs strictly in your PM routine.
Expert Analysis · Honest Reviews · Real Results
1.🧪Sunlight Kills Retinol

Putting retinol on in the AM is like paying for a gym membership and then never going. A total waste.

UV light degrades it on contact—rendering it useless before it can even start working. The science is brutal and clear.

2.🌙The Night Shift Serum

This is The Ordinary‘s Retinol 0.5% in Squalane. Under $10. The claim? Real results without the luxury markup.

1

Mid-Strength

Strong enough to work, gentle enough to not nuke your skin barrier.

2

Squalane Base

An oil, but not a greasy one—it mimics your skin’s own lipids.

3

Dropper Bottle

You control the dose. Two drops max for the whole face.

white and blue plastic bottles on table

Photo: Angelina / Unsplash

3.☀️What’s Actually In It

It’s a two-ingredient show. Retinol to speed up cell turnover. Squalane to cushion the blow.

  • Retinol 0.5%: The workhorse that tells your skin to renew itself
  • Squalane: A hydrating oil that won’t clog pores
  • That’s it. Seriously.
  • No fragrance, no fluff.
4.🔬The Feel & The Flakes

Texture is a light amber oil. Absorbs in 60 seconds—leaves a slight film, not a slick.

Week 2: The purge is real. Tiny whiteheads. Then, by week 3, they vanished and my skin felt smoother. The turnaround was oddly satisfying.

💡

One Thing: Apply it *after* your moisturizer on damp skin. It buffers the intensity and prevents the dreaded retinol rash.
5.⚠️The Real Deal

After 6 weeks, my pores looked tighter. Texture improved. Did it erase fine lines? No. But it made my skin look fresher—like I’d had a good night’s sleep.

Buy if
You’re new to retinol and want to test the waters without a huge investment.
⏭️

Skip if
You have super sensitive, rosacea-prone skin. Start with their Granactive Retinoid instead.
💰

Worth it?
Absolutely. The price is a joke for what it does.
6.Strictly PM Business

A no-BS starter retinol that proves you don’t need to spend a fortune. Just remember: night only.

8.5/10
Effective, affordable, slightly fussy.
🛍️

Where to Buy: Sephora or the brand site. Get the 0.2% first if you’re nervous.