Our wallets can take a painful punch when we buy expensive medications. But do our bodies take a hit as well?

A recent study by scientists in Europe and the U.S. showed that people who thought they were using an expensive medication, but who actually got a placebo, reported more painful side effects.

The scientists offered a straightforward explanation that is more psychological than physical.

When we buy an expensive product, whether it’s a medication or a shampoo or the latest electronic gizmo, our expectation is that it will work better. Money equals quality, right? But when we’re talking about a drug, that’s not always the case.

So, how does this lead to more pain?

Researchers who published the study in the journal Science say we may perceive that those extra dollars buy a more potent medication. And, of course, we tend to accept that a drug with extra potency is going to produce better health benefits.

This is called the nocebo effect, in which a drug-trial subject’s symptoms are actually worsened by taking an inert substance, or a placebo.

The study recruited people who randomly got one of two medicated creams. Neither contained any medication, though patients were told both could make their skin more sensitive to pain. Researchers put one supposedly high-priced cream in fancy packaging, the other in pedestrian wrap.

In tests, those taking the fake pricey cream reported more pain, and the second group experienced little to no pain.

A real-world application of this knowledge is that doctors might explain the nocebo effect to patients so they don’t stop taking a useful drug simply because they feel it is inferior based on irrelevant information, such as colorful packaging.