The Expensive Jar Isn't Always Doing More. Two Studies Say Why.

Earlier this week I mentioned I'd been putting together a fuller breakdown of the price question in skincare, the one that comes up every time a serum with a three-figure price tag lands in a shopping cart next to a $15 bottle doing, on paper, the same job. I said there'd be more on that soon. This is that.

The question underneath it is one most of us have stood with an actual jar in each hand and asked, whether we said it out loud or not. Does the $60 one do more than the $6 one? Not whether it feels nicer, not whether the packaging suggests more expertise. Does it actually perform better?

What a 174-product study actually measured

A team of dermatologists published a cohort study in JAMA Dermatology in 2017 that took a different approach to this question than most beauty coverage does. Instead of testing a handful of creams in a lab, they pulled data on the 174 best-selling moisturizers across Amazon, Target, and Walmart, along with more than 109,000 consumer reviews attached to those listings.

The price spread alone was startling. Per ounce, it ranged from about $0.10 to $9.51, a difference of roughly 9,400 percent for products doing, broadly, the same job. What the researchers were really after was whether that price difference tracked with anything meaningful, specifically fewer potentially irritating ingredients. It didn't. Products completely free of common contact allergens were not reliably more expensive than products that contained one or more of them. A jar could carry a real premium and still list the same allergens as something a fraction of the cost.

One detail from that same paper stuck with me longer than the allergen finding. Products labeled "dermatologist recommended" carried a real price premium over ones without that label, roughly $0.30 more per ounce. The study found no consistent difference in what was actually in the jar tied to that label. Sometimes a person is paying for four words on a box.

A separate cost analysis published in 2023 looked at nearly 800 sunscreen, retinol, vitamin C, and niacinamide products across four major retailers: Walmart, Ulta, Walgreens, and Amazon. It wasn't testing whether any of them worked. It was tracking what the same category of product costs depending on where a person happens to buy it, and the spread was large enough on its own: Walmart consistently the cheapest, Amazon consistently among the priciest, for what were often near-identical formulations. Retailer margin alone can explain a meaningful chunk of a price gap before you even get to what's actually in the bottle.

The stranger finding: the price tag might be working against you

The second study is one I didn't expect, and it's the real reason this piece exists. In a 2025 cross-sectional study, researchers recruited 88 patients from dermatology clinics at the University of California, San Francisco, gave each of them their own usual sunscreen, 32 different brands in total, ranging from $0.60 to just over $36 an ounce, and weighed the bottles before and after a single normal application to an arm or the face and neck.

What surprised the researchers had nothing to do with SPF or the ingredient list. It came down to behavior. As the price per ounce went up, the percentage of the recommended amount people actually applied went down, roughly one percent less applied for every extra dollar per ounce in cost. Some part of people just didn't want to burn through an expensive bottle that fast.

Which means a more expensive sunscreen, even one that would test identically to a cheaper one in a lab, can end up protecting a person less in real life, simply because they're more careful with it than the label wants them to be. The sunscreen isn't the problem. Price is, quietly changing how carefully we use the bottle.

Where this gets honest about its limits

Neither of these studies measured wrinkles, collagen, or how anyone's skin actually looked at the end of a season. The moisturizer study tracked reviews and ingredient lists, not skin outcomes; the sunscreen study tracked how much product left the bottle, not how well it protected anyone over a summer. I haven't found a large trial that puts a $200 cream and a $20 cream on the same faces and measures the visible result directly. If a study like that exists, it's smaller and narrower than the marketing built on top of the general idea suggests.

That gap matters as much as either finding on its own. The honest answer to "does the expensive jar do more" is closer to "nobody has measured that as directly as most of us would like" than to "no, cheap always wins." Both of those are more useful to sit with than a confident claim in either direction.

What I've actually changed

I stopped assuming the number on a jar tells me anything about what's inside it, and I started checking the same handful of words on the label instead: ceramide, niacinamide, and the SPF number itself. I also apply sunscreen the way the bottle actually recommends now, not the way that makes an expensive bottle stretch through August.

This is the kind of thing I wanted a single place to hold, with the actual sources sitting next to each claim instead of scattered across three weeks of reading. That's what became Skin After 40, an 18-page workbook walking through what's actually been tested in skincare after 40: sunscreen, moisturizer, retinoids, collagen, the price question included, with the type of study, the sample size, and the source linked next to every claim in it.

No pressure at all if this isn't the moment for it. But if you've ever stood in an aisle doing the same math I was doing, the workbook is there.