I Used a $15 Drugstore Retinol and a $90 Serum for Eight Weeks. One Side of My Face Won.

I have spent an embarrassing amount of money on serums. So this fall I did the thing I always tell friends to do and never do myself: a proper split-face test. Drugstore retinol on the right side. A fancy $90 retinol serum on the left. Same cleanser, same moisturizer, same sunscreen, eight weeks.

The setup

The drugstore pick was a plain retinol serum in an opaque pump bottle, around $15 at Target and Ulta. The luxury one came in a gorgeous frosted glass dropper bottle and smelled like a spa. That smell should have been my first warning.

I used both three nights a week for the first two weeks, then every other night. I took photos in the same window light every Sunday. Boring, yes. But that's how you stop lying to yourself.

Weeks one to three: the purge nobody warns you about

Both sides got flaky. The left side, the expensive side, got angry. Red patches around the nose, a stinging feeling when I put on moisturizer. I checked the ingredient list again and there it was: fragrance and a couple of essential oils sitting right next to the retinol.

Retinol already makes your skin barrier cranky. Adding perfume on top is a choice. Not a good one.

The drugstore side flaked around the chin and that was it. By week three it had settled down.

Weeks four to eight: where the money went

Here's what surprised me. By week six, texture on both cheeks looked smoother in photos. Fine lines under the eyes looked about the same on both sides. The expensive side was a little more even in tone, but it also had more irritation to recover from, so I can't call it a clean win.

What I can say: the $15 bottle did roughly 80 percent of the work. Maybe more.

What actually matters on the label

• **Packaging.** Retinol breaks down with light and air. Opaque pump beats a clear dropper bottle every time, no matter how pretty the dropper is.
• **No fragrance.** If your retinol smells nice, someone decided marketing mattered more than your skin barrier.
• **A clear percentage or strength.** If the brand won't tell you how much retinol is in there, assume it's not much.
• **Buffering ingredients.** Niacinamide, ceramides, glycerin. These make the first month less miserable.

Where to buy without overpaying

Drugstore retinols go on sale constantly. Target runs beauty promos most months, and Ulta's 21 Days of Beauty event is where I'd stock up. Amazon is fine too, just buy from the brand's official storefront so you don't get an old bottle that's been cooking in a warehouse.

The luxury serum? I finished the bottle out of stubbornness. I won't rebuy it.

My honest verdict

If you're new to retinol, buy the cheap one. Use it twice a week. Wear sunscreen every single morning or don't bother at all, because retinol without SPF is just paying to make your skin more sensitive.

If you've used retinol for years and want something stronger, prescription tretinoin from a dermatologist will beat any luxury serum on the shelf. The pricey middle ground is mostly a nice bottle and a nice smell. And the smell was the problem.